Tityus serrulatus envenoming in non-obese diabetic mice: a risk factor for severity
© The Author(s). 2016
Received: 29 March 2016
Accepted: 2 September 2016
Published: 17 September 2016
In Brazil, accidents with venomous animals are considered a public health problem. Tityus serrulatus (Ts), popularly known as the yellow scorpion, is most frequently responsible for the severe accidents in the country. Ts envenoming can cause several signs and symptoms classified according to their clinical manifestations as mild, moderate or severe. Furthermore, the victims usually present biochemical alterations, including hyperglycemia. Nevertheless, Ts envenoming and its induced hyperglycemia were never studied or documented in a patient with diabetes mellitus (DM). Therefore, this is the first study to evaluate the glycemia during Ts envenoming using a diabetic animal model (NOD, non-obese diabetic).
Female mice (BALB/c or NOD) were challenged with a non-lethal dose of Ts venom. Blood glucose level was measured (tail blood using a glucose meter) over a 24-h period. The total glycosylated hemoglobin (HbA1c) levels were measured 30 days after Ts venom injection. Moreover, the insulin levels were analyzed at the glycemia peak.
The results demonstrated that the envenomed NOD animals presented a significant increase of glycemia, glycosylated hemoglobin (HbA1c) and insulin levels compared to the envenomed BALB/c control group, corroborating that DM victims present great risk of developing severe envenoming. Moreover, the envenomed NOD animals presented highest risk of death and sequelae.
This study demonstrated that the diabetic victims stung by Ts scorpion should be always considered a risk group for scorpion envenoming severity.
KeywordsTityus serrulatus Diabetes mellitus Scorpion venom NOD mice Glycemia
In Brazil, accidents involving venomous animals are considered a public health problem. Tityus serrulatus (Ts), popularly known as the yellow scorpion, is most frequently responsible for these accidents. During the period from 2000 to 2015, 727,113 cases of scorpion envenoming were reported in Brazil, with 1026 deaths and a mortality rate of 0.14 % [1–4].
Envenoming by Ts can cause several signs and symptoms according to not only the content of venom, but also the victim’s body weight, the blood-brain-barrier permeability, sex, health conditions and sting location. The mild envenoming is characterized by an intense local pain and possible paresthesia. Moderate envenoming manifests through local pain as well as nausea, sweating, vomiting, tachycardia, tachypnea and increasing of blood pressure. Severe envenoming presents the same symptoms of moderate followed by agitation and exhaustion, abdominal pain, stiffness and muscle spasms, convulsions, fever, dehydration, cardiac arrhythmias, heart failure and even coma [5–11]. Moreover, biochemical alterations are also observed during Ts envenoming such as hyperglycemia [6, 12–15].
Hyperglycemia is a sign constantly observed in diabetic individuals. Diabetes mellitus (DM) currently affects about 314 million people worldwide. Solely in 2012, it was responsible for 1.5 million deaths according to the World Health Organization (WHO). Currently, based on the etiology of the disease, DM can be classified into two types: type 1 and type 2 . Although the pathologies have different origins, both have similar signs and symptoms such as hyperglycemia, polyuria, polyphagia, polydipsia, unexplained weight loss and may also include foot pain, blurred vision, frequent infections and even coma [17, 18].
The type 1 DM, or insulin-dependent DM, has a genetic etiology with the most common type being among children and juveniles. It is an autoimmune disease in which self-reactive T cells induce the B cell production of specific antibodies against beta cells of the islets of Langerhans. This autoimmune mechanism results in the destruction of these cells and consequently the decrease of insulin production [19, 20]. On the other hand, type 2 DM is the most common type of diabetes (accounts for 90 %). It is considered a chronic metabolic disorder and has been characterized by impaired insulin action and/or abnormal insulin secretion and eventual pancreatic beta-cell failure. An early abnormality in the disease is insulin resistance, which is the key linking factor for the metabolic syndrome disease cluster of glucose intolerance, hypertension and dyslipidemia [21–23].
The model employing non-obese diabetic (NOD) animals is useful for type 1 diabetes, and presents an autoimmune genetic disease where T cells (CD4+andCD8+) become self-reactive to pancreatic islets, resulting in inflammation during the first 3 to 4 weeks of life. However, only after mice reach 4 to 6 months of age does it become possible to verify insulitis, which results in insulin deficiency and therefore the clinical signs of diabetes [24, 25]. Thus, based on the Ts venom-induced hyperglycemia and the high incidence of diabetic patients, this is the first study to investigate the Ts envenoming complications in DM individuals, using NOD mice as the experimental model.
T. serrulatus venom
The Ts scorpions, collected from the Ribeirão Preto region, were kept in the Serpentarium of the Medical School of RibeirãoPreto (FMRP/USP). The venom extraction from 145 scorpions was performed using the telson electrical stimulation method ─ 12 mV . After extraction, the pooled venom was desiccated and stored at –20 °C. The use of Ts venom was approved by the Genetic Patrimony Management Board (CGEN/MMA), through the Access and Shipment Component of Genetic Heritage for scientific research purposes (number 010174/2014-1).
Mass assessment of the venom of T. serrulatus
The desiccated venom was dispersed in 1 mL of ultrapure water and centrifuged at 10,015 × g, 4 °C for 10 min, and the supernatant was stored at 4 °C. The pellet was resuspended using the same conditions. The total supernatant (2 mL) resulted in soluble pooled venom without the presence of mucus.
The venom was analyzed using tricine sodium dodecyl sulfate polyacrylamide gel electrophoresis (Tricine-SDS-PAGE) according to the method used for ultra-low-mass proteins . The 16.5 % separating gel used was overlaid by a 5 % stacking gel. Samples consist of different masses of Ts venom (10, 20 and 30 μg) and the molecular mass marker (M-3546, Sigma-Aldrich®, USA). The gel was stained with Coomassie Blue plus one PhastGel® R-350 (GE Healthcare, Sweden) and destained with 10 % acetic acid (V/V).
Females of BALB/c and NOD lineage (18–25 g) were obtained from the biotherium of the School of Pharmaceutical Sciences of Ribeirão Preto (FCFRP/USP) and the biotherium of the Ribeirão Preto Medical School (FMRP/USP), respectively. The animals were kept in cages with filters in an air-conditioned environment (23 ± 1 °C, 55 ± 5 % humidity) until the blood glucose values of NOD animals became significantly higher than those of the controls (BALB/c), indicating the hyperglycemia characteristic of the diabetic state (15 weeks old). Food and water were provided ad libitum. Mouse experimental models are in accordance with the Ethical Principles in Animal Experimentation under the license number 13.1.372.53.0.
Basal blood glucose levels and T. serrulatus venom dose
The basal glucose levels of BALB/c and NOD mice were measured in tail blood using a glucose meter (One Touch Ultra®, Lifescan, USA). The dose of Ts venom capable of inducing hyperglycemia in mice (BALB/c and NOD) was also adjusted. The doses of 1 mg/kg and 0.5 mg/kg were tested in the different mouse species.
Kinetic assay of glucose induced by T. serrulatus venom
Groups of female BALB/c or NOD mice (18–25 g, n = 4) were challenged with a non-lethal dose of Ts venom (0.5 mg/kg) using subcutaneous injection (similar to scorpion sting site), diluted in sterile physiological solution (0.9 % W/V of NaCl) in a final volume of 0.2 mL. Control groups received only sterile physiological solution. Glucose was measured in tail blood using a glucose meter (One Touch Ultra®, Lifescan, USA). Blood glucose was measured over a 24-h period (at 0, 1, 2, 3, 4, 5, 6, 12 and 24 h).
Glycosylated hemoglobin (HbA1c) induced by T. serrulatus venom
Groups of female BALB/c or NOD mice (18–25 g, n = 4) were challenged with a non-lethal dose of Ts venom (0.5 mg/kg) using subcutaneous injection (similar to scorpion sting site), diluted in sterile physiological solution (0.9 % W/V of NaCl) in a final volume of 0.2 mL. Control groups received only sterile physiological solution. After 30 days (to reflect mean glycemia for the previous 30 days), 0.5 mL of blood from the retro-orbital cavity was collected in heparinized tubes under intraperitoneal anesthesia: ketamine 60 mg/kg (Dopalen, Agripands Brasil Ltda®, Brazil) and xylazine 8 mg kg (Rompun, Bayer Animal Health®, Brazil). The blood was centrifuged at 10,000 rpm for ten minutes, at 4 °C, to obtain the plasma. The measurement of total glycosylated hemoglobin (HbA1c) levels was performed according to the manufacturer’s instructions (Doles®, Brazil).
Insulin levels induced by T. serrulatus venom
Groups of female BALB/c or NOD mice (18–25 g, n = 4) were challenged with a non-lethal dose of Ts venom (0.5 mg/kg) using subcutaneous injection (similar to scorpion sting site), diluted in sterile physiological solution (0.9 % W/V of NaCl) in a final volume of 0.2 mL. Control groups received only sterile physiological solution. After reaching the hyperglycemia peak (1 h after envenomation), 0.5 mL of blood from the retro-orbital cavity was collected in heparinized tubes under anesthesia. The blood was centrifuged at 10,000 rpm for 10 min, at 4 °C, to obtain the plasma. The insulin assay was performed using the immunoassay method according to the manufacturer’s instructions (Ultra Sensitive Mouse Insulin ELISA kit, Crystal Chem, USA).
T. serrulatus venom mass and electrophoresis
The pooled venom obtained from 145 Ts scorpions resulted in 21 mg of soluble venom, a median of 0.14 mg per scorpion.
T. serrulatus venom increased the glucose levels of mice
T. serrulatus venom affected the glycosylated hemoglobin (HbA1c) of NOD mice
T. serrulatus venom increased insulin levels of NOD mice
The insulin levels were analyzed in mouse plasma during the peak of hyperglycemia (1 h after envenoming). The results demonstrate that Ts venom did not change insulin levels in BALB/c mice (Fig. 4b). As to the NOD group, a significant increase of insulin was observed in the envenomed mice. On the other hand, no significant changes on insulin levels were found in the NOD control group.
The venom of T. serrulatus (Ts) is widely studied especially because of its biologically active compounds including the neurotoxins, a class of peptides mostly specific to voltage-gated sodium (Nav) or potassium (Kv) channels . So far, the actions of Ts neurotoxins on Nav and Kv channels have demonstrated a gamut of physiological responses, including the increasing of plasma glucose levels [14, 15, 30–40]. Although the mechanism of hyperglycemia induced by scorpions’ venom is not clearly understood, there are studies demonstrating that it can occur through the excessive release of catecholamine, increases in glucagon and cortisol, and alterations in thyroid hormone levels or insulin secretion [41–43]. Furthermore, an isolated α-toxin from Ts, denominated Ts5, demonstrated a direct effect on isolated islets of Langerhans (not provided by catecholamine’s action), enhancing β-cell membrane depolarization and significantly potentiating glucose-induced insulin secretion . Therefore, this pioneering study aimed to elucidate the effect of hyperglycemia induced by Ts venom in diabetic individuals, using a NOD mouse model.
The Ts pooled venom used in the study showed a protein profile similar to others previous described, presenting protein masses corresponding to neurotoxins specific to sodium (NaTxs) and potassium (KTxs) channels [27, 44].
The in vivo assays demonstrated that blood glucose levels significantly increase 1 h after Ts injection (0.5 mg/kg), independently of the mouse model. Indeed, the highest glucose level at 1 h after envenoming has already been described in Wistar rats using the same dose (0.5 mg/kg) and intraperitoneal (i.p.) injection, and in BALB/c mice using 1 mg/kg of Ts venom and subcutaneous (s.c.) injection [14, 15]. A peculiar observation during our experimental design standardization was that either the highest dose of Ts venom (1 mg/kg) or the highest glucose basal levels (≥200 mg/dL) cause NOD mice lethality. Furthermore, the surviving mouse that presented basal glucose ≥ 200 mg/dL and received 0.5 mg/kg of Ts venom (n = 1) demonstrated a clinical sequela represented by an ocular disease with partial loss of vision, probably retinopathy (Additional file 1).
The retina is an insulin-sensitive tissue and excess glucose or lipids may exert their noxious effects, accelerating retinal cell death . NOD mice frequently present diabetic retinopathy, with histological analysis showing loss of retinal microvessels and reduced perfusion of the retina, which result in hypoxia with evidence of disordered focal proliferation of new vessels . Definitely, diabetic retinopathy is a frequent cause of blindness developed by diabetic individuals after macular edema . Nevertheless, the retinopathy induced by Ts venom in diabetic mice requires further investigation.
During the Ts venom-induced glucose kinetic assay, we also observed a period in which the glucose reached levels lower than basal glycemia, which was previously described as a hypoglycemic period [14, 15]. BALB/c mice reduced glucose levels at 4 h following Ts venom injection, while NOD demonstrated a prolonged decrease of glucose levels at 5 to 6 h following Ts venom injection. It is known that beta cells of the islets of Langerhans sense changes in the plasma glucose levels and adjust the rate of insulin production aiming to maintain the homeostatic glucose plasma concentration . Thus, we assume that the production of insulin to control hyperglycemia induced by such envenoming remains high and, along with a decrease in glycogenolysis (due to hepatic glycogen depletion), causes a reduction of glucose levels.
Regarding NOD animals, the delayed hypoglycemia can be explained by the higher glucose levels required to be controlled, and the prolonged hypoglycemia (2 h) by the higher rates of insulin production. Indeed, a significant increasing of insulin was observed in NOD animals challenged with Ts venom. Although the increasing of this hormone in NOD mice seems peculiar, we assume that their diabetic disease was not sufficiently advanced to impair the insulin production significantly (the decrease of basal insulin of NOD control animals was not statistically significant compared to BALB/c control). In this sense, the animals still present a number of suitable insulin-producing beta cells in the islets of Langerhans.
According to the literature, the NOD model acquires insulin deficit after the age of 14 weeks (with high variety among individuals), that is, before this period, despite presenting high glucose levels, the animals still produce insulin. On the other hand, when these mice become overtly diabetic, they quickly lose weight and require insulin treatment . The effect of high insulin levels observed in NOD-envenomed mice is somewhat controversial. This effect may be beneficial, since insulin treatment in scorpion sting victims is known as a metabolic support, which controls the adverse metabolic response produced by catecholamines and other counter-regulatory hormones ; or it could be unfavorable, since the injection of insulin after Ts envenoming can enhance the venom’s lethality . Based on the latter, the lethality induced by Ts sting among diabetic individuals should be higher than that in healthy humans. In any case, insulin therapy after Ts envenoming should be further investigated in diabetic individuals, especially insulin-dependent ones.
On the other hand, BALB/c envenomed group did not present differences in insulin production compared to BALB/c control, although hyperinsulinemia has been reported previously during envenoming by the scorpion Mesobuthus tamulus concanesis and even by T. serrulatus [15, 42]. However, in the Ts study, the authors used a rat model and i.p. injection, which may justify such differences.
We also evaluated the glycosylated hemoglobin (HbA1c) percentage, which is the primary method recommended before initiating therapy in diabetes patients . Our results demonstrated that NOD control animals surely presented a diabetic clinical condition showing HbA1c higher than 7 % while the NOD envenomed group displayed a significant elevation, with levels higher than 8 %. The augmentation of HbA1c is considered a risk factor for diabetic neuropathy and retinopathy . This also explains why we observed only an ocular alteration in the envenomed group of NOD mice.
Currently, the treatment used for Ts accidents varies according to the clinical severity, which depends on the signs and symptoms manifested by the patient. Mild and moderate cases of Ts envenoming consist mostly of pain relief through analgesics at the sting site, orally or parenterally. On the other hand, severe scorpion envenoming cases require the mandatory use of the specific antivenom. In Brazil, the available antivenoms used for Ts envenoming are the scorpion antivenom (SAE or soro antiescorpiônico in Portuguese) and the arachnid antivenom (SAAr or soro antiaracnídeo in Portuguese). Their use is also compulsory in children under 7 years and in adults with previous health problems (e.g. hypertension and cardiovascular problems) even if they present mild or moderate clinical manifestations [1, 53]. In this regard, our results support the hypothesis that diabetic victims present a higher risk of developing severe envenoming. Therefore, we also advise consideration of the use of antivenom in cases of Ts envenoming in diabetic persons ─ a risk group for Ts envenoming severity.
Our study, for the first time, experimentally demonstrates that accidents caused by Ts scorpion in diabetic patients should be always considered a severe case of envenoming and that greater attention should be given to these cases. Moreover, as well as the envenomed NOD animals, these patients can present a higher risk of death and sequelae. We suggest that glucose, insulin and HbA1c levels need to be carefully monitored in diabetic patients.
Neurotoxin specific potassium channels
Voltage-gated potassium channel
Neurotoxin specific sodium channels
Voltage-gated sodium channel
Sodium dodecyl sulfate
Thanks to the Center for the Study of Venoms and Venomous Animals (CEVAP) of UNESP for enabling the publication of this paper (CAPES – grant n. 23038.006285/2011-21, AUXPE – Toxinologia – 1219/2011).
This study received financial support from the State of São Paulo Research Foundation (FAPESP –scholarships to MBP 2012/12954-6 and FAC 2012/13590-8), the National Council for Scientific and Technological Development (CNPq – scholarship to GHO) and NAP-TOXAN-USP (grant n. 12e125432.1.3).
GHO was the baccalaureate student (Iniciação Científica) responsible for the project, and was involved in the organization and execution of the experimentation section, data acquisition, statistical analysis and data interpretation, as well as drafting and revising the manuscript. MBP and ECA were the advisor researchers of this project and critically revised the manuscript for its content. FAC and IAC substantially contributed to the experimental execution and revision of the manuscript. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
Ethics approval and consent to participate
The present study was approved by the Ethics Commission for the Use of Animals (CEUA) at the USP Campus in Ribeirão Preto (protocol number 13.1.372.53.0). The use of Ts venom was approved by the Genetic Patrimony Management Board (CGEN/MMA), through the Access and Shipment Component of Genetic Heritage for scientific research purposes (number 010174/2014-1).
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Pucca MB, Oliveira FN, Schwartz EF, Arantes EC, da Silva RM L. Scorpionism and dangerous species of Brazil. In: Gopalakrishnakone P, editor. Scorpion Venoms. Netherlands: Springer; 2015. p. 299–324.Google Scholar
- SUS, Portal da Saúde: Situação Epidemiológica - Dados. 2016. http://portalsaude.saude.gov.br. Accessed 25 Jan 2016.
- Reckziegel GC, Pinto VL. Scorpionism in Brazil in the years 2000 to 2012. J Venom Anim Toxins incl Trop Dis. 2014;20:20–46.View ArticleGoogle Scholar
- Chippaux JP. Epidemiology of envenomations by terrestrial venomous animals in Brazil based on case reporting: from obvious facts to contingencies. J Venom Anim Toxins incl Trop Dis. 2015;21:13.View ArticlePubMedPubMed CentralGoogle Scholar
- Bucaretchi F, Fernandes LC, Fernandes CB, Branco MM, Prado CC, Vieira RJ, et al. Clinical consequences of Tityus bahiensis and Tityus serrulatus scorpion stings in the region of Campinas, southeastern Brazil. Toxicon. 2014;89:17–25.View ArticlePubMedGoogle Scholar
- Amitai Y. Clinical manifestations and management of scorpion envenomation. Public Health Rev. 1998;26(3):257–63.PubMedGoogle Scholar
- Guidine PA, Cash D, Drumond LE, de Souza ERGH, Massensini AR, Willilams SC, et al. Brainstem structures are primarily affected in an experimental model of severe scorpion envenomation. Toxicol Sci. 2014;137(1):147–57.View ArticlePubMedGoogle Scholar
- Amaral CF, de Rezende NA, Freire-Maia L. Acute pulmonary edema after Tityus serrulatus scorpion sting in children. Am J Cardiol. 1993;71(2):242–5.View ArticlePubMedGoogle Scholar
- Bahloul M, Chaari A, Dammak H, Algia NB, Bouaziz M. Nosocomial scorpion envenomation: an unusual mode of scorpion sting. Clin Toxicol (Phila). 2010;48(9):962.View ArticleGoogle Scholar
- Nishioka SA, Silveria PV, Pereira CA. Scorpion sting on the penis. J Urol. 1993;150(5 Pt 1):1501.Google Scholar
- Nunan EA, Moraes MF, Cardoso VN, Moraes-Santos T. Effect of age on body distribution of Tityustoxin from Tityus serrulatus scorpion venom in rats. Life Sci. 2003;73(3):319–25.View ArticlePubMedGoogle Scholar
- Fukuhara YD, Reis ML, Dellalibera-Joviliano R, Cunha FQ, Donadi EA. Increased plasma levels of IL-1beta, IL-6, IL-8, IL-10 and TNF-alpha in patients moderately or severely envenomed by Tityus serrulatus scorpion sting. Toxicon. 2003;41(1):49–55.View ArticlePubMedGoogle Scholar
- Cusinato DA, Souza AM, Vasconcelos F, Guimarães LF, Leite FP, Gregório ZM, et al. Assessment of biochemical and hematological parameters in rats injected with Tityus serrulatus scorpion venom. Toxicon. 2010;56(8):1477–86.View ArticlePubMedGoogle Scholar
- Pucca MB, Zoccal KF, Roncolato EC, Bertolini TB, Campos LB, Cologna CT, et al. Serrumab: a human monoclonal antibody that counters the biochemical and immunological effects of Tityus serrulatus venom. J Immunotoxicol. 2012;9(2):173–83.View ArticlePubMedGoogle Scholar
- Vasconcelos F, Sampaio SV, Garófalo MA, Guimarães LF, Giglio JR, Arantes EC. Insulin-like effects of Bauhinia forficata aqueous extract upon Tityus serrulatus scorpion envenoming. J Ethnopharmacol. 2004;95(2–3):385–92.View ArticlePubMedGoogle Scholar
- American Diabetes Association. Diagnosis and classification of Diabetes Mellitus. In Diabetes Care. 2004. p. S5,S6,S7,S8,S9,S10.
- Greene JA. A classification of the different types of diabetes mellitus with a discussion of the diagnosis and treatment of each. Ariz Med. 1946;3:158–61.PubMedGoogle Scholar
- World Health Organization (WHO). Global status report on noncommunicable diseases 2014. 2014 cited 2015; Available from: http://www.who.int/nmh/publications/ncd-status-report-2014/en/. Accessed 25 Jan 2016.
- Fukuda H. Report on a case of infantile diabetes. Showa Igakkai Zasshi. 1962;22:223-6. Article in Japanese.
- Pugliese A. Advances in the etiology and mechanisms of type 1 diabetes. Discov Med. 2014;18(98):141–50.PubMedGoogle Scholar
- Kasuga M. Molecular basis for the development of type 2 diabetes mellitus. Nihon Rinsho. 2002;60 Suppl 7:468–76. Article in Japanese.PubMedGoogle Scholar
- Olokoba AB, Obateru OA, Olokoba LB. Type 2 diabetes mellitus: a review of current trends. Oman Med J. 2012;27(4):269–73.View ArticlePubMedPubMed CentralGoogle Scholar
- Kahn CR. Banting Lecture. Insulin action, diabetogenes, and the cause of type II diabetes. Diabetes. 1994;43(8):1066–84.View ArticlePubMedGoogle Scholar
- Makino S, Kunimoto K, Muraoka Y, Mizushima Y, Katagiri K, Tochino Y. Breeding of a non-obese, diabetic strain of mice. Jikken Dobutsu. 1980;29(1):1–13.PubMedGoogle Scholar
- Chhabra G, Dixit A. Structure modeling and antidiabetic activity of a seed protein of Momordica charantia in non-obese diabetic (NOD) mice. Bioinformation. 2013;9(15):766–70.View ArticlePubMedPubMed CentralGoogle Scholar
- Lowe RM, Farrell PM. A portable device for the electrical extraction of scorpion venom. Toxicon. 2011;57(2):244–7.View ArticlePubMedGoogle Scholar
- Pucca MB, Amorim FG, Cerni FA, Bordon KC, Cardoso IA, Anjolette FA, et al. Influence of post-starvation extraction time and prey-specific diet in Tityus serrulatus scorpion venom composition and hyaluronidase activity. Toxicon. 2014;90:326–36.View ArticlePubMedGoogle Scholar
- Schagger H, von Jagow G. Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the separation of proteins in the range from 1 to 100 kDa. Anal Biochem. 1987;166(2):368–79.View ArticlePubMedGoogle Scholar
- Ortiz E, Gurrola GB, Schwartz EF, Possani LD. Scorpion venom components as potential candidates for drug development. Toxicon. 2015;93:125–35.View ArticlePubMedGoogle Scholar
- Pucca MB, Peigneur S, Cologna CT, Cerni FA, Zoccal KF, Bordon Kde C, et al. Electrophysiological characterization of the first Tityus serrulatus alpha-like toxin, Ts5: Evidence of a pro-inflammatory toxin on macrophages. Biochimie. 2015;115:8–16.View ArticlePubMedGoogle Scholar
- Peigneur S, Cologna CT, Cremonez CM, Mille BG, Pucca MB, Cuypers E, et al. A gamut of undiscovered electrophysiological effects produced by Tityus serrulatus toxin 1 on NaV-type isoforms. Neuropharmacology. 2015;95:269–77.View ArticlePubMedGoogle Scholar
- Cologna CT, Peigneur S, Rustiquel JK, Nonato MC, Tytgat J, Arantes EC. Investigation of the relationship between the structure and function of Ts2, a neurotoxin from Tityus serrulatus venom. FEBS J. 2012;279(8):1495–504.View ArticlePubMedGoogle Scholar
- Cerni FA, Pucca MB, Peigneur S, Cremonez CM, Bordon KC, Tytgat J, et al. Electrophysiological characterization of Ts6 and Ts7, K+ channel toxins isolated through an improved Tityus serrulatus venom purification procedure. Toxins (Basel). 2014;6(3):892–913.View ArticleGoogle Scholar
- Pucca MB, Cerni FA, Peigneur S, Bordon KC, Tytgat J, Arantes EC. Revealing the function and the structural model of Ts4: insights into the “non-toxic” toxin from Tityus serrulatus venom. Toxins (Basel). 2015;7(7):2534–50.View ArticleGoogle Scholar
- Cologna CT, Peigneur S, Rosa JC, Selistre de Araujo HS, Varanda WA, Tytgat J, et al. Purification and characterization of Ts15, the first member of a new alpha-KTX subfamily from the venom of the Brazilian scorpion Tityus serrulatus. Toxicon. 2011;58(1):54–61.View ArticlePubMedGoogle Scholar
- Zoccal KF, Bitencourt CS, Secatto A, Sorgi CA, Bordon KC, Sampaio SV, et al. Tityus serrulatus venom and toxins Ts1, Ts2 and Ts6 induce macrophage activation and production of immune mediators. Toxicon. 2011;57(7–8):1101–8.View ArticlePubMedGoogle Scholar
- Pessini AC, de Souza AM, Faccioli LH, Gregório ZM, Arantes EC. Time course of acute-phase response induced by Tityus serrulatus venom and TsTX-I in mice. Int Immunopharmacol. 2003;3(5):765–74.View ArticlePubMedGoogle Scholar
- Cupo P, Jurca M, Azevedo Marques MM, Oliveira JS, Hering SE. Severe scorpion envenomation in Brazil. Clinical, laboratory and anatomopathological aspects. Rev Inst Med Trop Sao Paulo. 1994;36(1):67–76.View ArticlePubMedGoogle Scholar
- D’Suze G, Moncada S, González C, Sevcik C, Aguilar V, Alagón A. Relationship between plasmatic levels of various cytokines, tumour necrosis factor, enzymes, glucose and venom concentration following Tityus scorpion sting. Toxicon. 2003;41(3):367–75.View ArticlePubMedGoogle Scholar
- Ribeiro EL, Pinto MC, Labarrere CR, Paes Leme FO, Chávez Olórtegui C, Melo MM. Biochemical profile of dogs experimentally envenomed with Tityus serrulatus scorpion venom. Toxicon. 2010;55(6):1125–31.View ArticlePubMedGoogle Scholar
- Murthy KR, Zare MA. Effect of Indian red scorpion (Mesobuthus tamulus concanesis, Pocock) venom on thyroxine and triiodothyronine in experimental acute myocarditis and its reversal by species specific antivenom. Indian J Exp Biol. 1998;36(1):16–21.PubMedGoogle Scholar
- Murthy KRK, Haghnazari L. The blood levels of glucagon, cortisol and insulin following the injection of venom by the scorpion (Mesobuthus tamulus concanesis, Pocock) in dogs. J Venom Anim Toxins. 1999;5(1):47–55.Google Scholar
- Goncalves AA, Toyama MH, Carneiro EM, Marangoni S, Arantes EC, Giglio JR, et al. Participation of Na(+) channels in the potentiation by Tityus serrulatus alpha-toxin TsTx-V of glucose-induced electrical activity and insulin secretion in rodent islet beta-cells. Toxicon. 2003;41(8):1039–45.View ArticlePubMedGoogle Scholar
- Pucca MB, Roncolato EC, Campos LB, Fernandes FS, Mendes GR, Bertolini TB, et al. Experimental Tityus serrulatus scorpion envenomation: age- and sex-related differences in symptoms and mortality in mice. J Venom Anim Toxins incl Trop Dis. 2011;17(3):325–32.View ArticleGoogle Scholar
- Antonetti DA, Barber AJ, Bronson SK, Freeman WM, Gardner TW, Jefferson LS, et al. Diabetic retinopathy: seeing beyond glucose-induced microvascular disease. Diabetes. 2006;55(9):2401–11.View ArticlePubMedGoogle Scholar
- Shaw SG, Boden JP, Biecker E, Reichen J, Rothen B. Endothelin antagonism prevents diabetic retinopathy in NOD mice: a potential role of the angiogenic factor adrenomedullin. Exp Biol Med (Maywood). 2006;231(6):1101–5.Google Scholar
- Munoz de Escalona-Rojas JE, Quereda-Castaneda A, Garcia-Garcia O. Update of diabetic retinopathy for Primary Care physicians: Towards an improvement of telematic medicine. Semergen. 2016;42(3):172–6. Article in Spanish.View ArticlePubMedGoogle Scholar
- Docherty K, Clark AR. Nutrient regulation of insulin gene expression. FASEB J. 1994;8(1):20–7.PubMedGoogle Scholar
- King AJ. The use of animal models in diabetes research. Br J Pharmacol. 2012;166(3):877–94.View ArticlePubMedPubMed CentralGoogle Scholar
- Murthy KR, Hase NK. Scorpion envenoming and the role of insulin. Toxicon. 1994;32(9):1041–4.View ArticlePubMedGoogle Scholar
- American Diabetes Association (ADA): standards of medical care for patients with diabetes mellitus. Diabetes Care. 1999;22(Supple. 1):32–41.
- McCarter RJ, Hempe JM, Gomez R, Chalew SA. Biological variation in HbA1c predicts risk of retinopathy and nephropathy in type 1 diabetes. Diabetes Care. 2004;27(6):1259–64.View ArticlePubMedGoogle Scholar
- Pucca MB, Cerni FA, Pinheiro Junior EL, Bordon KC, Amorim FG, Cordeiro FA, et al. Tityus serrulatus venom - A lethal cocktail. Toxicon. 2015;108:272–84.View ArticlePubMedGoogle Scholar