BACKGROUND: Equine metabolic syndrome is an endocrinopathy that affects different breeds of horses and ponies. This metabolic disorder is a multifactorial syndrome and it is primarily linked to obesity, dyslipidemia and insulin resistance. OBJECTIVES: The present study was performed to evaluate insulin resistance in Darehshori horses with regards to age, sex, season and obesity. METHODS: Twelve adult stallions and 14 non-pregnant Darehshori breed mares were selected between January and November 2015. Fourteen horses were under and others were above 10 years old. Body condition scores of the animals were estimated based on Hennekes’ 1 to 9 scoring system, thus, 1 is poor and 9 is extremely fat horse. Body condition score of 12 horses was under 5 and the others above 5. The horses were studied during a period of one year, every 45 days and blood sampling and body condition scoring were performed at each time. Insulin resistance was assessed based on screening test. Serum concentrations of glucose, insulin and leptin were determined. RESUTLS: This study comprehensively used multiple detailed parameters to scan thoroughly the concept of insulin resistance in Darehshori horses on a long term basis. The levels of insulin, glucose and leptin in aged and obese stallions in warmer months were significantly higher than the others and reference range (P<0.05), hence, insulin resistance was detected in these groups of studied animals. CONCLUSIONS: These findings represented insulin resistance phenomenon in a specific breed in Iran. The physiologic characteristics of this breed may be different from other ones and the conditions in Iran such as climate are different from other countries. Hence, it should be considered that Darehshori horses have unique characteristics compared with other breeds. The study may be used as a guideline for evaluating the insulin resistance in Darehshori horses.

BACKGROUND: Mesobuthus eupeus is an indigenous scorpion species in Southwest Iran which is respon- sible for the majority of scorpion sting cases in Khuzestan province. OBJECTIVES: The effects of M. eupeus venom were investigated on the chief metabolic hormones in rats. METHODS: A total of 45 Albino male rats were divided into 3 equal groups: group 1 (control): 0.5 ml normal saline was administered intraperitoneally (IP); group 2 and 3: M. eupeus venom was administered with a dose of 1 and 2 mg/kg IP, respectively. Sampling was performed at 8, 24, and 48 hours after venom/ saline injection. RESULTS: The levels of thyroxine (T4) and triiodothyronine (T3) were significantly lower in both venom receiving groups (groups 2 and 3) than in the control group, dose-dependently, at all sampling times. There was a significant decrease in insulin level in both intoxicated groups compared to the control group at all sampling times. Glucagon, cortisol and subsequently glucose concentrations were significantly increased in both groups receiving the venom (groups 2 and 3) compared to the control group at 8 and 24 hours following envenomation. CONCLUSIONS: The findings of this study indicate that M. eupeus venom can suppress the secretion of essential metabolic hormones including T3, T4, and insulin and stimulate the release of glucagon, and cor- tisol, leading to hyperglycemia.