BACKGROUND: The decreases in insulin sensitivity and extensive perinatal lipolysis are common causes of metabolic diseases related to energy metabolism in ewes. OBJECTIVES: The present study was designed to study the effect of organic zinc on glucose metabolism and insulin resistance indices in early lactating ewes. METHODS: 18 Ghezel ewes were divided into three groups based on organic zinc supplementation, including CTR: (basal diet without Zinc), LZn: (basal diet supplemented with 30 mg Zn/kgDM) and group 3, HZn: (basal diet supplemented with 300 mg Zn/kgDM). RESULTS: The results of this study showed no significant differences between the experimental groups in glucose, NEFAs, BHB, cholesterol, triglyceride, and insulin concentrations. Furthermore, the effect of zinc on the insulin to glucose ratio was not significant among the experimental groups (p < /em>>0.05). Supplementation of zinc-methionine significantly increased serum zinc concentration in ewes (p < /em><0.001). The area under the curve (AUC60, AUC120) was the highest for the control group and LZn and the lowest for HZn group (p < /em><0.05). The rate of glucose clearance in zinc-methionine supplement recipients was higher compared to the control group. The time to reach half maximal glucose concentration in zinc treated ewes was significantly lower than that of the control group (p < /em><0.001), indicating an improvement in insulin sensitivity and glucose metabolism. CONCLUSIONS: Our findings indicate that Zinc is effective in improving the NEB and preventing insulin resistance in early lactation. It is possible that in sheep, the tissue responsiveness to insulin is enhanced with dietary Zn supplementation, and present findings suggest that dietary Zn-Met may improve energy balance and insulin resistance in lactating ewes.

BACKGROUND: Leucine is one of the subgroups of amino acids, which play an important role in the anabolism of muscles, adipose tissue, and the liver by stimulating insulin secretion.OBJECTIVES: Effects of different levels of leucine were investigated on carcass yield, characteristics, and quality, and expression of insulin-like growth factor (IGF-1) and insulin genes in male broilers.METHODS: Five levels of L-leucine (100, 110, 120, 130, and 140 % of Ross strain requirements) were tested with 250 male one-day-old chicks in a completely randomized design with five treatments and five replicates (containing 10 chicks each). On day 42 of their age, the blood samples of two birds from each replicate (10 birds per treatment) were taken to determine serum IGF-1 gene expression. Subsequently, these birds were slaughtered for analysis of carcass characteristics and quality, and collecting the samples of liver and breast for expression of IGF-1 and insulin genes.RESULTS: Body weight increased by consumption of 140 % of leucine as compared to 100 %. Reduction in feed conversion ratio was observed by feeding 140 % of leucine level. The IGF-1 gene expression of breast and liver increased by 110 % of leucine level. Moreover, feeding 110 % of leucine level caused a higher expression of insulin gene in breast and liver. Consumption of 130 % of leucine improved the meat protein, fat, and ash contents. Furthermore, consumption of 110 % of leucine increased the serum IGF-1 concentration.CONCLUSIONS: Consumption of leucine in broiler diets was found to increase the expression of IGF-1 and insulin genes and consequently, improve the performance and carcass quality. It also decreased the abdominal fat in broiler chickens.

Plasma insulin concentration of many species has a characteristic early or acute-phase response in the minutes after IV administration of glucose, However, the plasma insulin response of horses soon after the Iv administration of glucose has not been examined, whereas the more prolonged response has been evaluated. We examined the plasma insulin and glucose concentration responses of adult mares during the 30 minutes after rapid Iv administration of glucose (0.33 g/kg of body weight). Plasma glucose concentration peaked at 664 +/- 54 mg/dl within I minute of cessation of glucose administration, whereas insulin concentration peaked at 326 +/- 24 pmol/L at 2 minutes after the end of glucose administration. Thus, these mares had an acute insulin response, consistent with that observed in other species, including dogs, human beings, and cattle.

This study investigated the effects of intragastric administration of apelin-13 on the secretion of critical pancreatic hormones in a cohort of three-week-old Wistar rats. The research aimed to uncover apelin’s modulatory roles in endocrine interactions dictating metabolic homeostasis during early life.

OBJECTIVE To develop a technique for isolation and culture of canine insulinoma cells and assess expression of cellular hexokinases (glucokinase and hexokinase I) and expression and secretion of insulin from these cells in vitro. SAMPLE Pancreatic insulinomas and normal pancreatic tissue from 4 and 3 dogs, respectively. PROCEDURES Tissues were collected by surgical excision or at necropsy. Insulinoma cells from 2 dogs were cultured for up to 10 weeks with standard techniques; insulin synthesis in vitro was confirmed by immunohistochemical analysis of freshly prepared slides of cultured cells, and insulin secretion was assessed by measurement of insulin concentrations in culture medium with an ultrasensitive mouse insulin ELISA. Expression of cellular hexokinases in insulinomas and adjacent normal (nontumor) pancreatic tissue from the same dog (n = 3) was examined by quantitative reverse transcriptase PCR assay. RESULTS Insulinoma cells survived for up to 10 weeks but did not proliferate in culture. Insulin was detected in isolated cells and secreted into culture medium for up to 10 weeks. Both cellular hexokinases were expressed; glucokinase appeared to be overexpressed in insulinomas, compared with normal pancreatic tissue from the same dogs. CONCLUSIONS AND CLINICAL RELEVANCE Canine insulinomas expressed hexokinases responsible for glucose responsiveness. Insulinoma cells were successfully maintained in short-term culture; cultured cells remained functional for 10 weeks as evidenced by cellular insulin content and had detectable secretion of insulin into the culture medium for ≥ 5 weeks. Apparent glucokinase overexpression by insulinomas suggested a possible mechanism underlying excessive insulin release by these tumors.