Effects of Heat Exposure on Adrenergic Modulation of Insulin and Glucagon Secretion in Sheep

Endocrine Journal

MITSUTO MATSUMOTO¹  KOICRN HODATE¹  AKIHITO OZAWA¹  FUMIAKI ITOH¹  SHINICHIRO KOYAMA¹  YOSHIAKI OBARA²  MICHAEL T ROSE³ 

[1] Department of Animal Physiology, National Institute of Animal Industry;Faculty of Agriculture, Tohoku University;Institute of Rural Studies, University of Wales

关键词: Insulin;    Glucagon;    Heat exposure;    Adrenergic modulation;    Sheep;   

DOI  :  10.1507/endocrj.48.193

学科分类：内分泌与代谢学

来源: Japan Endocrine Society

【 摘 要 】

References(14)Cited-By(3)The effects of heat exposure on the adrenergic modulation of pancreatic secretion were investigated. Five ewes fed at maintenance level (ME base) were housed in thermoneutral (TN; 20°C) and hot (30°C) environments. Heat exposure caused an increase in respiration rate and a slightly higher rectal temperature, and decreases in basal insulin and glucose concentrations. Infusions of saline plus epinephrine caused increases in glucagon and glucose concentrations, and no significant change in insulin secretion. Phentolamine (an adrenergic α-antagonist) plus epinephrine augmented insulin secretion; however, this insulin secretory response was inhibited by heat exposure. Propranolol (a β-antagonist) plus epinephrine produced a slight decrease in insulin secretion in the TN environment, whereas no effect was observed during heat exposure. While glucagon secretion through α-adrenergic stimulation was not affected by heat exposure, homeostatic signals controlling insulin release seemed to be affected during heat exposure. We thus hypothesised that insulin concentration is decreased in sheep fed at maintenance level in hot environments, and that this response is mediated in part by a modulation of β-adrenergic function.

【 授权许可】

Unknown