SEASONAL-CHANGES IN PANCREATIC B-CELL FUNCTION IN EUTHERMIC YELLOW-BELLIED MARMOTS
SEASONAL-CHANGES IN PANCREATIC B-CELL FUNCTION IN EUTHERMIC YELLOW-BELLIED MARMOTS
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DOI：
10.1152/ajpregu.1985.249.2.r159
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发表时间：
1985-01-01
影响因子：
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通讯作者：
BAUMAN, WA
中科院分区：
文献类型：
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作者：
FLORANT, GL;LAWRENCE, AK;BAUMAN, WA
在旱獭的整个体重周期中测定空腹血浆胰岛素（PI）和葡萄糖（PG）浓度。动物在夏季体重增加，在深秋体重达到峰值，之后停止进食。每个月向体温正常的动物动脉内注射葡萄糖（500 mg/kg）或猪胰岛素（0.1 U/kg），并在随后的2 h内采集血样。在体重增加期间，空腹PI浓度和胰腺B细胞对注射葡萄糖的反应显着增加。在体重峰值期间或体重最初开始下降时测量葡萄糖激发的最大胰岛素释放。外源性胰岛素给药后的PG浓度在秋季是轻微的（< 10%），但增加了约在土拨鼠减肥后的春天，基础PG水平全年无显著差异。基础空腹PI浓度在秋季显著升高（P < 0.01）。在秋天，当土拨鼠肥胖时，高胰岛素血症和外周胰岛素抵抗就会出现。此外，在2只动物中，体重增加约30%或更少，外周阻力是明显的，虽然没有明显的动物，适当增加了体重时，给予食物自由采食。肥胖以外的因素，即，食物摄入、中枢神经系统对胰腺B细胞的输入和/或B细胞对PG敏感性的变化可能导致观察到的外周胰岛素抵抗，并可能参与体重调节。
Fasting plasma insulin (PI) and glucose (PG) concentrations were measured throughout the body weight cycle of marmots. Animals gained weight during summer, and in late fall body weight peaked, after which they ceased feeding. Each month euthermic animals were injected intraarterially with either dextrose (500 mg/kg) or porcine insulin (0.1 U/kg), and blood samples were collected over the subsequent 2 h. During weight gain fasting PI concentration and pancreatic B-cell response to injected dextrose increased markedly. Maximal insulin release to a dextrose challenge was measured during peak body weight or when body weight initially began to decline. The PG concentration after exogenous insulin administration was slight (< 10%) in the fall but increased .apprx. 25% in the spring after marmots lost weight. Basal PG levels were not significantly different throughout the year. Basal fasting PI concentrations were significantly higher during the fall (P < 0.01). In the fall, when marmots are obese, hyperinsulinemia and peripheral insulin resistance appear. Furthermore, in 2 animals with an increase in body weight of .apprx. 30% or less over the summer, peripheral resistance was demonstrable, albeit not as marked as in animals that appropriately doubled their body weights when given food ad libitum. Factors other than adiposity, i.e., food intake, central nervous system input to the pancreatic B-cell, and/or changes in B-cell sensitivity to PG, may contribute to the observed peripheral insulin resistance and may be involved in body weight regulation.