Lins P E, Petersson B, Efendić S
Acta Physiol Scand. 1980 Nov;110(3):267-75. doi: 10.1111/j.1748-1716.1980.tb06663.x.
Infusion of cyclic somatostatin (700 mg/kg/min) for 4 h in rat fed and libitum suppressed basal insulin but not glucagon release. It was accompanied by hypoglycemia during the first hour whereas, at the end of the infusion, hyperglycemia was present. The same dose of somatostatin applied 60 min prior to and during a 30 min load of glucose or arginine significantly inhibited their effects on insulin and glucagon release. In contrast, when this dose of somatostatin was given during a 24 h period by the i.v. route it did not inhibit glucose induced insulin release though circulating somatostatin levels were constantly and markedly elevated. Furthermore, in rats continuously infused with somatostatin for 4 days, no effect was found either on plasma concentrations of glucose, insulin, glucagon, growth hormone and cyclic AMP, or on body weight gain, food consumption or water intake. The pancreases of these animals showed normal concentrations of insulin and glucagon and a normal nuclear area of D-cells. Our experiments demonstrate that, in short-term experiments in rats, somatostatin influences insulin and glucagon release as well as glucose homeostasis. Furthermore, they suggest that during prolonged i.v. administration of somatostatin, rats develop mechanisms counteracting the effect of the peptide, e.g., peripheral tachyphylaxis.
以700毫克/千克/分钟的剂量给自由进食的大鼠静脉输注环孢素生长抑素4小时，可抑制基础胰岛素分泌，但不影响胰高血糖素的释放。输注的第一个小时会出现低血糖，而在输注结束时则会出现高血糖。在给予葡萄糖或精氨酸负荷前60分钟及负荷期间给予相同剂量的生长抑素，可显著抑制它们对胰岛素和胰高血糖素释放的影响。相反，当通过静脉途径在24小时内给予该剂量的生长抑素时，尽管循环生长抑素水平持续且显著升高，但它并未抑制葡萄糖诱导的胰岛素释放。此外，在连续4天输注生长抑素的大鼠中，未发现其对血糖、胰岛素、胰高血糖素、生长激素和环磷酸腺苷的血浆浓度有影响，对体重增加、食物消耗或水摄入量也无影响。这些动物的胰腺显示胰岛素和胰高血糖素浓度正常，D细胞的核面积也正常。我们的实验表明，在大鼠的短期实验中，生长抑素会影响胰岛素和胰高血糖素的释放以及葡萄糖稳态。此外，这些实验表明，在长期静脉注射生长抑素期间，大鼠会产生抵消该肽作用的机制，例如外周快速耐受。
