Tang F, Wong R P
Department of Physiology, Faculty of Medicine, University of Hong Kong, Hong Kong.
Biol Signals. 1996 Jan-Feb;5(1):44-50. doi: 10.1159/000109172.
The effects of streptozotocin-induced diabetes on pituitary neuropeptides were studied. Substance P, dynorphin and beta-endorphin in both pituitary lobes and cholecystokinin and somatostatin in the neurointermediate lobe (NIL) were measured 4 weeks after streptozotocin treatment in adult male rats. There were significant decreases of substance P levels in both the anterior lobe (AL) and NIL, and of cholecystokinin, dynorphin and beta-endorphin in the NIL, whereas the dynorphin content in the AL increased, when values were expressed on a per-lobe basis. On a per-milligram-protein basis, however, only beta-endorphin in the NIL showed a significant decrease, while AL beta-endorphin and dynorphin were increased. Correlated with these changes were a drastic decrease in the serum insulin level and a marked increase in serum glucose and corticosterone levels. All these changes were reversible with insulin treatment. It is suggested that the decrease in NIL contents of neuropeptides demonstrated (except for beta-endorphin) might be due to mechanisms other than a change in synthesis.
研究了链脲佐菌素诱导的糖尿病对垂体神经肽的影响。在成年雄性大鼠接受链脲佐菌素治疗4周后，测量了垂体两叶中的P物质、强啡肽和β-内啡肽以及神经中间叶（NIL）中的胆囊收缩素和生长抑素。以前叶（AL）和NIL中每叶为单位表示时，前叶和NIL中的P物质水平以及NIL中的胆囊收缩素、强啡肽和β-内啡肽均显著降低，而前叶中的强啡肽含量增加。然而，以每毫克蛋白质为单位时，仅NIL中的β-内啡肽显著降低，而前叶中的β-内啡肽和强啡肽增加。与这些变化相关的是血清胰岛素水平急剧下降以及血清葡萄糖和皮质酮水平显著升高。所有这些变化均可通过胰岛素治疗逆转。有人提出，所显示的神经中间叶中神经肽含量的降低（β-内啡肽除外）可能是由于合成变化以外的机制所致。
