Alam T, Chen L, Ogawa A, Leffert J D, Unger R H, Luskey K L
Gifford Laboratories, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas.
Diabetes. 1992 Apr;41(4):508-14. doi: 10.2337/diab.41.4.508.
Amylin is a 37-amino acid peptide synthesized in the pancreatic beta-cell and cosecreted with insulin. In situ hybridization of nondiabetic rat pancreas shows that insulin and amylin RNA are both localized within the islet of Langerhans in a similar distribution. After 12 days of insulin-induced hypoglycemia (mean blood glucose 3.0 +/- 0.4 mM [54 +/- 8 mg/dl]), both insulin and amylin RNA fell greater than 95%. However, maintenance of euglycemia by simultaneous infusion of glucose with insulin did not suppress insulin or amylin RNA. Fasting suppressed amylin and insulin secretion from the isolated, perfused pancreas 70 and 58%, respectively, and with refeeding, secretion rates recovered to fed levels. Despite these changes in the rates of secretion, the relative ratio of amylin to insulin was not significantly different in fed, fasted, or refed rats. The molar ratio of insulin to amylin was estimated to be 100:2.3-2.6. Both insulin and amylin RNA was suppressed approximately 50% in response to fasting. Thus, although the absolute amounts of insulin and amylin change substantially under the conditions tested, the relative amounts of these peptides do not change.
胰淀素是一种由胰腺β细胞合成并与胰岛素共同分泌的含37个氨基酸的肽。非糖尿病大鼠胰腺的原位杂交显示，胰岛素和胰淀素RNA在朗格汉斯岛内的分布相似。在胰岛素诱导的低血糖12天后（平均血糖3.0±0.4 mM [54±8 mg/dl]），胰岛素和胰淀素RNA均下降超过95%。然而，通过同时输注葡萄糖与胰岛素维持血糖正常并未抑制胰岛素或胰淀素RNA。禁食分别抑制了离体灌注胰腺中胰淀素和胰岛素分泌的70%和58%，再喂食后，分泌率恢复到喂食水平。尽管分泌率有这些变化，但在喂食、禁食或再喂食的大鼠中，胰淀素与胰岛素的相对比例并无显著差异。胰岛素与胰淀素的摩尔比估计为100:2.3 - 2.6。禁食后，胰岛素和胰淀素RNA均被抑制约50%。因此，尽管在测试条件下胰岛素和胰淀素的绝对量有很大变化，但这些肽的相对量并未改变。
