Matozaki T, Sakamoto C, Nagao M, Baba S
Nihon Naibunpi Gakkai Zasshi. 1986 Dec 20;62(12):1376-83. doi: 10.1507/endocrine1927.62.12_1376.
The effects of pretreatment with pancreatic secretagogues and subsequently activated cellular events on [125I-Tyr1] somatostatin binding to acinar membranes were studied. Pretreatment of pancreatic acini with bombesin at increasing concentrations for 120 min reduced labeled somatostatin binding to the acinar membranes in a dose-dependent fashion with a maximal reduction of binding at 10(-8)M bombesin (44.3 +/- 1.8% of control). The maximal inhibition of labeled somatostatin binding by pretreatment with bombesin was almost comparable to that with COOH-terminal octapeptide cholecystokinin (CCK8) or carbamylcholine (carbachol). Furthermore, pretreatment of acini with vasoactive intestinal peptide (VIP) as well as secretin resulted in a small, but significant decrease of subsequent labeled somatostatin binding. In addition, adenosine 3', 5' cyclic nucleotide derivatives or a phosphodiesterase inhibitor mimicked the effect of VIP or secretin. The effect of simultaneous pretreatment of acini with VIP and carbachol on subsequent labeled somatostatin binding appeared to be almost equal to the calculated additive value for each peptide. These results suggest that the binding of somatostatin to its receptors in the pancreatic acini may be regulated via two functionally distinct pathways.
研究了用胰腺促分泌剂预处理以及随后激活的细胞事件对[125I-酪氨酸1]生长抑素与腺泡膜结合的影响。用不同浓度的蛙皮素预处理胰腺腺泡120分钟，可使标记的生长抑素与腺泡膜的结合呈剂量依赖性降低，在10(-8)M蛙皮素时结合减少最大（为对照的44.3±1.8%）。用蛙皮素预处理对标记生长抑素结合的最大抑制作用几乎与用羧基末端八肽胆囊收缩素（CCK8）或氨甲酰胆碱（卡巴胆碱）的抑制作用相当。此外，用血管活性肠肽（VIP）以及促胰液素预处理腺泡，会导致随后标记的生长抑素结合略有但显著减少。另外，腺苷3',5'-环核苷酸衍生物或磷酸二酯酶抑制剂模拟了VIP或促胰液素的作用。同时用VIP和卡巴胆碱预处理腺泡对随后标记的生长抑素结合的影响似乎几乎等于每种肽的计算相加值。这些结果表明，生长抑素与其在胰腺腺泡中的受体的结合可能通过两条功能不同的途径进行调节。
