Cauvin A, Vandermeers-Piret M C, Vandermeers A, Coussaert E, de Neef P, Robberecht P, Christophe J
Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium.
Peptides. 1990 Sep-Oct;11(5):1009-14. doi: 10.1016/0196-9781(90)90025-z.
PHI and the two C-terminally extended forms PHI-GLY and PHV(1-42) coexist in rat tissues. We compared the relative potency and efficacy of these three PHI forms and of VIP to stimulate adenylate cyclase activity and, when feasible, to occupy VIP receptors in six rat tissue and cell membranes. With the exception of lung membranes, all three PHI forms were markedly less potent than VIP but all were systematically as efficacious. PHI-GLY and PHV(1-42) were never more potent than PHI itself and their relative potencies revealed four spectra, depending on the membrane preparation tested: 1) PHI = PHI-GLY = PHV(1-42) in hepatic, pulmonary and pancreatic membranes; 2) PHI greater than PHV(1-42) = PHI-GLY in membranes from circulating lymphocytes; 3) PHI = PHV(1-42) greater than PHI-GLY in membranes from the thymocyte cell line 51E; and 4) PHI greater than PHI-GLY = PHV(1-42) in anterior pituitary membranes. These results indicate that the two naturally observed C-terminal extensions of rat PHI variously affected peptide potency on 6 rat membrane preparations.
PHI以及两种C末端延伸形式PHI-GLY和PHV(1-42)共存于大鼠组织中。我们比较了这三种PHI形式以及VIP刺激腺苷酸环化酶活性的相对效力和效能，并在可行的情况下，比较了它们在六种大鼠组织和细胞膜中占据VIP受体的能力。除肺膜外，所有三种PHI形式的效力均明显低于VIP，但在系统性上它们的效能相同。PHI-GLY和PHV(1-42)的效力从未超过PHI本身，并且它们的相对效力呈现出四种情况，具体取决于所测试的膜制剂：1）在肝、肺和胰细胞膜中，PHI = PHI-GLY = PHV(1-42)；2）在循环淋巴细胞的膜中，PHI大于PHV(1-42) = PHI-GLY；3）在胸腺细胞系51E的膜中，PHI = PHV(1-42)大于PHI-GLY；4）在垂体前叶膜中，PHI大于PHI-GLY = PHV(1-42)。这些结果表明，大鼠PHI天然存在的两种C末端延伸对6种大鼠膜制剂上肽的效力有不同影响。
