Dehaye J P, Winand J, Damien C, Gomez F, Poloczek P, Robberecht P, Vandermeers A, Vandermeers-Piret M C, Stiévenart M, Christophe J
Am J Physiol. 1986 Nov;251(5 Pt 1):G602-10. doi: 10.1152/ajpgi.1986.251.5.G602.
Helodermin is a new peptide isolated from the venom of Heloderma suspectum. Its effects on rat pancreatic acini were compared with those of secretin and vasoactive intestinal peptide (VIP). Four classes of receptors with decreasing affinity for secretin (S1, S2, S3, and S4) were first delineated. Occupancy of S1 and S2 by secretin was responsible for a biphasic adenosine 3',5'-cyclic monophosphate (cAMP) response. S3 was VIP preferring so that the VIP-induced increase in cAMP could be inhibited by VIP-(10-28). S2 and S3 allowed cAMP elevation, protein phosphorylation, weak secretory effects, and potentiation of cholecystokinin octapeptide (CCK-8) when occupied by secretin and VIP, respectively. A more efficient exocytosis was observed with secretin interacting with low-affinity receptors S4. Helodermin increased cAMP levels 14-fold, this increase being inhibited by VIP-(10-28). Low concentrations of helodermin stimulated amylase secretion twofold and potentiated secretion by CCK-8. High concentrations of helodermin stimulated secretion another 2.6-fold. Helodermin bound to the four secretin receptors with a weak selectivity. At low concentration, helodermin stimulated cAMP elevation, protein phosphorylation, amylase release, and potentiation of CCK-8 through S3, whereas at high concentration it stimulated secretion via S4.
蝎毒素是从可疑毒蜥毒液中分离出的一种新肽。将其对大鼠胰腺腺泡的作用与促胰液素和血管活性肠肽（VIP）的作用进行了比较。首先确定了对促胰液素亲和力递减的四类受体（S1、S2、S3和S4）。促胰液素占据S1和S2会导致双相3',5'-环磷酸腺苷（cAMP）反应。S3更倾向于结合VIP，因此VIP诱导的cAMP升高可被VIP-(10-28)抑制。当分别被促胰液素和VIP占据时，S2和S3会使cAMP升高、蛋白质磷酸化、产生微弱的分泌作用并增强八肽胆囊收缩素（CCK-8）的作用。促胰液素与低亲和力受体S4相互作用时观察到更有效的胞吐作用。蝎毒素使cAMP水平升高14倍，这种升高被VIP-(10-28)抑制。低浓度的蝎毒素使淀粉酶分泌增加两倍，并增强CCK-8的分泌作用。高浓度的蝎毒素使分泌作用再增加2.6倍。蝎毒素以较弱的选择性与四种促胰液素受体结合。在低浓度时，蝎毒素通过S3刺激cAMP升高、蛋白质磷酸化、淀粉酶释放和增强CCK-8的作用，而在高浓度时，它通过S4刺激分泌。
