Adenosine cyclic 3',5'-monophosphate in the liver fluke, Fasciola hepatica. I. Activation of adenylate cyclase by 5-hydroxytryptamine.
Adenosine cyclic 3',5'-monophosphate in the liver fluke, Fasciola hepatica. I. Activation of adenylate cyclase by 5-hydroxytryptamine.
复制标题
肝吸虫、肝片形吸虫中的环 3,5-单磷酸腺苷。
作者：
S. L. Abrahams;J. Northup;T. Mansour
5-羟色胺引起肝片吸虫体内内源性环39,59-单磷酸腺苷的显著积累，特别是在肝片吸虫的前端（“头部”）。环核苷酸的积累和伴随的吸虫头运动性的增加依赖于5-羟色胺浓度。来自吸虫头部的颗粒中的腺苷酸环化酶也显示出比来自吸虫尾部的颗粒更大的5-羟色胺激活。5-羟色胺的吲哚胺类似物刺激吸虫运动和激活腺苷酸环化酶的能力随着其与5-羟色胺类似物结构相似性的降低而减弱。5-羟色胺的游离氨基和5-羟基似乎对腺苷酸环化酶的识别都很重要。这些结果支持了腺苷环39,59-单磷酸在无脊椎动物中作为5-羟色胺的第二信使的假设。另一方面，这项研究表明环核苷酸的升高和运动性的刺激之间没有直接的关系。安非他明和d -麦角酸二乙胺都刺激了吸虫的运动，但没有引起内源性环核苷酸水平的增加。此外，d -麦角酸二乙胺对腺苷酸环化酶的5-羟色胺活化具有拮抗作用。结果表明，这种拮抗作用可能与d -麦角酸二乙胺对其腺苷酸环化酶位点的高亲和力有关。
5-Hydroxytryptamine caused a marked accumulation of endogenous adenosine cyclic 39,59-monophosphate in the liver fluke, Fasciola hepatica, especially in the anterior end ("head") of the organism. The accumulation of the cyclic nucleotide and the accompanying increase in motility of the isolated fluke head were dependent on 5-hydroxytryptamine concentration. Adenylate cyclase in particles from fluke heads also showed a greater activation by 5-hydroxytryptamine than did particles from the posterior end of the fluke. The ability of indoleamine analogues of 5-hydroxytryptamine to stimulate fluke motility and to activate adenylate cyclase was found to diminish with decreasing structural similarity of the analogue to 5-hydroxytryptamine. Both the free amino and 5-hydroxyl groups of 5-hydroxytryptamine appear to be important for its recognition by adenylate cyclase. The results support the hypothesis that adenosine cyclic 39,59-monophosphate acts as a second messenger for 5-hydroxytryptamine in invertebrates. On the other hand, this investigation suggests no direct relationship between the elevation of the cyclic nucleotide and the stimulation of motility. Both amphetamine and D-lysergic acid diethylamide stimulated fluke motility but did not cause an increase in endogenous levels of the cyclic nucleotide. Moreover, D-lysergic acid diethylamide antagonized the 5-hydroxytryptamine activation of adenylate cyclase. The results suggest that this antagonism may be related to the high affinity of D-lysergic acid diethylamide for its site on adenylate cyclase.