Tobin A B, Osborne N N
Nuffield Laboratory of Ophthalmology, Oxford, England.
J Neurochem. 1989 Sep;53(3):686-91. doi: 10.1111/j.1471-4159.1989.tb11758.x.
Serotonin has no obvious effect on basal cyclic AMP levels but reduces the forskolin-, isoproterenol-, and vasoactive intestinal peptide-induced stimulation of cyclic AMP levels in a dose-dependent manner. Serotonergic, cholinergic, muscarinic, alpha-adrenergic, and dopaminergic antagonists have no effect on the serotonin response. Topical application of a serotonin/pargyline solution to the living eye causes desensitisation of the serotonin response in the iris-ciliary body, an observation confirming the presence of specific serotonergic receptors linked to adenylate cyclase. The 5-HT1A [5-hydroxytryptamine (serotonin) type 1A] receptor agonists 8-hydroxy-2-(di-n-propylamino)tetralin and buspirone mimic the serotonin response in reducing the forskolin-stimulated cyclic AMP levels, as do the indole derivatives 5-methoxytryptamine, 5-hydroxtryptophan, and tryptamine. However, the ineffectiveness of the 5-HT1A agonist ipsapirone and the inability of spiroxatrine to block the serotonin response show that classical 5-HT1A receptors are not involved. The serotonin response is blocked by pertussis toxin and is insensitive to the phosphodiesterase inhibitor theophylline, which indicates the involvement of an inhibitory guanine regulatory protein in the coupling of the serotonin receptor to the adenylate cyclase catalytic unit.
血清素对基础环磷酸腺苷水平无明显影响，但能以剂量依赖的方式降低福斯高林、异丙肾上腺素和血管活性肠肽诱导的环磷酸腺苷水平升高。血清素能、胆碱能、毒蕈碱能、α-肾上腺素能和多巴胺能拮抗剂对血清素反应均无影响。将血清素/帕吉林溶液局部应用于活体眼睛可导致虹膜睫状体中血清素反应脱敏，这一观察结果证实了存在与腺苷酸环化酶相连的特异性血清素能受体。5-HT1A[5-羟色胺（血清素）1A型]受体激动剂8-羟基-2-（二正丙基氨基）四氢萘和丁螺环酮在降低福斯高林刺激的环磷酸腺苷水平方面模拟了血清素反应，吲哚衍生物5-甲氧基色胺、5-羟色氨酸和色胺也是如此。然而，5-HT1A激动剂伊沙匹隆无效，螺沙屈林无法阻断血清素反应，这表明经典的5-HT1A受体不参与其中。血清素反应可被百日咳毒素阻断，且对磷酸二酯酶抑制剂茶碱不敏感，这表明抑制性鸟嘌呤调节蛋白参与了血清素受体与腺苷酸环化酶催化单位的偶联。
