Mattson M P, Spaziani E
Gen Comp Endocrinol. 1986 Jun;62(3):419-27. doi: 10.1016/0016-6480(86)90052-3.
Eyestalk-intact, but not de-eyestalked, crabs (Cancer antennarius) given five injections of 5-hydroxytryptamine (5HT, 750 micrograms per injection) in 48 hr showed significant reductions in hemolymph ecdysteroid titers within the first 12 hr which continued through Hour 72; the effect was reversible (Hours 72-144). The 5HT synthesis inhibitor p-chlorophenylalanine (PCPA; 60 micrograms) or the 5HT receptor antagonist cyproheptadine (CPH; 100 micrograms) caused significant rises in serum ecdysteroids in intact, but not in de-eyestalked, crabs; with four injections over 48 hr, a rise was evident at 12 hr, continued through 72 hr, and returned to control levels within 4 days post-treatment. Stress due to handling depressed ecdysteroid levels, an effect that was reversed by PCPA and CPH; values in the treated groups returned to prestress levels within 24 hr and were significantly greater than prestress levels within 48 hr. 5HT treatment did not further decrease stress-reduced ecdysteroid titers. Normal behaviors are described in posturing and in defensive responses to stress; these were changed in both intact and de-eyestalked crabs by 5HT treatment (but not by PCPA or CPH). These findings support the hypothesis that release of molt-inhibiting hormone (MIH) from crab eyestalks is mediated by 5HT and suggest that stress induces 5HT-mediated MIH release.
在48小时内接受5次5-羟色胺（5HT，每次注射750微克）注射的眼柄完整（而非去眼柄）的螃蟹（美洲黄道蟹），在最初12小时内血淋巴蜕皮甾体滴度显著降低，这种降低持续到72小时；该效应是可逆的（72 - 144小时）。5HT合成抑制剂对氯苯丙氨酸（PCPA；60微克）或5HT受体拮抗剂赛庚啶（CPH；100微克）会使完整螃蟹（而非去眼柄螃蟹）的血清蜕皮甾体显著升高；在48小时内进行4次注射后，12小时时升高明显，持续到72小时，并在治疗后4天内恢复到对照水平。处理引起的应激会降低蜕皮甾体水平，PCPA和CPH可逆转这种效应；处理组的值在24小时内恢复到应激前水平，并且在48小时内显著高于应激前水平。5HT处理并未进一步降低因应激而降低的蜕皮甾体滴度。文中描述了螃蟹在姿势和对应激的防御反应方面的正常行为；5HT处理（而非PCPA或CPH）使完整和去眼柄的螃蟹的这些行为都发生了改变。这些发现支持了这样的假说，即螃蟹眼柄中蜕皮抑制激素（MIH）的释放是由5HT介导的，并表明应激会诱导5HT介导的MIH释放。
