Thee effect of 5-HTP on the reproductive timer in the male cricket.
The post-copulatory sexually refractory stage in the male cricket Gryllus bimaculatus consists of the two substages: the first refractory stage (RS1, time-variable) between copulation and spermatophore preparation, and the second refractory stage (RS2, time-constant) between spermatophore preparation and the recommencement of courtship. To understand the mechanism of the timer for RS2, subcuticular or intraganglionic injection of biogenic amines (10(-2) mol l(-1)) was performed immediately after spermatophore preparation. RS2 was shortened by octopamine, 5-HT, 5-HTP and NA-5-HT. Among these, 5-HTP was most potent. It shortened RS2 to maximally about 38% of the control. The shortening effect continued for 4.5 h after subcuticular injection even when the hemolymph was washed out with saline at 1 hour after injection. Simultaneous injection of 5-HTP with the inhibitor (NSD-1015) of 5-HT synthesis enzyme nullified the effect of 5-HTP, indicating that the shortening effect was caused by 5-HT synthesized from extrinsic 5-HTP. Injection of the inhibitor (CHX) of protein synthesis had no effect of on RS2. These results suggest that the reproductive timer in the TAG may be controlled by 5-HT or a second messenger mediated by 5-HT.
Department of Biology, Faculty of Science, Okayama University, Tsushima-Naka-3-1-1, Okayama, 700-8530, Japan. masack@cc.okayama-u.ac.jp
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D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal; D003307:Copulation; D003513:Cycloheximide / Q000494:pharmacology; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D006135:Gryllidae; D006458:Hemolymph / Q000378:metabolism; D008297:Male; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012098:Reproduction / Q000187:drug effects*; D012701:Serotonin / Q000378:metabolism; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D013093:Spermatogonia / Q000187:drug effects / Q000502:physiology*; D013696:Temperature; D013997:Time Factors
D016166:Free Radical Scavengers; D011500:Protein Synthesis Inhibitors; D012701:Serotonin; D003513:Cycloheximide; D006916:5-Hydroxytryptophan