Duke University Marine Laboratory, 28516, Beaufort, North Carolina.
J Chem Ecol. 1991 Jul;17(7):1363-70. doi: 10.1007/BF00983769.
The vertebrate hormone deoxycorticosterone is the most commonly occurring component of defensive secretions from aquatic beetles in the family Dytiscidae. Deoxycorticosterone and the structurally related steroids pregn-4-en-20α:-ol-3-one and pregn-4-en-20β-ol-3-one were tested for their ability to inhibit feeding by bluegill sunfish,Lepomis macrochirus, in laboratory assays. Deoxycorticosterone at oral doses of 660μg (2 x 10(-6) mol) per pellet caused 94% inhibition in the acceptance of artificial food pellets. At the same molar dosage, pregn-4-en-20α-ol-3-one inhibited food consumption by 58%, while its epimer, pregn-4-en-20β-ol-3-one, did not significantly inhibit feeding. These results indicate that specific stereochemical conditions must be satisfied for the pregnenes to be noxious toL. macrochirus and suggest the existence of a receptor-ligand interaction. The potency of the three steroids in assays of feeding inhibition contradicts earlier results based on toxicity and anesthetic assays in which fish were immersed in solutions of steroids.
脊椎动物激素脱氧皮质酮是水生甲虫科水龟甲虫防御分泌物中最常见的成分。在实验室检测中，我们测试了脱氧皮质酮和结构上相关的类固醇孕甾-4-烯-20α-醇-3-酮和孕甾-4-烯-20β-醇-3-酮抑制蓝鳃太阳鱼（蓝鳃太阳鱼）摄食的能力。每丸 660μg（2 x 10(-6) mol）的脱氧皮质酮口服剂量导致人工食物丸的接受率降低 94%。在相同的摩尔剂量下，孕甾-4-烯-20α-醇-3-酮抑制了 58%的摄食，而其差向异构体孕甾-4-烯-20β-醇-3-酮则没有显著抑制摄食。这些结果表明，为了使孕烯对蓝鳃太阳鱼有害，必须满足特定的立体化学条件，并表明存在受体-配体相互作用。这三种类固醇在抑制摄食试验中的效力与基于毒性和麻醉试验的早期结果相矛盾，在这些试验中，鱼被浸泡在类固醇溶液中。
