Joy K P, Agha A K
Department of Zoology, Banaras Hindu University Varanasi, India.
J Pineal Res. 1989;7(3):281-9. doi: 10.1111/j.1600-079x.1989.tb00451.x.
Pinealectomy of Heteropneustes fossilis held under normal photoperiod and ambient temperature produced season-dependent effects on ovarian activity. When the fish were pinealectomized in the preparatory phase (early light-responsive period) and maintained until the early prespawning phase, there was an accelerated growth of the ovary, as adjudged from increased gonado-somatic index (GSI), ovarian histology, elevated ovarian total protein and ascorbic acid levels, and an increased level of serum alkali-labile protein phosphorus (vitellogenin). Pinealectomy was ineffective in the prespawning and spawning (late light-responsive phase) and postspawning (light refractory) phases. The results suggest that the pineal exerts an inhibitory effect on the hypothalamo-hypophysial-ovarian axis and synchronizes temporally ovarian activity in response to increasing photothermal conditions such that spawning takes place at a time most suitable for the survival of the young.
在正常光周期和环境温度下饲养的印度胡鲶进行松果体切除，对卵巢活动产生了季节依赖性影响。当鱼在准备阶段（早期光反应期）进行松果体切除并维持到产卵前期早期时，从性腺-体指数（GSI）增加、卵巢组织学、卵巢总蛋白和抗坏血酸水平升高以及血清碱不稳定蛋白磷（卵黄蛋白原）水平增加判断，卵巢生长加速。松果体切除在产卵前和产卵期（晚期光反应期）以及产卵后（光不应期）无效。结果表明，松果体对下丘脑-垂体-卵巢轴发挥抑制作用，并根据光热条件的增加在时间上同步卵巢活动，从而使产卵发生在最适合幼鱼生存的时间。
