Department of Zoology, Center for Advanced Study, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India.
Gen Comp Endocrinol. 2010 Mar 1;166(1):111-6. doi: 10.1016/j.ygcen.2009.11.016. Epub 2009 Dec 11.
In the present study, tyrosine hydroxylase (TH, the rate-limiting enzyme in catecholamine synthesis) activity was demonstrated in the ovary of the catfish to elucidate the possible physiological role of catecholamines in the gonad. The ovary is innervated by seven pairs of nerves, originating from the paired sympathetic chain lying dorsal to the posterior kidney. Ovarian TH activity showed a significant annual variation (P<0.001, one-way ANOVA), correlating with gonado-somatic index. Activity was low from December to February (resting phase), increased from March to July (recrudescent phase) and then decreased in post-spawning phase (August-November). The annual pattern was similar to that of the brain. An intraperitoneal injection of 100 IU hCG/fish induced significant periovulatory changes in TH activity with the peak rise at 16 h, and the activity decreased after egg-stripping (P<0.001, one-way ANOVA). Brain TH activity showed similar periovulatory changes. The results suggest that catecholamine synthesis is increased during both ovarian recrudescence and spawning of the annual reproductive cycle, implying a functional role in ovarian growth, maturation and ovulation.
在本研究中，我们证明了鲶鱼卵巢中酪氨酸羟化酶（TH，儿茶酚胺合成的限速酶）的活性，以阐明儿茶酚胺在性腺中的可能生理作用。卵巢由七对神经支配，这些神经起源于位于后肾上方的成对交感神经链。卵巢 TH 活性表现出显著的年度变化（P<0.001，单因素方差分析），与性腺体指数相关。从 12 月到 2 月（休眠期）活性较低，从 3 月到 7 月（复苏期）增加，然后在产卵后阶段（8 月至 11 月）下降。该年度模式与大脑相似。100 IU hCG/鱼的腹腔注射诱导 TH 活性发生显著的排卵前变化，峰值出现在 16 小时，排卵后活性下降（P<0.001，单因素方差分析）。大脑 TH 活性也表现出类似的排卵前变化。结果表明，儿茶酚胺合成在卵巢复苏和年度生殖周期的产卵过程中增加，这意味着在卵巢生长、成熟和排卵过程中具有功能作用。
