Department of Animal Physiology, Bose Institute, P-1/12 CIT, Scheme VII M, Calcutta, 700054, India.
Fish Physiol Biochem. 2006 Mar;32(1):73-81. doi: 10.1007/s10695-006-7657-0.
Triploid Heteropneustes fossilis (Bloch) showed sterility and higher growth potential than the normal diploid fish. Activities of some metabolic enzymes such as cytosolic NADP-malate dehydrogenase (NADP-MDH), mitochondrial NAD-malate dehydrogenase (NAD-MDH) and glutamate pyruvate transaminase (GPT) were evaluated in liver, brain and kidney along with glucose-6-phosphate dehydrogenase (G-6-P D) in ovary of female triploid catfish. Activities of these enzymes showed distinct seasonal periodicity, mostly with highest activities in prespawning and spawning periods, in both diploid and triploid catfish but differed in magnitude. In triploid liver, GPT showed higher activity than the diploid counterpart in prespawning and spawning periods. On the contrary, mitochondrial NAD-MDH and cytosolic NADP-MDH in this organ showed a consistent lower activity than the diploid in all stages or in some stages of reproductive cycle respectively. Interestingly, none of the enzymes in brain and kidney of triploid female catfish showed significant changes in comparison to the diploid counterpart. The triploid ovary maintained a significantly lower level of G-6-P D activity throughout the resting, preparatory and pre-spawning periods compared to the diploid ovary. Lower level of malic enzymes (NAD-MDH and NADP-MDH) in liver and G-6-P D in ovary are in close synchrony with lower level of estradiol-17beta in plasma of female triploids as found in earlier study.
三倍体中华鲟（Bloch）表现出不育性和更高的生长潜力，优于正常的二倍体鱼类。在雌性三倍体鲇鱼的卵巢中，评估了肝脏、大脑和肾脏中一些代谢酶的活性，如细胞质 NADP-苹果酸脱氢酶（NADP-MDH）、线粒体 NAD-苹果酸脱氢酶（NAD-MDH）和谷氨酸丙酮酸转氨酶（GPT），以及葡萄糖-6-磷酸脱氢酶（G-6-P D）。这些酶的活性表现出明显的季节性周期性，大多数在产卵前和产卵期达到最高活性，无论是二倍体还是三倍体鲇鱼都是如此，但活性大小不同。在三倍体肝脏中，GPT 在产卵前和产卵期的活性高于二倍体。相反，该器官中的线粒体 NAD-MDH 和细胞质 NADP-MDH 的活性在所有阶段或生殖周期的某些阶段均低于二倍体。有趣的是，三倍体雌性鲇鱼的大脑和肾脏中的任何一种酶与二倍体相比均未显示出显著变化。三倍体卵巢在整个休眠期、准备期和产卵前期的 G-6-P D 活性均显著低于二倍体卵巢。在早期研究中发现，与二倍体相比，三倍体中华鲟肝脏中的苹果酸酶（NAD-MDH 和 NADP-MDH）和卵巢中的 G-6-P D 水平较低，与血浆中雌二醇-17β水平较低密切相关。
