Endocrinological Study on Phylogeny of Amphibia

1)从蟾蜍脑垂体中分离得到两种糖蛋白，经生物学活性鉴定为促卵泡激素（FSH）和促黄体生成激素（LH）。使用抗血清对这些激素，我们研究了各种脊椎动物的促性腺激素的交叉反应。牛蛙促性腺激素表现出相对较高的交叉反应性，但哺乳动物和鸟类促性腺激素略有。硬骨鱼促性腺激素没有完全交叉反应。2）牛蛙睾丸促性腺激素受体与牛蛙FSH和LH的结合亲和力相同。但在两种激素同时存在下，LH的结合亲和力随FSH浓度的增加而增加。3）LH β-亚基中脯氨酸含量在脊椎动物中变化很大，从6%到20%，而FSH的脯氨酸含量变化很小或几乎不变。两栖类LH β亚基含量最低。脯氨酸残基的位置被认为在整个脊椎动物进化过程中大部分是保守的。

1) We isolated two species of glycoproteins from pituitary glands of the toad, Bufo japonicus, and identified them as follicle stimulating hormone (FSH) and luteinizing hormone (LH) from their biological activities. Using antisera raised against these hormones, we examined cross reactivity of gonadotropins of various vertebrates. Bullfrog gonadotropins showed relatively high crossreactivity, but mammalian and avian gonadotropins did slightly. Teleostean gonadotropins did not cross-react completely.2) The testicular gonadotropin receptor in the bullfrog, Rana catesbeiana, bound both bullfrog FSH and bullfrog LH with the same affinity when they were tested independently. However, under the presence of both hormone, the binding affinity of LH was in creased as a function of the concentration of FSH. This positive cooperative mechanism suppresses partially the competitive inhibition of LH action by FSH.3) The proline content in the beta-subunit of LH varied among classes of vertebrate vigorously, from about 6% to about 20%, while that of FSH was varied in a small range or almost constant. The amphibian LH beta-subunit showed the smallest content. The positions of the proline residues are considered to be mostly conserved throughout the course of the vertebrate evolution.