High plasma steroid levels in the squirrel monkey: deficient receptors or metabolism?
High plasma steroid levels in the squirrel monkey: deficient receptors or metabolism?
复制标题
松鼠猴血浆类固醇水平高：受体或代谢缺陷？
DOI：
10.1007/978-1-4684-5101-6_18
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发表时间：
1986
影响因子：
--
通讯作者：
Siiteri,PK
中科院分区：
文献类型：
--
作者：
Siiteri,PK
与人类和东半球灵长类动物相比，许多新大陆灵长类动物，如松鼠猴，其血浆类固醇激素水平非常高。为了阐明这种明显的类固醇抵抗的机制(S)，研究了几个物种的生殖器皮肤成纤维细胞中糖皮质激素和雄激素与可能的受体结合的情况。在亲和力和/或结合部位的数量上发现了差异，但与东半球和新大陆灵长类物种之间血浆总类固醇或游离类固醇浓度的巨大差异相比，这些差异很小。相反，当比较成纤维细胞代谢睾酮的能力时，松鼠猴细胞缺乏5α-还原酶活性，而这在人类细胞中很容易被证明。再加上其他数据表明，松鼠猴几乎不排泄5-α或5-β减少的尿类固醇代谢物，这些结果表明，松鼠猴血浆激素水平升高可能是代谢效率低下而不是受体结合异常造成的。
Many New World primates such as the squirrel monkey have extraordinarily high plasma steroid hormone levels as compared to humans and Old World primates. To clarify the mechanism(s) underlying this apparent steroid resistance, glucocorticoid and androgen binding to putative receptors in genital skin fibroblasts from several species was investigated. Differences in either affinity and/or number of binding sites were found but these were small compared to the very large differences in total or free plasma steroid concentrations between Old and New World primate species. In contrast, when the ability of fibroblasts to metabolize testosterone was compared, squirrel monkey cells were devoid of 5α-reductase activity which was readily demonstrated in human cells. Together with other data indicating that squirrel monkeys excrete little if any 5α- or 5β-reduced urinary steroid metabolites, these results suggest that inefficient metabolism rather than receptor binding abnormalities may account for the elevated plasma hormone levels in the squirrel monkey.