GROWTH HORMONE AND DIFFERENTIATION

垂体生长激素（GH）具有促生长和分化作用， 方面的影响. 这些过程之间的关系定义不清。 不 明确它们是否在GH中具有相同的结构决定因素。 我们有一个 无生长促进活性的牛GH片段， 前脂肪细胞向脂肪细胞的分化。 方法已经 开发用于从血清中去除GH和非GH脂肪形成活性。 一 还开发了不含血清的成分确定培养基， 小鼠3 T3前脂肪细胞的脂肪生成和生长，这两种反应都是 对GH敏感。 我们将确定克隆扩增、终末细胞 伴随前脂肪细胞的分裂和激素反应 差异化与差异化有关，或需要额外的 天然GH和/或其他血清因子的影响。 体内促生长 我们的GH片段的活性将在切除垂体的大鼠中测定。 还将研究GH对前脂肪细胞的体外生长促进作用。 具有成脂GH片段和高与低频率分化 前脂肪细胞亚克隆，脂肪形成受体的性质将是 评估。 这些研究将有助于了解 生长激素的作用机制及分化与生长的关系。

Pituitary growth hormone (GH) has growth promoting and differentiating effects. The relationship of these processes is poorly defined. It is not clear whether they have the same structural determinants in GH. We have a bovine GH fragment without growth promoting activity which can promote differentiation of pre-adipocytes to adipocytes. Methods have been developed to remove GH and non-GH adipogenic activity from serum. A defined medium without serum has also been developed to study both in vitro adipogenesis and growth of murine 3T3 pre-adipocytes, both responses being sensitive to GH. We shall determine if clonal expansion, terminal cell division and hormonal responsiveness that accompany pre-adipocyte differentiation are related to differentiation or require additional effects of native GH and/or other serum factors. In vivo growth promoting activity of our GH fragments will be determined in hypophysectomized rats. In vitro growth promotion by GH of pre-adipocytes will also be studied. With an adipogenic GH fragment and high vs. low frequency differentiating preadipocyte sub-clones, the nature of adipogenic receptors will be evaluated. These studies will contribute to an understanding of the mechanism of GH action and the relationship of differentiation and growth.