Gause I, Edén S, Isaksson O, DiGirolamo M, Smith U
Acta Physiol Scand. 1985 Jun;124(2):229-38. doi: 10.1111/j.1748-1716.1985.tb07656.x.
Growth hormone (GH) binding and the effect of GH and insulin on glucose metabolism in rat adipocytes were studied at various time periods following hypophysectomy. Male rats were hypophysectomized at 33-34 days of age. After 6 h, 20 h or 3, 7 and 14 days adipocytes were prepared from epididymal fat pads by mild collagenase digestion (0.5 mg X ml-1, 60 min, 37 degrees C). Glucose metabolism was studied by determining the production of CO2 from [14C]glucose and the incorporation of [14C]glucose into lipids. GH binding was measured in cell aliquots using [125I]hGH. No difference in GH binding to adipocytes was observed between control rats and rats hypophysectomized or sham-operated 6 h earlier. GH binding was significantly decreased 20 h after hypophysectomy and declined further with time after hypophysectomy. Adipose tissue from normal rats is usually refractory to the insulin-like effect of GH. Adipocytes isolated from normal rats were, however, usually responsive to GH immediately after cell isolation, suggesting that refractoriness to the insulin-like effect of GH was lost during the time required for the preparation of adipocytes. The magnitude of the response to GH in adipocytes progressively declined with time after hypophysectomy. The decreased responsiveness to GH with time after hypophysectomy parallelled the decrease in GH binding. The results suggest that the pituitary, directly or indirectly, is necessary for the maintenance of GH binding sites in adipose tissue and that these binding sites are related to the insulin-like effect of GH.
在垂体切除术后的不同时间段，研究了生长激素（GH）结合以及GH和胰岛素对大鼠脂肪细胞葡萄糖代谢的影响。雄性大鼠在33 - 34日龄时接受垂体切除术。6小时、20小时或3天、7天和14天后，通过温和的胶原酶消化（0.5mg/ml，60分钟，37℃）从附睾脂肪垫制备脂肪细胞。通过测定[14C]葡萄糖产生的CO2以及[14C]葡萄糖掺入脂质中来研究葡萄糖代谢。使用[125I]hGH在细胞等分试样中测量GH结合。在对照大鼠与提前6小时接受垂体切除术或假手术的大鼠之间，未观察到GH与脂肪细胞结合的差异。垂体切除术后20小时，GH结合显著降低，并且在垂体切除术后随时间进一步下降。正常大鼠的脂肪组织通常对GH的胰岛素样作用不敏感。然而，从正常大鼠分离的脂肪细胞在细胞分离后通常立即对GH有反应，这表明在制备脂肪细胞所需的时间内，对GH胰岛素样作用的不敏感性丧失了。垂体切除术后，脂肪细胞对GH的反应程度随时间逐渐下降。垂体切除术后随时间对GH反应性的降低与GH结合的降低平行。结果表明，垂体直接或间接对于维持脂肪组织中GH结合位点是必要的，并且这些结合位点与GH的胰岛素样作用有关。
