Rice G E, Jenkin G, Thorburn G D
J Endocrinol. 1986 Jan;108(1):109-16. doi: 10.1677/joe.0.1080109.
The subcellular distribution of progesterone and oxytocin within the ovine corpus luteum was investigated using differential and density gradient centrifugation. Progesterone and oxytocin were associated with particles which sedimented to a density of 1.049-1.054 g/ml and 1.054-1.061 g/ml respectively. Particle-associated progesterone did not, however, display physical or biochemical characteristics consistent with its storage within secretory granules. When particle-associated progesterone was incubated in HEPES buffer at 37 degrees C, 70% of the total progesterone was recovered in the incubation medium. The remaining stable particle-associated progesterone was not affected by treatments which stimulated oxytocin release and which have been shown to cause the release of peptides and biogenic amines from secretory granules. These results suggest that particle-associated progesterone represents the intercalation of progesterone into cell membranes and they do not support the hypothesis that progesterone is stored, in a protein-bound form, in luteal secretory granules.
采用差速离心和密度梯度离心法研究了孕酮和催产素在绵羊黄体中的亚细胞分布。孕酮和催产素分别与沉降至密度为1.049 - 1.054 g/ml和1.054 - 1.061 g/ml的颗粒相关。然而，与颗粒结合的孕酮并未表现出与其储存于分泌颗粒内相一致的物理或生化特性。当与颗粒结合的孕酮在37℃的HEPES缓冲液中孵育时，70%的总孕酮在孵育介质中被回收。其余稳定的与颗粒结合的孕酮不受刺激催产素释放的处理影响，且这些处理已被证明会导致肽和生物胺从分泌颗粒中释放。这些结果表明，与颗粒结合的孕酮代表孕酮插入细胞膜，并且不支持孕酮以蛋白质结合形式储存于黄体分泌颗粒中的假说。
