Day R, Dong W, Panetta R, Kraicer J, Greenwood M T, Patel Y C
Fraser Laboratories, Department of Medicine, McGill University, Royal Victoria Hospital, Montreal, Quebec, Canada.
Endocrinology. 1995 Nov;136(11):5232-5. doi: 10.1210/endo.136.11.7588263.
To characterize cell specific expression of sstr subtypes in the pituitary we have analyzed mRNA for sstr1-5 in rat pituitary somatotrophs by reverse transcriptase polymerase chain reaction and determined the pattern and level of expression of mRNA for sstr subtypes 2 and 5 in individual pituitary cell subpopulations by double label in situ hybridization. Purified somatotrophs expressed mRNA for all 5 sstrs. In situ hybridization analysis revealed sstr5 mRNA in 70% of somatotrophs, 57% of thyrotrophs, 38% of corticotrophs, 33% of lactotrophs, and 21% of gonadotrophs. mRNA for sstr2 occurred in 40% of somatotrophs, 36% of thyrotrophs, 26% of lactotrophs, 3% of corticotrophs, and 8% of gonadotrophs. Not only were more cells positive for sstr5 mRNA but the average number of autoradiographic grains/cell was also higher for sstr5 than sstr2. These results show expression of multiple sstr genes in individual pituitary cells. mRNA for sstr2 and 5 occur in each of the 5 major pituitary cell subsets, sstr5 mRNA being more widely and more abundantly expressed than sstr2.
为了表征垂体中生长抑素受体（sstr）亚型的细胞特异性表达，我们通过逆转录聚合酶链反应分析了大鼠垂体生长激素细胞中sstr1 - 5的mRNA，并通过双标记原位杂交确定了单个垂体细胞亚群中sstr2和5亚型mRNA的表达模式和水平。纯化的生长激素细胞表达了所有5种sstr的mRNA。原位杂交分析显示，70%的生长激素细胞、57%的促甲状腺激素细胞、38%的促肾上腺皮质激素细胞、33%的催乳激素细胞和21%的促性腺激素细胞中有sstr5 mRNA。sstr2的mRNA出现在40%的生长激素细胞、36%的促甲状腺激素细胞、26%的催乳激素细胞、3%的促肾上腺皮质激素细胞和8%的促性腺激素细胞中。不仅sstr5 mRNA阳性的细胞更多，而且sstr5每个细胞的放射自显影片颗粒平均数也高于sstr2。这些结果表明单个垂体细胞中多种sstr基因的表达。sstr2和5的mRNA出现在垂体5个主要细胞亚群的每一个中，sstr5 mRNA的表达比sstr2更广泛、更丰富。
