Pituitary-dependent expression of the testicular angiotensin II receptor and its subtypes in rats

• Published in: International journal of andrology 1998-08, Vol.21 (4), p.177-185
• Main Authors: HIRAI, K, SONG, K, KANEHARA, H, SHIOTA, N, UEDA, H, KIM, S, MIYAZAKI, H, KATSUOKA, Y, MIYAZAKI, M
• Format: Article
• Language: English
• Subjects: Angiotensin II - metabolism; angiotensin II receptor; Animals; Biological and medical sciences; Body Weight; Fundamental and applied biological sciences. Psychology; Gene Expression; Humans; Hypophysectomy; in vitro autoradiography; Male; Mammalian male genital system; Morphology. Physiology; Organ Size; Pituitary Gland - physiology; Rats; Rats, Sprague-Dawley; receptor subtypes; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, Angiotensin - genetics; Receptors, Angiotensin - metabolism; RNA, Messenger; testis; Testis - metabolism; Vertebrates: reproduction
• ISSN: 0105-6263; 1365-2605
• DOI: 10.1046/j.1365-2605.1998.00102.x

Angiotensin II (AT2) has been implicated in the growth and/or differentiation of its target tissues. In the present study, testicular AT2 receptor and its subtypes in hypophysectomized rats were examined using quantitative in vitro autoradiography and Northern blot analysis in an attempt to determine possible involvement of pituitary hormones in their expression. Prepubescent (3 weeks of age) male Sprague–Dawley rats underwent hypophysectomy or sham operation. From 10 days thereafter, they were treated with vehicle, growth hormone, human chorionic gonadotrophin or human menopausal gonadotrophin for 10 days. Testicular AT2 receptors were labelled with 125I‐[Sar1,Ile8] AT2 and differentiated into its subtypes (AT1 and FAT2) according to their susceptibility to AT1 (losartan, 5 μM) and AT2 (CGP42112B, 1 μM) antagonists. Hypophysectomy led to a marked increase in AT2 receptor concentration (sham‐operated rats: 0.7 ± 0.2 fmol/mg protein, hypophysectomized rats: 2.5 ± 0.6 fmol/mg protein, mean ± SEM, n = 11–12, p