-transparent.png){kind=logo}
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 microM) and AT2 (CGP42112B, 1 microM) 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 < 0.01) with predominant occurrence of AT1 receptors. Both human chorionic gonadotrophin and human menopausal gonadotrophin decreased testicular AT2 receptor concentration, whereas growth hormone did not affect AT2 receptor expression. Northern blot analysis revealed both testicular AT1 and AT2 receptor mRNA expression to be significantly increased after hypophysectomy and reduced by gonadotrophin treatment. These results suggest that the expression of testicular AT2 receptors is regulated by pituitary gonadotrophins and that AT2 may play a role in testicular growth and/or differentiation.
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
July 2007,
Investigative ophthalmology & visual science,
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
May 1996,
Neuroreport,
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
October 1995,
Molecular and cellular endocrinology,
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
June 1992,
American journal of hypertension,
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
January 1998,
Life sciences,
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
April 2010,
Aging clinical and experimental research,
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
September 2000,
Pediatric nephrology (Berlin, Germany),
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
August 1992,
Trends in endocrinology and metabolism: TEM,
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
June 1998,
The American journal of physiology,
K Hirai, and
K Song, and
H Kanehara, and
N Shiota, and
H Ueda, and
S Kim, and
H Miyazaki, and
Y Katsuoka, and
M Miyazaki
December 1994,
The American journal of physiology,
