This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, D. H. Articles by Hu, Z. Search for Related Content PubMed PubMed Citation Articles by Wang, D. H. Articles by Hu, Z.

(Hypertension. 1998;32:65-70.)
© 1998 American Heart Association, Inc.

Scientific Contributions

Differential Regulation of Angiotensin II Receptor Subtypes in the Adrenal Gland

Role of Aldosterone

Donna H. Wang; Jingxin Qiu; ; Zhaoyong Hu

From the Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas.

Correspondence to Donna H. Wang, MD, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555-1065. E-mail dwang{at}utmb.edu

Abstract—It has been shown that aldosterone potentiates the action of angiotensin II (Ang II) in cultured rat vascular smooth muscle cells solely by increasing the number of Ang II receptors. The mechanisms responsible for aldosterone–Ang II interactions in the adrenal gland are unknown. The present study was designed to investigate the effect of aldosterone on expression of Ang II receptor subtypes (AT₁ and AT₂) in the adrenal gland. Seven-week-old male Wistar rats were treated for 2 weeks with either aldosterone (0.05 µg/h, n=14) or vehicle (n=14) by use of implanted osmotic minipumps. Systolic blood pressure was not altered by aldosterone treatment. Plasma aldosterone levels were higher in aldosterone-treated rats (181±53 pg/mL) compared with vehicle-treated rats (33±21 pg/mL, P<0.05). Northern blot analysis and radioligand binding assay showed that adrenal AT₁ mRNA levels and AT₁ receptor density in aldosterone-treated rats were not statistically different from those of vehicle-treated rats. However, immunohistochemical studies showed that the highest adrenal AT₁ receptor expression was shifted from the zona glomerulosa to the zona fasciculata after aldosterone treatment. In contrast, adrenal AT₂ mRNA and AT₂ receptor density in aldosterone-treated rats were decreased by approximately 50% and 40%, respectively, compared with vehicle-treated rats (P<0.05). Aldosterone-induced decrease in adrenal AT₂ receptor expression occurred mainly in the medulla. Thus, aldosterone differentially modulates the expression of AT₁ and AT₂ receptors in the adrenal gland. Although the function of the AT₂ receptor in the adrenal gland is largely unknown, our data indicate that aldosterone may modulate the effect of Ang II by altering the location of AT₁ receptors and by reducing the number of AT₂ receptors in the adrenal gland.

Key Words: aldosterone • receptors, angiotensin II • adrenal gland • Northern blot • radioligand assay • immunohistochemistry

This article has been cited by other articles:

				F. Xiao, J. R. Puddefoot, S. Barker, and G. P. Vinson Mechanism for Aldosterone Potentiation of Angiotensin II-Stimulated Rat Arterial Smooth Muscle Cell Proliferation Hypertension, September 1, 2004; 44(3): 340 - 345. [Abstract] [Full Text] [PDF]

				A. F. Moore, N. T. Heiderstadt, E. Huang, N. L. Howell, Z.-Q. Wang, H. M. Siragy, and R. M. Carey Selective Inhibition of the Renal Angiotensin Type 2 Receptor Increases Blood Pressure in Conscious Rats Hypertension, May 1, 2001; 37(5): 1285 - 1291. [Abstract] [Full Text] [PDF]

				S. Gallinat, S. Busche, M. K. Raizada, and C. Sumners The angiotensin II type 2 receptor: an enigma with multiple variations Am J Physiol Endocrinol Metab, March 1, 2000; 278(3): E357 - E374. [Abstract] [Full Text] [PDF]

				Z.-Q. Wang, L. J. Millatt, N. T. Heiderstadt, H. M. Siragy, R. A. Johns, and R. M. Carey Differential Regulation of Renal Angiotensin Subtype AT1A and AT2 Receptor Protein in Rats With Angiotensin-Dependent Hypertension Hypertension, January 1, 1999; 33(1): 96 - 101. [Abstract] [Full Text] [PDF]