Effect of hemorrhage on mRNA expressions of renin, angiotensinogen and AT-1 receptors in rat central and peripheral tissues.
- Author:
Mi Kyung LEE
1
;
Hakryul JO
;
Kyung Soo KIM
;
Eun Kyoung YANG
;
Won Jung LEE
Author Information
1. Department of Physiology, School of Medicine, Kyungpook National University ,101 Tong-in 2 Ka,Chungku, Taegu 700-422 South Korea.
- Publication Type:Original Article
- Keywords:
Northern blot;
RT-PCR;
Brain;
Kidney;
Liver;
Adrenal
- MeSH:
Adrenal Glands;
Angiotensinogen*;
Angiotensins;
Animals;
Blood Pressure;
Blotting, Northern;
Brain;
Brain Stem;
Down-Regulation;
Gene Expression;
Heart Rate;
Hemorrhage*;
Hypotension;
Hypothalamus;
Kidney;
Liver;
Plasma;
Rats*;
Rats, Wistar;
Renin*;
Renin-Angiotensin System;
RNA, Messenger*;
Tachycardia;
Up-Regulation
- From:The Korean Journal of Physiology and Pharmacology
1997;1(2):151-159
- CountryRepublic of Korea
- Language:English
-
Abstract:
In an attempt to investigate whether hemorrhage affects the gene expression of the renin-angiotensin system (RAS) components in the brain and peripheral angiotensin-generating tissues, changes in mRNA levels of the RAS components in response to hemorrhage were measured in conscious unrestrained rats. Wistar rats were bled at a rate of 3 ml/kg/min for 5 min, and then decapitated 7 h after hemorrhage. Levels of mRNA for renin, angiotensinogen and angiotensin II-AT-1 receptor subtypes (AT-1A and AT-1B) were determined with the methods of northern blot and reverse transcriptase-polymerase chain reaction (RT-PCR). Hemorrhage produced a profound hypotension with tachycardia, but blood pressure and heart rate recovered close to the basal level at 7 h. Plasma and renal renin levels were significantly increased at 7 h. Hemorrhage induced rapid upregulation of gene expression of both AT-1A and AT-1B receptor subtypes in the brainstem and hypothalamus, downregulation of them in the adrenal gland and liver. However, renin mRNA level increased in the brainstem, decreased in the liver, but was not changed in the hypothalamus, kidney and adrenals after hemorrhage. Angiotensinogen mRNA level was not significantly changed in any of the tissue except a slight increase in the liver. The kidney and liver did not show any significant change in gene expression of the RAS components. These results suggest that gene expression of the RAS in central and peripheral tissues are, at least in part, under independent control and the local RAS in each organ plays specific physiologic role.
