CHANGES OF ? ADRENERGIC RECEPTORS AND ANGIOTENSIN Ⅱ RECEPTORS IN SPONTANEOUSLY HYPERTENSIVE RATS AND DIFFERENT AGES WKY RAT HEARTS / 解放军医学杂志

ABSTRACT

To study the changes of ? adrenergic receptor subtypes (? 1 AR,? 2 AR) and angiotensin Ⅱreceptor subtypes (AT 1 R,AT 2 R)mRNA levels in spontaneously hypertensive rat (SHR) hearts at 14 weeks of age, and WKY rat hearts at ages 14 and 48 weeks, the total cellular RNA was extracted from the left ventricular tissue, and reverse polymerase chain reaction analysis was performed for measurement of the four receptors. The expression levels of ? 1 AR mRNA and ? 2 AR mRNA were down regulated in WKY hearts at age 48 weeks and in 14 week SHR. AT 1 R mRNA levels were decreased in 48 week WKY and 14 SHR, and AT 2 R mRNA levels were significantly increased in SHR. The expression levels of ? 1 AR and AT 1 R mRNA were declined following the increase of ages. The levels of ? 2 AR mRNA were down regulated in hypertension and myocardial hypertrophy conditions first because ? 2 AR was more sensitive to myocardial hypertrophy than ? 1 AR. Long term and hyper AngⅡ levels stimulated AT 1 R mRNA down regulation in SHR, and it is the myocardial hypertrophic compensatory process that increases the AT 2 R mRNA levels.