Alterations of mRNA levels of alpha 1-adrenoceptor subtypes with maturation and ageing in different rat blood vessels.

1. Alterations of mRNA levels of alpha 1-adrenoceptor subtypes during maturation and ageing were determined by reverse transcription-polymerase chain reaction (RT-PCR) in aortae and renal, pulmonary and mesenteric arteries isolated from 3, 12 and 24-month-old rats. 2. The steady state levels for alpha 1A-, alpha 1B- and alpha 1D-adrenoceptors in aorta declined with maturation and ageing. In renal artery there was a decrease in mRNA for the alpha 1B-adrenoceptor in aged rats. However, in mesenteric and pulmonary arteries there were no changes in mRNA levels for the three subtypes of alpha 1-adrenoceptors as a result of maturation and ageing. 3. The results suggest that expression of alpha 1-adrenoceptors is changed heterogeneously in different blood vessels during maturation and ageing in rats.