Expression of G Protein Subunits in the Aging Cardiovascular System

Publisher Website
Google Scholar
Abstract
Alterations in responsiveness to stimulation of G protein-coupled receptors in the cardiovascular system have been noted during aging and may be due to changes in the G proteins. The levels of G protein α subunits and their in RNAs were examined in the aorta and heart of adult (6-month-old) and senescent (24-month-old) Fischer 344 rats. Western blot analysis using anti-Gsα antiserum revealed 4 bands in the aorta (38,42,45, and 52 kD). The 42 kD) band decreased significantly in 24-month-old rats, whereas the other bands did not change. Western blots using anti-Goα and anti-Giα revealed single bands of 39 kD and 41 kD respectively, which decreased significantly in the aortas from 24-month-old rats. There were no significant changes in the levels of Gα mRNAs in the aorta during aging. In the heart, anti-Gsα antiserum detected 3 bands (42, 45, and 52 kD) which did not change with age. Levels of Giα (41 kD) and Goα (39 kD) also did not change with age in the heart. The mRNAs for Gi2α and Gi3α were significantly increased in the heart, but there was no change in Goα or Gsα mRNAs. Reduced expression ofGiα and Goα may provide the molecular basis for alterations in receptor responsiveness in the aging vasculature. Altered expression of G protein a subunits does not appear to account for age-related alterations in cardiac function.

This publication has 0 references indexed in Scilit: