Effects of age on right ventricular hypertrophic response to pressure-overload in rats.
To examine the effects of age on hypertrophic response to pressure-overload in the right ventricle, we determined the rate and extent of hypertrophy in three age groups of Wistar rats: 2, 7 and 18 months. We created pulmonary artery constriction so that increases in right ventricular pressure were similar in those groups. One or 3 weeks after pulmonary artery constriction, the rats were sacrificed and hypertrophic response was estimated from right ventricular weight, myocyte width and protein content. In the 2-month-old rats, significant hypertrophy was observed 1 and 3 weeks after pulmonary artery constriction in terms of right ventricular weight/body weight (161% of controls at 1 week and 209% at 3 weeks), right ventricular weight/tibial length (161 and 251%, respectively) and right ventricular weight/left ventricular weight (174 and 211%, respectively). In the 7-month-old rats, significant hypertrophy was observed only at 3 weeks, but was not observed even at 3 weeks in the 18-month-old rats. The age-associated decrease and delay in hypertrophic response was also observed at cellular (myocyte width) and biochemical (protein content) levels. Thus, there is an age-associated diminution in the rate and extent of myocardial hypertrophy in the right ventricle.
Kuroha
M
M
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Isoyama
S
S
Ito
N
N
Takishima
T
T
D000375:Aging / Q000473:pathology*; D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight; D006332:Cardiomegaly / Q000473:pathology* / Q000503:physiopathology; D003251:Constriction, Pathologic; D006352:Heart Ventricles; D008297:Male; D009206:Myocardium / Q000473:pathology; D009929:Organ Size; D011312:Pressure; D011506:Proteins / Q000378:metabolism; D011651:Pulmonary Artery; D051381:Rats; D011919:Rats, Inbred Strains; D016278:Ventricular Function, Right / Q000502:physiology*
D011506:Proteins