The role of guanine nucleotide binding proteins in hamsters with myocardial hypertrophy.
To clarify the role of the guanine nucleotide binding proteins (G-proteins) in the pathogenesis of myocardial hypertrophy, we investigated the alterations in myocardial G proteins in 20-week-old F1b hamsters with pressure overload induced for 3 days (3-day AS), 7 days (7-day AS) and 14 days (14-day AS) by the stenosis of the abdominal aorta, and in 4- and 20 week-old BIO 14.6 Syrian hamsters (4-wk and 20-wk BIO) with genetic myocardial hypertrophy. The hearts of 7-day AS, 14-day AS and 20-wk BIO with left ventricular hypertrophy exhibited a decrease in the mRNA levels detected by Northern blot analysis and protein levels of G protein detected by Western blot analysis as compared with sham-operated and age-matched F1b hearts. The function of Gs or Gi showed a concomitant reduction in both models of myocardial hypertrophy. The hearts of 3-day AS and 4-wk BIO without myocardial hypertrophy showed no changes in G proteins as compared with sham-operated and age-matched F1b hearts. These results suggest that a decrease in G proteins is not involved in the pathogenesis of myocardial hypertrophy, but that myocardial hypertrophy reduced the G proteins.
First Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan.
K
K
Nakamura
M
M
Ohyanagi
J
J
Shibuya
J
J
Yamamoto
T
T
Iwasaki
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D001835:Body Weight; D006332:Cardiomegaly / Q000209:etiology* / Q000378:metabolism; D006224:Cricetinae; D019204:GTP-Binding Proteins / Q000235:genetics / Q000502:physiology*; D008297:Male; D008647:Mesocricetus; D009929:Organ Size; D012333:RNA, Messenger / Q000032:analysis
D012333:RNA, Messenger; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases