Polyphosphoinositide metabolism in hypertrophic rat heart.
The accumulations of inositol-1,4,5-trisphosphate (IP3) and inositol-1,3,4,5-tetrakisphosphate (IP4) after hormonal stimulation may have a physiological role, possibly by alteration of Ca2+ levels in cardiac tissue. But the accumulation of inositol polyphosphate in a pathophysiological condition has not been studied. We investigated phosphatidylinositol-4,5-bisphosphate (PIP2) metabolism in hypertrophic cardiac myocytes, and clarified that the accumulations of IP3, IP4 and diacylglyceride after stimulation with norepinephrine were significantly enhanced in isolated myocytes from spontaneously hypertensive rat heart. Phospholipase C activity increased with age in SHRSP heart cells. These data suggest that PI turnover pathways, which can be mediated by both phosphatidylinositol-4,5-bisphosphate and diacylglyceride, may play an important role in development of hypertrophy in the hearts of rats with spontaneous hypertension.
Kawaguchi
H
H
Department of Cardiovascular Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
Shoki
M
M
Sano
H
H
Kudo
T
T
Sawa
H
H
Mochizuki
N
N
Okamoto
H
H
Endo
Y
Y
Kitabatake
A
A
D000818:Animals; D006332:Cardiomegaly / Q000209:etiology / Q000378:metabolism*; D006973:Hypertension / Q000150:complications; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D010738:Type C Phospholipases / Q000378:metabolism
D007295:Inositol Phosphates; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; C081655:inositol-1,3,4,5-tetrakisphosphate; D015544:Inositol 1,4,5-Trisphosphate; D010738:Type C Phospholipases; D009638:Norepinephrine