Endostatin inhibits T-type Ca2+ channel current in guinea pig
ventricular myocyte |
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Authors: | Jumpei YASUDA Muneyoshi OKADA Hideyuki YAMAWAKI |
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Institution: | 1)Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Higashi 23 bancho 35–1, Towada-shi, Aomori 034–8628, Japan |
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Abstract: | Endostatin, a fragment of collagen XVIII, is known as an endogenous angiogenesis
inhibitor, and its serum concentration increases in various cardiovascular diseases.
T-type Ca2+ channel, low voltage-activated Ca2+ channel, is not
expressed in adult ventricular myocytes. Re-expression of T-type Ca2+ channels
in cardiac myocytes is thought to be involved in the development of cardiac hypertrophy.
We examined the effects of endostatin on T-type Ca2+ channel current by
whole-cell patch clamp technique in freshly isolated adult guinea pig ventricular
myocytes, which exceptionally express T-type Ca2+ channels. Although endostatin
300 ng/ml had no effect on L-type Ca2+
current, it significantly inhibited T-type Ca2+ current. These data indicate
that endostatin can be an endogenous inhibitor of T-type Ca2+ channels in the
cardiac myocytes. |
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Keywords: | endostatin guinea pig ventricular myocyte T-type Ca2+channel |
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