Leptin has been hypothesized to be a pathophysiologic link between obesity and cardiovascular diseases. Because the adenylate cyclase (AC) system is a main effector of -adrenergic receptors and leptin has been shown to modulate AC activity in other cell lines, a leptin impact on cardiac AC activity was hypothesized. Therefore, acute and chronic effects of leptin on a rat cardiac cell line (H9c2) were investigated. Leptin affected both basal (13% at 30 min and 16.4% after 18 h v untreated cells) and catecholamine-stimulated AC activity (isoproterenol leptin at 30 min or 18 h was 21% v untreated cells; norepinephrine leptin at 30 min was 38.8% v untreated cells; and norepinephrine leptin at 18 h was 6% v untreated cells). Thus, long-term leptin treatment was associated with a reduced AC activity and a different responsiveness to catecholamines. The AC activity on leptin treatment was accompanied by changes in levels of proteins structurally or functionally related to AC complex (AC, Gs, Gi, p21-ras). These data indicate that the AC complex is profoundly affected at more than one level by leptin treatment in the H9c2 cardiac cell line. Differences in AC activity after short- and long-term exposure to leptin and the interaction between leptin and catecholamine might provide further insight to the understanding of the development of hypertension and congestive heart failure in obese patients.

Leptin affects adenylate cyclase activity in H9c2 cardiac cell line: effects of short- and long-term exsposure

NAVIGLIO, Silvio;SPINA, Annamaria;CHIOSI, Emilio;BARBIERI, Michelangela;PAOLISSO, Giuseppe
2002

Abstract

Leptin has been hypothesized to be a pathophysiologic link between obesity and cardiovascular diseases. Because the adenylate cyclase (AC) system is a main effector of -adrenergic receptors and leptin has been shown to modulate AC activity in other cell lines, a leptin impact on cardiac AC activity was hypothesized. Therefore, acute and chronic effects of leptin on a rat cardiac cell line (H9c2) were investigated. Leptin affected both basal (13% at 30 min and 16.4% after 18 h v untreated cells) and catecholamine-stimulated AC activity (isoproterenol leptin at 30 min or 18 h was 21% v untreated cells; norepinephrine leptin at 30 min was 38.8% v untreated cells; and norepinephrine leptin at 18 h was 6% v untreated cells). Thus, long-term leptin treatment was associated with a reduced AC activity and a different responsiveness to catecholamines. The AC activity on leptin treatment was accompanied by changes in levels of proteins structurally or functionally related to AC complex (AC, Gs, Gi, p21-ras). These data indicate that the AC complex is profoundly affected at more than one level by leptin treatment in the H9c2 cardiac cell line. Differences in AC activity after short- and long-term exposure to leptin and the interaction between leptin and catecholamine might provide further insight to the understanding of the development of hypertension and congestive heart failure in obese patients.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11591/232324
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