Inhibitory effect of Ca2+ on ATP-mediated stimulation of NPR-A-coupled guanylyl cyclase in renal glomeruli from spontaneously hypertensive and normotensive rats

• Autorzy: Woodard G.E. , Zhao J. , Rosado J.A.
• Języki publikacji: EN

Abstrakty

EN

Atrial natriuretic peptide (ANP) regulates blood pressure mainly through the occupation of the guanylyl cyclase-coupled receptor NPR-A, which requires ATP interaction for maximal activation. This study investigates the effect of extracellular Ca2+ on ATP-mediated regulation of NPR-A-coupled guanylyl cyclase activity in glomerular membranes from Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). ATP induced a significant increase in basal and ANP1-28-stimulated guanylyl cyclase activity that was greater in SHR than in WKY. Extracellular Ca2+ inhibited ATP-stimulated guanylyl cyclase activity in a concentration-dependent manner, but did not modify basal and ANP1-28-stimulated guanylyl cyclase activity. In the presence of ATP, NPR-A showed higher affinity for ANP1-28 and lower Bmax. Ca2+ did not modify NPR-A-ANP1-28 binding properties. The different effects of extracellular Ca2+ on ANP1-28- or ATP-mediated guanylyl cyclase activation suggest that these events are differentially regulated. Addition of extracellular Ca2+ induced similar effects in hypertensive and normotensive rats, suggesting that it is not responsible for the elevated cGMP production observed in SHR.

Słowa kluczowe

EN

normotension; inhibitory effect; hypertension; atrial natriuretic peptide; rat; blood pressure; renal glomerulus

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2006
• Tom: 57
• Numer: 3
• Opis fizyczny: p.359-373,fig.,ref.

Twórcy

autor

Woodard G.E.

• National Institute of Health, 10 Center Drive, MSC 1752 Bethesda, MD 20892-1752, USA

autor

Zhao J.

autor

Rosado J.A.