Effects of relaxin on vascular smooth muscle and endothelial cells in normotensive and hypertensive rats.
We tested the effects of relaxin on [Ca2+]i response to angiotensin II in smooth muscle (vSMC) and endothelial cells isolated from hypertensive (SHR) and normotensive (WKY) rats. Relaxin markedly reduced the [Ca2+]i response of vSMCs from WKY, but not from SHR rats. Western blots showed that cGMP-dependent protein kinase G was reduced in vSMCs from SHR as compared with WKY rats. Relaxin also blunted the [Ca2+]i response in endothelial cells from WKY, but not from SHR rats. However, in endothelial cells from SHR and WKY rats, protein kinase G was nearly unexpressed, thus accounting for an alternative pathway of the intracellular response to nitric oxide and relaxin. Hence, vSMCs and endothelial cells in SHR rats show a deficiency response to nitric oxide that may render them insensitive to relaxin.
Failli
Paola
P
Department of Preclinical and Clinical Pharmacology, University of Florence, Florence, Italy.
Nistri
Silvia
S
Mazzetti
Luca
L
Chiappini
Laura
L
Bani
Daniele
D
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D006973:Hypertension / Q000473:pathology* / Q000503:physiopathology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology / Q000503:physiopathology; D051381:Rats; D012065:Relaxin / Q000494:pharmacology*
D012065:Relaxin; D002118:Calcium