1 The in vitro motor function of protease-activated recepter-1 (PAR-1), PAR-2 and PAR-4 and the presence by immunohistochemistry of PAR-1 in the human renal artery have been investigated. 2 Thrombin and the human PAR-1 (SFLLRN-NH2) activating peptide, but not the PAR-1 reverse peptide (NRLLFS-NH2), contracted both endothelial-intact and endothelial-denuded human renal artery strips, whereas no relaxation was observed either in strips non-precontracted or precontracted with phenylephrine. Maximum contraction by thrombin or SFLLRN-NH2 was about 60% of phenylephrine. However, thrombin was approximately 1000-fold more potent than SFLLRN-NH2. 3 PAR-1 desensitisation, using repeated applications of SFLLRN-NH2, almost completely blocked the response to thrombin. The contractile effect produced by thrombin and SFLLRN-NH2 was not affected by nitric oxide synthase inhibition, but was significantly reduced by cyclooxygenase blockade. 4 Trypsin, the PAR-2 (SLIGKV-NH2 and SLIGRL-NH2) and PAR-4 (GYPGQV-NH2 and AYPGKF-NH2) activating peptides did not produce any significant contraction or relaxation. 5 In agreement with the motor function data immunohistochemistry showed specific staining patterns for PAR-1 in the human renal artery. 6 Combined, these studies would suggest a possible role for PAR-1 in renal vascular homeostasis.
Proteinase-activated receptor-1 (PAR-1) activation contracts the isolated human renal artery in vitro
GUERRINI, Remo;SALVADORI, Severo;
2003
Abstract
1 The in vitro motor function of protease-activated recepter-1 (PAR-1), PAR-2 and PAR-4 and the presence by immunohistochemistry of PAR-1 in the human renal artery have been investigated. 2 Thrombin and the human PAR-1 (SFLLRN-NH2) activating peptide, but not the PAR-1 reverse peptide (NRLLFS-NH2), contracted both endothelial-intact and endothelial-denuded human renal artery strips, whereas no relaxation was observed either in strips non-precontracted or precontracted with phenylephrine. Maximum contraction by thrombin or SFLLRN-NH2 was about 60% of phenylephrine. However, thrombin was approximately 1000-fold more potent than SFLLRN-NH2. 3 PAR-1 desensitisation, using repeated applications of SFLLRN-NH2, almost completely blocked the response to thrombin. The contractile effect produced by thrombin and SFLLRN-NH2 was not affected by nitric oxide synthase inhibition, but was significantly reduced by cyclooxygenase blockade. 4 Trypsin, the PAR-2 (SLIGKV-NH2 and SLIGRL-NH2) and PAR-4 (GYPGQV-NH2 and AYPGKF-NH2) activating peptides did not produce any significant contraction or relaxation. 5 In agreement with the motor function data immunohistochemistry showed specific staining patterns for PAR-1 in the human renal artery. 6 Combined, these studies would suggest a possible role for PAR-1 in renal vascular homeostasis.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
