Figure 1.

Contractile responses of the rabbit basilar artery to high K⁺ depolarization, endothelin-1, thrombin, and phenylephrine and the expression of ET_A receptor, proteinase-activated receptor 1 (PAR₁), and α₁-adrenoceptor in the controls and subarachnoid hemorrhage (SAH). (A) Representative recordings showing the 118 mmol/L K⁺-induced contractions in the fura-2-unloaded basilar artery of controls and SAH. (B) The level of tension induced by 118 mmol/L K⁺ depolarization in the controls and SAH, as expressed in absolute value (n=5). (C) Concentration-dependent effect of high K⁺ depolarization on the tension development in the controls and SAH (n=5). (D) The concentration-response curves of the contraction induced by endotheliln-1, thrombin, and phenylephrine in the basilar artery of the controls and SAH (n=5 to 7). (E) Immunoblot analysis of the expression of ET_A receptor, PAR₁, and α₁-adrenoceptor in the basilar artery of the controls and SAH (n=4 to 5). The level of tension obtained in normal physiological salt solution (PSS) and 118 mmol/L K⁺ PSS were assigned values of 0% and 100%, respectively. The level of expression observed in the controls was assigned to be 100%. The data represent the mean±s.e.m. n.s., not significantly different; ^*P<0.05 versus controls.