Urotensin I effects on intracellular content on cyclic AMP in the rat tail artery

摘要: Abstract Rat tail artery strips were incubated in the presence of 4 × 10 −3 M theophylline and urotensin I (UI). At concentrations 1.50, 7.50 mU/ml but not 0.75 UI, content cAMP increased significantly. Cyclic AMP muscle tension measured at 5–30 sec intervals during noradrenaline (NA)- potassium chloride (KCl)-induced contractions subsequent I-induced relaxation. declined initially after addition NA returned to baseline levels contraction. Significant dose-related increases noted upon prior onset relaxation response followed by a marked decrease response. An increase was observed initiation contractile KCl-contracted tissues, no further UI detected. These findings suggest an involvement cyclic initial events leading NA-contracted rat artery. Urotensin KC1-contracted tissues appears proceed alternative mechanism which does require tissue cAMP.