A tonic component in the motility of the upper urinary tract (renal pelvis-ureter).
In isolated muscle strips of porcine renal pelvis and ureter, the calcium antagonist nifedipine (3.10(-7) moles/l) completely suppressed spontaneous phasic mechanical activity and the phasic components of an adrenaline-induced activation (P-component). In the presence of nifedipine, adrenaline induced in pelvis preparations (but not in the ureter) a tonic contraction (T-component) which was on average 61% of the control reaction (SD +/- 26%; n = 35).
D000818:Animals; D004837:Epinephrine / Q000494:pharmacology; D007682:Kidney Pelvis / Q000187:drug effects*; D009119:Muscle Contraction / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D010208:Papaverine / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology*; D011817:Rabbits; D013552:Swine; D014513:Ureter / Q000187:drug effects*
D011725:Pyridines; D009599:Nitroprusside; D010208:Papaverine; D009543:Nifedipine; D004837:Epinephrine