Effects of substance P on isolated preparations from rabbit and rat renal arteries.
Substance P (SP) increased the tone of isolated ring preparations from renal and pulmonary arteries from rat but not from rabbit. Indomethacin decreased the amplitude of SP-evoked tone by 50%. SP inhibited in a dose-dependent manner the electrically-evoked contractions of the rabbit and rat renal arteries. The threshold concentrations producing inhibitory effects of SP were 10(-12) M for rabbit arteries and 10(-9) M for rat arteries. The maximal inhibition was observed at 10(-8) M and 10(-6) M, respectively. In the renal arteries of spontaneously hypertensive rats SP potentiated the electrically-evoked contractions. SP caused relaxation of the rabbit renal arteries, previously contracted with noradrenaline (10(-7) M), high [K+]0 (30 mM) and prostaglandin F2 alpha (10(-6) M). The results have shown that the effects of SP on the arterial contractions depend on the species and on the normal or pathologic conditions. A direct action of SP on the arterial muscle cells is suggested.
Bredy-Dobreva
G
G
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Zafirov
D
D
Nieber
K
K
Oehme
P
P
Papasova
M
M
D000818:Animals; D015237:Dinoprost; D004558:Electric Stimulation; D007213:Indomethacin / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology; D011651:Pulmonary Artery / Q000187:drug effects / Q000502:physiology; D011817:Rabbits; D051381:Rats; D011918:Rats, Inbred SHR; D012077:Renal Artery / Q000187:drug effects / Q000502:physiology; D013373:Substance P / Q000494:pharmacology*
D011460:Prostaglandins F; D013373:Substance P; D011433:Propranolol; D015237:Dinoprost; D011188:Potassium; D009638:Norepinephrine; D007213:Indomethacin; D010646:Phentolamine