Lack of prejunctional modulation of noradrenaline release by endogenous nitric oxide in guinea pig pulmonary artery.
The regulation of noradrenaline (NA) release by endogenous endothelium-derived compounds was investigated in the isolated guinea pig pulmonary artery preloaded with [3H]NA. The radioactivity uptake, the basal and electrical field stimulation (10 Hz, 2 ms, 360 shocks) evoked release of [(3)H]NA was similar in arteries with intact endothelium and after removal of the endothelium. The wide selectivity nitric oxide (NO) synthase inhibitor N-omega-nitro-L-arginine (100 microM) did not affect significantly the basal and stimulation-evoked release of [(3)H]NA in control and endothelium-denuded preparations. These results indicate that neither endogenous NO nor other compounds derived from the endothelium have substantial influence on the NA outflow from sympathetic nerves innervating the pulmonary artery.
Brassai
Attila
A
University of Medicine and Pharmacy, Tirgu-Mures, Romania.
Makó
Katalin
K
Domjanschitz
László
L
Sperlágh
Beáta
B
D000818:Animals; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D011651:Pulmonary Artery / Q000378:metabolism* / Q000502:physiology
D004791:Enzyme Inhibitors; D019335:Nitroarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D009638:Norepinephrine