Rj. Macallister et al., RELATIVE POTENCY AND ARTERIOVENOUS SELECTIVITY OF NITROVASODILATORS ON HUMAN BLOOD-VESSELS - AN INSIGHT INTO THE TARGETING OF NITRIC-OXIDE DELIVERY, The Journal of pharmacology and experimental therapeutics, 273(1), 1995, pp. 154-160
The arteriovenous potency of sodium nitroprusside (SNP), linsidomine (
SIN-1) and S-nitrosoglutathione (GSNO) was determined in human capacit
ance (veins) and resistance (arterioles) vessels in vitro and in vivo
and compared with the venoselective nitrovasodilator nitroglycerin (GT
N). Concentration-response curves were constructed to GTN, SNP, GSNO a
nd SIN-1 (0.001-10 mu M) in preconstricted human saphenous vein and to
GTN, GSNO and SIN-1 (0.001-10 mu M) in omental resistance vessels. In
vivo the dilator responses of the dorsal hand vein and the forearm re
sistance bed were recorded during local infusions of GTN, SNP, GSNO an
d SIN-1 (1 pmol/min to 160 nmol/min). SNP and SIN-1 had similar arteri
ovenous profiles to that of GTN. SNP was equipotent with GTN in arteri
oles and veins but SIN-1 was 10-fold less potent than GTN in vitro and
100-fold less potent in vivo; the potency of SIN-1 was increased afte
r incubation of saphenous vein with superoxide dismutase. GSNO was equ
ipotent with GTN in arterioles but 10-fold less potent in veins in vit
ro and in vivo. These results demonstrate that most nitrovasodilators
are venoselective irrespective of their mechanism of biotransformation
to nitric oxide (NO) and suggests that NO itself might be venoselecti
ve in vivo. Endogenous carrier molecules, including glutathione, could
alter the vascular profile of NO with physiological and therapeutic i
mplications.