Blocking utilization of tetrahydrobiopterin to block induction of nitric

Abstract

Inhibitor of the use of tetrahydrobiopterin as a cofactor for nitric oxide synthase, e.g., substituted 4-phenyl(hydropyridines) such as 1-methyl-4-(3',4'-dihydroxyphenyl)-1,2,3,6-tetrahydropyridine or, 4-(3',4'-dihydroxyphenyl)-1,2,3,6-tetrahydropyridine) or tetrahydropterin analog which does not replace tetrahydrobiopterin as a substrate for nitric oxide synthase such as (6R,S)-6,7-dimethyl-tetrahydropterin or (6R,S)-tetrahydrofolic acid or 2,4-diamino-, 2,6-diamino, or 4,6-diamino mono- or disubstituted pyrimidines or the corresponding pyrimidine-3-oxides such as 2,4-diamino-6-(diethylamino)pyrimidine, 2,4-diamino-6-piperidino-pyrimidine-3-oxide, 2,4-diamino-6-hydroxypyrimidine, 4,6-diamino-2-hydroxypyrimidine or 2,5-diamino-4,6-dihydroxypyrimidine is administered to inhibit nitric oxide synthesis from arginine in vascular cells in a subject in need of such inhibition (e.g., for prophylaxis or treatment of cytokine- or endotoxin-induced hypotension (e.g., septic shock). The latter two types are advantageously administered with nitric oxide synthase inhibitors (concurrent therapy) or to potentiate the effect of .alpha..sub.1 -adrenergic agonists in the prophylaxis or treatment of induced hypotension.