N-nitro-L-arginine and N-monomethyl-L-arginine exhibit a different pattern of inactivation toward the three nitric oxide synthases.

The ability of NG-nitro-L-arginine (NNA) and NG-methyl-L-arginine (NMMA) to inactivate native neuronal, endothelial cell, and macrophage nitric oxide synthases (nNOS, eNOS, and iNOS, respectively) was investigated. Each NOS isozyme (plus cofactors) was preincubated with either NNA or NMMA and then assayed for remaining activity by measuring the conversion of labeled L-arginine to labeled L-citrulline. Consistent with previous reports (Olken, N.

In vitro muscarinic activity of spiromuscarones and related analogs.

The cholinergic hypothesis of Alzheimer's disease suggests that cholinergic agonists may have therapeutic potential for treating the attendant memory deficits of the disease. As part of a program aimed at preparing metabolically stable, nonquaternary analogs of muscarone, 1-oxa-2,8-dimethyl-8-azaspiro[4.5]decan-3-one, 2a, and related analogs have been synthesized and their in vitro muscarinic activity evaluated.

Preclinical profile of the anticonvulsant remacemide and its enantiomers in the rat.

Studies conducted by Fisons Pharmaceuticals and the Antiepileptic Drug Development Program (ADD Program) of the Epilepsy Branch (NINDS, NIH) revealed that 'remacemide' (FPL 12924, formerly PR 934-423) was effective orally in the prevention of maximal electroshock seizures (MES) in rats. In this context (-)stereoisomer (FPL 14145) was of equal potency to the racemate (remacemide), while the (+)stereoisomer (FPL 14144) was 54% less potent. With respect to neurotoxicity, remacemide and its enantiomers possessed more favorable therapeutic indices than phenobarbital and valproate and less favorable indices than phenytoin and carbamazepine.

Flavodilol: a new antihypertensive agent that preferentially depletes peripheral biogenic amines.

Flavodilol, ((+/-)-7-[2-hydroxy-3-(propylamine)-propoxy]flavone maleate), a new orally effective antihypertensive agent, extensively depleted catecholamines and serotonin in heart tissue of normotensive and spontaneously hypertensive rats (SHR). Dose-response studies demonstrated that greater than or equal to 75% depletion of cardiac norepinephrine (NE) was accompanied by marked blood pressure decline in SHR. In contrast, whole brain biogenic amine levels were decreased only by 15-20% after acute or chronic treatment with antihypertensive doses (35-75 mg/kg).