Application of the t,echnique of counter-current distribution t,o the purificat,ion of the pressor principle from beef post’erior pituitary glands has afforded preparations with potencies of over 400 pressor units per mg. (1). Analysis of hydrolysates of such preparations for constituent amino acids by chromatography on starch has shown that they contain approximately equimolar amounts of the e...

Alkyl nitrates are metabolized in vitro to yield nitric oxide, and thiol groups have long been considered necessary cofactors. Here, we report evidence that no reaction between thiols and alkyl nitrates takes place in vitro, but stronger reducing agents, such as iron(II) derivatives, are necessary; alkoxy radicals and nitrite anions are the reaction intermediates. The latter, in slightly acidic...