Aggregation induced by adenosine diphosphate is inhibited by adenosine as well as by adenosine mono- and triphosphate. Thrombin-induced aggregation is also inhibited by adenosine and the monophosphate, but the triphosphate at a similar concentration is not inhibitory. Aggregation induced by tri-ethyl tin is accelerated by a critical concentration of triphosphate and delayed by a higher concentr...

PURPOSE Adenosine triphosphate is thought to be an important neurotransmitter in urethral smooth muscle but its physiological role is still unclear. We characterized the effects of adenosine triphosphate on contractile and pacemaker activity in rabbit urethral smooth muscle. MATERIALS AND METHODS Tension recordings were made from strips of rabbit proximal urethral smooth muscle. Membrane curr...

A study of the exchange reactions between adenosine triphosphate and either radioactive inorganic phosphate, or adenosine diphosphate (l), catalyzed by propionyl carboxylase, showed that inorganic phosphate was required for adenosine triphosphate-adenosine diphosphate exchange and, conversely, adenosine diphosphate was required for adenosine triphosphateinorganic phosphate exchange. A requireme...

The preceding paper (2) describes experiments on the synthesis of glutamine in pigeon liver dispersions, which, together with the results of Krebs and his collaborators (3, 4) and of Bujard and Leuthardt (5), suggested that adenosine triphosphate may play an essential r81e in amide formation. Proof for this function of adenosine triphosphate has been obt.ained in studies with tissue extracts, w...

The ultramicro (1-microL samples) assay of serum or plasma triglycerides that we describe here is potentially applicable to 1-nL samples and to isolated cells. This technically simple method involves only three reactions: (a) enzymic hydrolysis with lipase and alpha-chymotrypsin; (b) conversion by glycerol kinase of the liberated glycerol and of adenosine triphosphate added in excess to glycero...

The clearing of actomyosin at p = 0.15 to 0.16 and pH 7.0 brought about by adenosine triphosphate in the presence of added magnesium was interpreted in the preceding paper in terms of the dissociation of actomyosin into its components (2). This report deals with various factors influencing the clearing reaction and the accompanying changes in adenosine triphosphatase activity. Adenosine triphos...

The clearing of actomyosin at p = 0.15 to 0.16 and pH 7.0 brought about by adenosine triphosphate in the presence of added magnesium was interpreted in the preceding paper in terms of the dissociation of actomyosin into its components (2). This report deals with various factors influencing the clearing reaction and the accompanying changes in adenosine triphosphatase activity. Adenosine triphos...