Effects of Adenosine Triphosphate on Ventriculoatrial Conduction

Alternate ventriculoatrial Wenckebach conduction.

Three cases are presented showing retrograde alternate Wenckebach periods. Retrograde alternate Wenckebach periods were defined as 2:1 ventriculoatrial (VA) block in which the conducted beats showed progressive prolongation of conduction (VA) time. The sequence terminates with two or three successively blocked ventricular beats. In one of the three cases the level of block was identified as bei...

Antidipsogenic effects of central adenosine-5'-triphosphate.

Besides other physiological functions, adenosine-5'-triphosphate (ATP) is also a neurotransmitter that acts on purinergic receptors. In spite of the presence of purinergic receptors in forebrain areas involved with fluid-electrolyte balance, the effect of ATP on water intake has not been investigated. Therefore, we studied the effects of intracerebroventricular (icv) injections of ATP (100, 200...

Electrophysiologic effects of adenosine-5'-triphosphate on atrioventricular reentrant tachycardia.

Studies on Adenosine Triphosphate Transphosphorylases

The isolation of the crystalline enzymes, adenosine triphosphate-creatine transphosphorylase (1) and adenosine triphosphate-adenosine 5’-phosphate transphosphorylase (2), made possible a comparative approach to the general problem of the mechanism of action of the adenosine triphosphate transphosphorylases. The present series of papers extends earlier studies from this laboratory on these enzym...

Adenosine triphosphate inhibition in myosin adenosine triphosphate systems.

Factors affecting inhibition of myosin ATPase by ATP, such as concentration of the enzyme, of ATP, and of the divalent metals, calcium and magnesium, have been studied and the results are reported here. Experiments were carried out under conditions in which no known magnesium effects occurred, so that only the effect of calcium on the nucleoside triphosphatase activity of myosin A could be qual...