Adenylate cyclase and ‘adenosine triphosphatase’ in corpus luteum

Mouse neuroblastoma adenylate cyclase. Adenosine and adenosine analogues as potent effectors of adenylate cyclase activity.

1. Intact mouse neuroblastoma NS20 cells, in the presence of cyclic adenosine 3':5'-monophosphate (cAMP) phosphodiesterase inhibitor, responded to adenosine (200 muM) and 2-chloroadenosine (200 muM) with a 20-fold increase in intracellular cAMP levels. AMP (200 muM) additions caused only a 3.5-fold cAMP level elevation. ATP, ADP, guanosine, cytidine, uridine, and guanine, all at 200 muM, had no...

Isolation of plasma membranes from bovine corpus luteum possessing adenylate cyclase, 125I-hCG binding and Na-K-ATPase activities.

Plasma membranes from bovine corpora lutea have been purified by sucrose density gradient centrifugation. The purified membranes, in addition to binding 1251-hCG, also possess hCGstimulated adenylate cyclase and Na-K-ATPase. The relative purification of 1251-hCG binding, adenylate cyclase and Na-KATPase on the basis of the specific activities in the whole homogenate were 7.8, 6.4 and 2.6, respe...

E VALUATION OF ADENYLATE CYCLASE ACTIVITY IN MITRAL VALVE PROLAPSE

The term mitral valve prolapse (MVP) is used for a particular subset of patients with hyperadrenergic dysautonomia. It occurs when part of a leaflet or both leaflets of the mitral valve extend above the plane of the atrioventricular junction during ventricular systole. The adenylate cyclase activity in MVP dys-autonomia was studied by extraction of enzyme from the erythrocytes from 62 norma...

Two distinct adenosine-sensitive sites on adenylate cyclase.

The effects of adenosine and adenosine analogs on adenylate cyclases from several tissues have been examined. Two adenosine-reactive sites have been identified: (i) the "R" site, occupancy of which usually leads to activation of cyclase and which requires integrity of the ribose ring for activity, and (ii) the "P" site, which mediates inhibition and requires integrity of the purine ring for act...

Adenosine triphosphatase and myopathy.