Extracts of vegetative cells of Blastocladiella emersonii contain 5% or less of the cyclic AMP phosphodiesterase activity in zoospore extracts. This difference in activity could be accounted for entirely by an increase in the differential rate of phosphodiesterase synthesis during sporulation, beginning after a lag period of about 60 min and extending for at least an additional 90 min into the ...

Dibutyryl cyclic AMP was administered to 2 patients with severe congestive heart failure. After an intravenous drip infusion of dibutyryl cyclic AMP (300 mg/40 min), marked diuresis and mild improvement of the patients' physical activity occurred. The cardiac index increased and both systemic vascular resistance and pulmonary capillary wedge pressure decreased. Blood glucose and plasma insulin ...

We examined the patterns of cyclic AMP-dependent protein phosphorylation in membranes prepared from rat cortical synaptosomes following gel electrophoresis and autoradiography. We determined the optimum pH (6.2), time (20 s), Mg2+ concentration (10 mM) and cyclic AMP concentration (5 microM) for the reaction. We also found that the detergents Triton X-100 and gramicidin S enhanced cyclic AMP-de...

Stereo-specific perturbation of the IgE-receptor (shown in previous studies) produces a monophasic rise in cyclic AMP that peaks at 15 s and a depletion of cyclic AMP-dependent protein kinase that plateaus at 30-60 s. The previously observed linear relationship between the attenuation in the monophasic rise in cyclic AMP and the quantity of mediator release in the presence of incremental concen...

Although the peptidergic bag cell neurons of Aplysia are ordinarily silent, they respond to brief electrical stimulation by producing an afterdischarge of about 30 min duration. This afterdischarge is followed by a refractory period lasting many hours during which electrical stimulation either fails to initiate afterdischarges or produces discharges of much shorter duration. Previous work has d...

1. Both permanent and transient catabolite repression of beta-galactosidase synthesis in Escherichia coli are abolished by 5mm-3':5'-cyclic-AMP when elicited by glucose, but not when caused by a mixture of glucose, glucose 6-phosphate, gluconate and casein hydrolysate (casamino acids). 2. Glucose uptake is slightly increased by 3':5'-cyclic-AMP. 3. No significant effects of the nucleotide were ...

We reevaluated the use of 32PO4 pulse-chases for analyzing mRNA decay rates in late-developing Dictyostelium cells. We found that completely effective PO4 chases could not be obtained in developing cells and that, as a consequence, the decay rates exhibited by some mRNAs were influenced by the rates at which they were transcribed. In developing cells disaggregated in the presence of cyclic AMP,...

The concentration of myocardial cyclic AMP was measured in 9 dogs by radioimmunoassay after the administration of aminophylline. Fourteen dogs served as control. The concentration of cyclic AMP in the left ventricle was the highest and the lowest value was obtained in the right atrium in the control dogs. Ventricular fibrillations were induced immediately after the injection of 30 mg/Kg aminoph...

A number of hormones and neurohormones have been shown to exert their effect on their target tissues by altering the intracellular level of 3'5'-cyelic AM\IP.1 Among the processes mediated by cyclic AMP is the secretion of macromolecules by various endocrine and exocrine glands.2-5 Of particular interest to investigators studying the exocrine pancreas was the observation of Schramm and his co-w...

A newly discovered cyclic AMP-independent protein kinase, which catalyzes the total conversion of glycogen synthase from the I- to the D-form, has been isolated from rabbit skeletal muscle. This enzyme, designated glycogen synthase kinase, is separable from cyclic AMP-dependent protein kinase by column chromatography on phosphocellulose. Synthase kinase and cyclic AMP-dependent protein kinase a...