Stimulation of catecholamine release was studied in the isolated adrenal of the cat during retrograde perfusion. Theophylline, adenosine 3':5'-cyclic monophosphate (cyclic AMP), and dibutyryl-cyclic AMP stimulated catecholamine release in adrenal chromaffin tissue; adenosine, 2'-AMP, 3'-AMP, and 5'-AMP were ineffective. Addition of theophylline for 5-15 min had no effect on catecholamine releas...

The effect of adenosine-3',5'-cyclic monophosphate (cyclic AMP) and N(6),O(2)-dibutyryl adenosine-3',5'-cyclic monophosphate (dibutyryl cyclic AMP) on renal tubular permeability was studied by microinjection techniques in anesthetized diuretic rats. Radioactive inulin and mannitol were microinjected simultaneously into superficial proximal and distal convolutions and recovery of the isotopes wa...

Periodic activities of Dictyostelium discoideum cells involve two types of oscillations, spike-shaped and sinusoidal. Spike-shaped oscillations are accompanied by the periodic synthesis and release of cyclic AMP, and cyclic AMP-activated cyclic AMP synthesis is believed to control these oscillations. Experiments described here call into question the importance of cyclic AMP in spike-shaped osci...

Phototaxis and thermotaxis by Dictyostelium discoideum slugs on water agar were impaired by the presence in the agar of adenosine, which is a cyclic AMP receptor antagonist in aggregating amoebae. Caffeine, and presumably its analogue theophylline, inhibit cyclic AMP signalling in aggregating amoebae of D. discoideum. Both compounds perturbed slug behaviour in a similar manner to adenosine, as ...

• This review examines critically the evidence bearing on the hypothesis that the positive inotropic effects of catecholamines are mediated by intracellular cyclic adenosine monophosphate (cyclic AMP). The review is selective in several respects. For example, it does not contain extensive discussions about the biochemical actions of cyclic AMP, the enzymes regulating its synthesis and degradati...

The relationship between bradykinin (BK)-induced prostaglandin E2 (PGE2) and cyclic AMP syntheses in mouse fibrosarcoma cells (HSDM1C1) was investigated. Maximal BK-induced increases in cyclic AMP preceded increases in PGE2 production. PGE2 synthesis reached maximum at a much lower concentration of BK than cyclic AMP synthesis. Indomethacin completely inhibited BK-induced PGE2 production, but d...

• This review examines critically the evidence bearing on the hypothesis that the positive inotropic effects of catecholamines are mediated by intracellular cyclic adenosine monophosphate (cyclic AMP). The review is selective in several respects. For example, it does not contain extensive discussions about the biochemical actions of cyclic AMP, the enzymes regulating its synthesis and degradati...

Cyclic AMP and cyclic GMP were released into the growth medium of mycelia of Neurospora crassa wild-type strains St.L.74A and Em5297a and by white collar-1 and white collar-2 mutant strains. After growth for 6 days at 18 degrees C, there were 2.19 (St.L.74A), 5.83 (Em5297a), 1.38 (white collar-1), and 1.10 (white collar-2) nanomoles of cyclic AMP per gram dry weight of mycelia in the growth med...

The roles of cyclic AMP and cyclic AMP-dependent protein kinase in the contractile and metabolic responses to neural stimulation were studied in the bullfrog heart perfused in situ. The interaction of parasympathetic and sympathetic nerves in the regulation of myocardial cyclic AMP, cyclic AMP-dependent protein kinase, and phosphorylase also was studied. Stimulation of the left vagosympathetic ...

When whole urinary bladders of the toad were incubated with adenosine 3',5'-monophosphate-(3)H (cyclic AMP-(3)H) > 95% of the radioactivity could be extracted from the tissue with trichloroacetic acid (TCA). The TCA-soluble radioactivity was separable by cation-exchange (Dowex-50) chromatography into residual cyclic AMP-(3)H, 5'-AMP-(3)H, adenosine diphosphate (ADP)-(3)H and inosine-(3)H. Thus,...