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Dose-related alterations in the levels of prostaglandins (PGF2 alpha and PGE) and thromboxane B2 (TxB2) were observed in the urine of unanesthetized rats following whole-body gamma radiation. Exposure doses of 100 and 900 rads resulted in significant changes in urinary levels of these cyclooxygenase products. These findings suggest the potential use of(More)
To investigate the role of the Ca2+-binding protein calmodulin on histamine release in the rat peritoneal mast cell, we exposed cells to exogenous calmodulin in the presence of a variety of histamine secretagogues. Histamine release stimulated by compound 48/80, polymyxin B and ionophore A23187 was inhibited while concanavalin A-stimulated release was not(More)
Circadian rhythms in noradrenergic (NE) and dopaminergic (DA) metabolites and in cyclic nucleotide production were measured in discrete regions of rat brain. A circadian rhythm was found in the concentration of the NE metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG), in the hippocampus. No MHPG rhythm was found in frontal, cingulate, parietal, piriform,(More)
A previous finding from our laboratory, that a single dose of ethanol depletes cerebellar cyclic guanosine 3':5'-monophosphate (cGMP), has now been extended to an investigation of the effects of acute and chronic ethanol treatment of cGMP levels in six areas of the rat brain. Rats were either gavaged with a single dose of ethanol (6g/kg) or rendered(More)
Single doses of ethanol a severe depletion (95 percent) of cerebellar guanosine 3',5' -cyclic monophosphate (cyclic GMP) within 1 hour after administration. The degree of this depletion is dose-dependent and is a function of the amount of ethanol in the blood. Interactions between ethanol and cyclic GMP may account for some of the intoxicating properties of(More)
Diamine oxidase (DAO; EC activity was measured in plasma and in ileal tissue homogenates prepared from male Sprague-Dawley rats euthanized at 1-15 days after acute whole-body irradiation with 14.5-MeV electrons. Animals irradiated with 1 Gy showed no diminution in plasma and ileal DAO activities through Day 13 relative to nonirradiated controls.(More)
Gamma-irradiation, glucocorticoid hormones, and calcium ionophores stimulate a suicide process in thymocytes, known as apoptosis or programmed cell death, that involves internucleosomal DNA fragmentation by a Ca(2+)- and Mg(2+)-dependent nuclear endonuclease. In this study we report that N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) blocked DNA(More)
The kinetics of Ca2+ uptake and efflux have been measured in rat peritoneal mast cells stimulated with compound 48/80 using rapid mixing and a silicone oil centrifugation technique. Responses at one-second time intervals were resolved beginning as early as three seconds after initial stimulation. The results clearly demonstrate that Ca2+ uptake occurs after(More)