Mol Cell Endocrinol
May 1988
6-Methoxybenzoxazolinone (MBOA) is a compound isolated from grasses which has gonadotropic effects in a variety of animals. The weak beta-adrenergic agonist character of MBOA is shown by its in vitro stimulation of adenylate cyclase from several tissues. Tritiated MBOA bound specifically to particulate fractions from uterus is also displaced by alpha- and beta-adrenergic compounds.
View Article and Find Full Text PDFAdenylate cyclase (AC) in pineal particulate fractions from rabbit, rat, cow, and the vole Microtus montanus was stimulated by L-norepinephrine (NE) and L-isoproterenol (ISO). NE stimulation of rabbit and bovine pineal AC was biphasic, with a plateau between 0.01 microM and 1.
View Article and Find Full Text PDFBiochem Biophys Res Commun
August 1986
Binding of the beta-adrenergic ligands [3H]dihydroalprenolol and [125I]cyanopindolol to pineal particulate fractions was increased 1- to 3.5-fold by addition of low concentrations of melatonin, alpha-adrenergic agonists, or alpha-adrenergic antagonists. Minimum concentrations of melatonin or alpha-adrenergic compounds which increased beta-adrenergic binding were between 1 pM and 0.
View Article and Find Full Text PDFJ Cyclic Nucleotide Protein Phosphor Res
March 1986
Membranes from neuroblastoma X glioma NG108-15 hybrid cells were purified by equilibrium centrifugation on continuous and discontinuous gradients of sorbitol, using homogenates of cells which were pretreated with concanavalin A to increase membrane density. Adenylate cyclase was purified 24-fold in a heavy (H) membrane fraction from discontinuous gradients, opiate-stimulated guanosine-5'-triphosphatase was purified 3-fold, and opiate binding to receptors was increased 10-fold in this fraction. The relative purification of this membrane fraction is also verified by the fact that it contains a single protein (Mr = 58,000) which is covalently labeled by a reactive opiate analog (Klee, W.
View Article and Find Full Text PDFMol Cell Endocrinol
October 1983
Some metabolic effects of prostaglandins have been related to their alteration of adenosine-3',5'-monophosphate (cyclic AMP) metabolism in different tissues. Prostaglandins E1 and E2 stimulate liver adenylate cyclase in vitro, but conflicting reports have been made about metabolic changes caused by E prostaglandins in hepatic tissue. We have attempted to resolve these issues by comparing the effects of PGE1 with those of glucagon using broken-cell homogenates, intact hepatocytes, liver slices and perfused liver.
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