Topic
Cyclase
About: Cyclase is a research topic. Over the lifetime, 10162 publications have been published within this topic receiving 388566 citations.
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TL;DR: The purification procedure involved three sequential chromatography steps on hydroxylapatite, immobilized Cu++ and immobilized anti-CD38 monoclonal antibody resins, which yielded a single 46 kDa protein displaying all three enzymatic activities.
282 citations
TL;DR: The pigeon erythrocyte was chosen for the present investigation because of its relatively simple intracellular structure and because it provided a uniformity of cell type not found in more organized tissues, where blood vessels, connective tissue, and a multiplicity of cell types occur.
282 citations
TL;DR: A catecholamine-sensitive adenylate cyclase system is present in homogenates of both calf and rat retinas, and it is proposed that dopamine is the major activator of a retinalAdenylates cyclase, and that this activation is related to its role as a neurotransmitter.
Abstract: A catecholamine-sensitive adenylate cyclase system is present in homogenates of both calf and rat retinas. Dopamine is a more potent activator of the bovine enzyme than is norepinephrine or epinephrine. Cyclic AMP concentrations in intact bovine retina are increased by dopamine, as well as by other catecholamines, and by depolarizing agents. Studies with adrenergic blocking agents suggest that the stimulation of retinal adenylate cyclase by catecholamines cannot be clearly defined in terms of the characteristics of alpha or beta adrenergic receptors. Bovine retina also contains a protein kinase that is stimulated 20-fold by cyclic AMP. It is proposed that dopamine is the major activator of a retinal adenylate cyclase, and that this activation is related to its role as a neurotransmitter.
282 citations
Journal Article•
TL;DR: The findings of this study provide support for the view that changes in the cAMP system in the LC play a role in mediating acute opiate action as well as in underlying the development of opiate tolerance, dependence and/or withdrawal.
Abstract: Acutely, morphine and D-ala2-D-leu-enkephalin (DADLE) inhibited adenylate cyclase in vitro in locus coeruleus (LC), dorsal raphe, frontal cortex and neostriatum and the inhibition by each agonist was blocked by the opiate-receptor antagonist naloxone. Although morphine was equally efficacious in the four brain regions examined (10-15% inhibition), DADLE inhibited cyclic AMP (cAMP) production to a greater extent in cortex and striatum (20-25% inhibition). Pertussis toxin treatment in vitro significantly reduced DADLE-inhibition of adenylate cyclase in all brain areas, indicating that this opiate response is mediated by a pertussis toxin-sensitive G-protein (i.e., Gi and/or Go). Chronic (in vivo) administration of morphine pellets for 5 days, treatment known to induce opiate tolerance and dependence, increased basal, GTP- and forskolin-stimulated adenylate cyclase in the LC, but not in the other three brain regions studied. DADLE was found to inhibit cAMP production in LC in vitro to the same extent in control and morphine-treated rats, suggesting a lack of opiate receptor tolerance. The morphine-induced increase in adenylate cyclase required chronic exposure to the opiate, as shorter treatment times, namely 2 hr and 1 day, failed to produce this effect. In fact, at 2 hr a small decrease in adenylate cyclase in the LC was observed that did not appear to be due to morphine being retained in the membrane fraction. Taken together, the findings of this study provide support for the view that changes in the cAMP system in the LC play a role in mediating acute opiate action as well as in underlying the development of opiate tolerance, dependence and/or withdrawal.
281 citations
TL;DR: Ring-deleted analog C-ANF4-23 like ANF99-126 inhibited the adenylate cyclase activity in a concentration-dependent manner in rat aorta, brain striatum, anterior pituitary, and adrenal cortical membranes and inhibited cAMP levels without affecting the cGMP levels.
281 citations