Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:4.6.1.1 (adenylate cyclase)
19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adenyl cyclase activity of rat pancreatic islet membrane was increased by secretin, pancreozymin, and isoproterenol, while ACTH, glucagon, growth hormone, and insulin had no effect. Both secretin and isoproterenol activations were enhanced by prostaglandin E1 (PGE1) and GTP. Isoproterenol activation was additive with PGE1, as was that of secretin with PGE1, but only in the presence of GTP. Secretin activation in the presence of PGE1 and GTP was equivalent to NaF stimulation. Kinetic analysis indicated that secretin and GTP increased the maximum velocity of the adenyl cyclase and tended to decrease the apparent affinity of the enzyme for ATP. Glucagon activation of islet membrane adenyl cyclase was dependent upon prior treatment of the membrane preparation with EGTA and the use of inhibitors of proteolytic enzymes during the collagenase digestion phase of islet preparation. These results suggest that hormonal regulation of insulin secretion may be affected by PGE1 and guanine nucleotide modulation of the adenyl cyclase activation process.
...
PMID:Hormonal regulation of pancreatic islet adenyl cyclase. 17 51

Hydroxyurea was used to study the proliferation rate of haemopoietic stem cells (CFUs) in normal mice, after irradiation or transplantation into irradiated recipients. It was demonstrated that the proliferation rated of endogenous CFUs (endo-CFUs) and exogenous CFUs (exo-CFUs) are identical. After irradiation (650 R) the surviving endo-CFUs begin to proliferate immediately. By contrast exo-CFUs transplanted into the irradiated recipient mouse (850 R), begin to proliferate only after about 30 hr. However, injection of isoproterenol (which stimulates adenyl cyclase) or dibutyryl cyclic adenosin 3',5'-monophosphate shortly after marrow cell graft, triggers the transplanted CFUs into cell cycle as shown by an almost immediately increased sensitivity to hydroxyurea. Isoproterenol is capable of inducing DNA synthesis also in stem cells of normal mice but it takes about 20 hr before CFUs become to be increasingly sensitive to hydroxyurea.
...
PMID:Study on the proliferative state of haemopoietic stem cells (CFU). 17 46

Adenyl cyclase activity in isolated mouse liver cell membranes was stimulated two-fold by endotoxin. Furthermore, endotoxin inhibited epinephrine induction of adenyl cyclase activity, apparently through interruption of the phospholipid moiety of the enzyme complex.
...
PMID:Adenyl cyclase activity of mouse liver membranes after incubation with endotoxin and epinephrine. 17 22

The system glycocalyz - membrane bound enzymes - cAMP may be regarded as a regulatory mechanism for the control of epidermal growth. The glycocalyz of the epithelial cell membrane is obviously a receptor and accumulator for agents stimulating adenyl cyclase and other membrane-bound enzymes of energy utilisation; cAMP, on the other hand, serves as an intracellular 'mediator' between proliferative stimuli and the DNA of the keratinocytes. Numerous cytological, cytochemical, and enzymatic biochemical studies indicate that this mechanism is profoundly disturbed in psoriasis, particularly at the membrane-bound stage.
...
PMID:[Membrane defect as a basic disorder of the growth control mechanism in psoriasis pathogenetic concept and therapeutic consequences (author's transl)]. 17 49

A hydrostatic pressure of 60g/cm sq (0.85 psi) inhibits the accumulation of cAMP in cells isolated from the proliferative zone of chick-tibia epiphyseal cartilage. The following findings indicate that this effect is mediated by a translocation of calcium: (i) the pressure enhances the cellular uptake of radiocalcium; (ii) the pressure effect on cAMP can be simulated by the calcium-ionophore A23187; (iii) the effects of pressure and A23187 are non-additive; (iv) the pressure effect is not produced in the presence of ethylenebis-(oxyethylenenitrilo)-pressure effect is not produced in the presence of ethylenebis-(oxyethylenenitrilo)-tetraacetic-acid (EGTA); (v) the particulate adenyl cyclase activity of the proliferative zone is susceptible to non-competitive calcium inhibition. Throughout this study cells from the hypertrophic zone of the same epiphyses were used as controls. In these cells the calcium uptake was enhanced by pressure, but the cAMP level was not affected by pressure, A23187 or EGTA. This change in responsiveness, which accompanies the maturation of the cartilage cells, was shown to be due to a decrease in the calcium-inhibition of adenylate cyclase.
...
PMID:The role of calcium in the inhibition of cAMP accumulation in epiphyseal cartilage cells exposed to physiological pressure. 17 77

The subcellular distribution of adenyl cyclase was investigated in small intestinal epithelial cells. Enterocytes were isolated, disrupted and the resulting membranes fractionated by differential and sucrose gradient centrifugation. Separation of luminal (brush border) and contra-luminal (basolateral) plasma membrane was achieved on a discontinuous sucrose gradient. The activity of adenyl cyclase was followed during fractionation in relation to other enzymes, notably those considered as markers for luminal and contraluminal plasma membrane. The luminal membrane was identified by the membrane-bound enzymes sucrase and alkaline phosphatase and the basolateral region by (Na+ + K+)-ATPase. Enrichment of the former two enzymes in purified luminal plasma membrane was 8-fold over cells and that of (Na+ + K+)-ATPase in purified bisolateral plasma membranes was 13-fold. F--activated adenyl cyclase co-purified with (Na+ + K+)-ATPase, suggesting a common localization on the plasma membrane. The distribution of K+-stimulated phosphatase and 5'-nucleotidase also followed (Na+ + K+)-ATPase during fractionation.
...
PMID:The surface membrane of the small intestinal epithelial cell. I. Localization of adenyl cyclase. 17 91

Adenyl cyclase was assayed in a series of plasma membrane fractions prepared from bovine thyroids using sucrose density gradient ultracentrifugation. The activity of adenyl cyclase in the plasma membranes was found to be stimulated several-fold by antisera raised in rabbits against the plasma membranes and by purified IgG prepared from these antisera. The data indicate that the antibodies to thyroid plasma membrane manifest properties similar to those of the immunoglobulins long-acting thyroid stimulator (LATS) and human specific thyroid-stimulating immunoglobulin (HTSI) found in patients with Graves' disease. It is suggested that, in these patients, the antigen which leads to the production of LATS and HTSI is most likely situated in the thyroid plasma membrane.
...
PMID:Activation of thyroid adenyl cyclase by antisera to thyroid plasma membrane preparations. 17 89

Levels of cyclic adenosine monophosphate (AMP) in the basilar artery and in circulating blood of cats were determined after the production of spasm by topical application of blood to the vessel and following treatment with agents known to alter cyclic AMP. Isoproterenol, known to stimulate adenyl cyclase, and aminophylline, a phosphodiesterase inhibitor, were studied alone and in combination. Cyclic AMP of the basilar artery fell from a mean control value of 43 to 26 pmoles per milligram of protein following the production of vasospasm. Intravenous administration of isoproterenol alone and in combination with aminophylline produced dilatation of the basilar artery, which was associated with a marked rise in the cyclic AMP concentration in the vessel. The finding that cerebral vasospasm is associated with a fall and vasodilation with a rise in cyclic AMP concentration supports the hypothesis of an active role for cyclic nucleotides in the regulation of cerebrovascular smooth muscle tone.
...
PMID:Experimental alterations in cyclic adenosine monophosphate concentrations in the cat basilar artery. 18 Apr 56

Adenosine triphosphatase (ATPase) activity in erythrocyte membranes from patients with Duchenne dystrophy was inhibited by ouabain less than in normal individuals in assay systems containing high or low contents of salt. Epinephrine and cyclic adenosine monophosphate increased total ATPase activity in all samples, and epinephrine restored ouabain sensitivity to the Duchenne membranes. Basal adenyl cyclase activity in about twice that of controls. Epinephrine stimulated adenyl cyclase activity of normal membranes two to three times, but did not stimulate the enzyme in Duchenne membranes. These differences may reflect a genetic abnormality of the membrane.
...
PMID:Biochemical abnormalities of erythrocyte membranes in Duchenne dystrophy. Adenosine triphosphatase and adenyl cyclase. 18 Sep 37

Specific binding of human chorionic gonadotropin (hCG), and the hCG-sensitive adenyl cyclase of granulosa cells from small (1-2 mm), medium (3-5 mm), and large (6-12 mm) porcine ovarian follicles have been studied. The number of hCG-binding sites per cell (n) increases during follicle maturation without a change in the binding affinity. The values for n were 300-400 for small, 1,000-1,600 for medium, and 8,200-10,000 for large-follicle cells. The dissociation constant is 2.4 X 10(-10)M for all cells. hCG-sensitive adenyl cyclase was demonstrated in porcine granulosa cells. The adenyl cyclase system of granulosa cells becomes increasingly responsive to hCG stimulation during follicle development. Maximal adenyl cyclase activation by hCG (1 mug/ml) was 240, 750, and 7,000 molecules of cyclic AMP formed/sec/cell, respectively, for small, medium, and large follicle cell. The concentration of hCG giving half-maximal stimulation (1.0 X 10(-9)M) was similar for both large and medium follicle cells. It is concluded that: 1) an increase in hCG receptor sites per cell occurs during maturation of the porcine ovarian follicle without change of binding affinity, and 2) the increase in the number of hCG receptors correlates well with hCG-sensitive adenyl cyclase activity during follicle development.
...
PMID:The porcine ovarian follicle: III. Development of chorionic gonadotropin receptors associated with increase in adenyl cyclase activity during follicle maturation. 18 Dec 40


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---