Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.1 (adenylate cyclase)
 19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autoantibodies which block the binding of parathyroid hormone to membrane receptors for the hormone were detected in the sera (especially in the IgG fraction) of 49 out of 50 uraemic patients with secondary hyperparathyroidism (patients with high levels of C-regional parathyroid hormone). These antibodies are species-specific. Their presence in the serum in unaffected by dialysis. Inhibition of binding appears to be related to the rise in C-regional parathyroid-hormone levels and the duration of uraemia. The production of cyclic adenosine monophosphate by parathyroid-hormone-stimulated adenyl cyclase was reduced by the blocking antibodies. The findings show that secondary hyperparathyrodism in uraemia is another example of a receptor-antibody disease, but it is not known whether the antibodies act by modifying the affinity of the receptors for the hormone or by reducing the concentration of receptors available.
 ...
PMID:Autoantibodies to parathyroid hormone receptor. 8 34

An immunohistofluorescence procedure for detecting prostaglandin-forming cyclooxygenase has been used to localize the enzyme in the renal cortex of the cow, guinea pig, rabbit, rat, and sheep. Cyclooxygenase antigenicity was found in endothelial cells lining all arteries and arterioles and in cortical collecting tubules in each species examined. The enzyme was also detected in epithelial cells of Bowman's capsule in the rabbit and in mesangial cells in both ovine and bovine glomerular tufts. That prostaglandins can be formed in renal resistance vessels suggests that it is the synthesis occurring in these vessels which is responsible for the effects of prostaglandins on renal blood flow. Of further note is the correlation that exists between the location of the cyclooxygenase and that of the antidiuretic hormone-responsive adenyl cyclase in the distal nephron.
 ...
PMID:Immunohistochemical localization of the prostaglandin-forming cyclooxygenase in renal cortex. 10 39

Following the initiation of development, amoebae of Dictyostelium discoideum aggregate chemotactically toward cyclic AMP (cAMP). Adenyl cyclase, cAMP phosphodiesterase, and cAMP binding sites all increase 20--40 fold during the first few hours of development. It has been shown that addition of 1 mM EDTA and 5 mM MgCl2 accelerates the aggregation process. Likewise, the calcium ionophore, A23187, leads to precocious aggregation while 4 X 10(-5) M progesterone considerably delays it. These treatments have now been shown to result in increased accumulation of adenyl cyclase in the case of EDTA and Mg2+ or the ionophore and greatly decreased accumulation in the case of the steroid. Treatment with EDTA and Mg2+ or the ionophore has been shown not only to accelerate aggregation in wild-type amoebae but to overcome complete blocks to aggregation in certain mutant strains. We have found that addition of Mn2+ will also permit aggregation of mutant cells otherwise unable to aggregate. This divalent ion, unlike EDTA and Mg2+ or the ionophore, was shown to directly stimulate adenyl cyclase. Calcium ions were also found to affect the enzyme such that at Ca2+ concentrations found within the cells the great majority of the activity is inhibited. Manganese ions can overcome the inhibition by Ca2+. These findings show that conditions which stimulate aggregation result in increased activity of adenyl cyclase either by increased accumulation of the enzyme or by increased activity of the available enzyme, and support the proposed central role of adenyl cyclase in aggregation.
 ...
PMID:The effect of divalent cations on aggregation of Dictyostelium discoideum. 10 68

It has been found that the enterotoxin (choleragen) of Vibrio cholerae, strain 569B, can interfere with Phytohemagglutinin-P, pokeweed mitogen and concanavalin A stimulation of human peripheral blood leukocytes. The viability of cultured cells was not affected by the toxin. The toxin does not interfere with stimulation by direct competition for mitogen receptor sites. The ability of choleragen to inhibit stimulation by mitogens declines with time after initiation of stimulation. The biologically inactive, spontaneously formed, derivative of choleragen, choleragemoid, did not inhibit mitogen stimulation. However, choleragenoid did block the inhibition of stimulation caused by choleragen. Choleragenoid did not block inhibition of mitogen stimulation by a lymphocyte chalone preparation indicating that a different mechanism may be involved with the chalone. Since the diverse biological effects of choleragen are all believed to result from its interaction with cell membrane receptors followed by activation of adenyl cyclase, the results add to evidence which suggests that increases in the intracellular concentrations of 3',5'-adenosine cyclic monophosphate diminishes the mitotic activity of cells.
 ...
PMID:Inhibition of mitogen stimulation of human peripheral blood leukocytes by Vibrio cholerae enterotoxin. 12 58

All the known acute actions of insulin are based on the reaction of insulin with specific insulin receptors in the cell membranes of the insulin-sensitive organs. The reaction of insulin with these receptors leads, through changes in the membrane structure, to changes in the permeability of the cell membrane, the activity of the normal membrane K+/Na+ATPase and adenyl cyclase. From this results the multiplicity of acute insulin effects on numerous metabolic quantities, following a kind of intensifier system. Under physiological conditions, the effect of insulin on the liver metabolism plays the central role for the maintenance of blood sugar homeostasis.
 ...
PMID:[The mechanism of the acute action of insulin (author's transl)]. 12 20

Total and specific activity of cardiac NaK-ATPase (EC 3.6.1.3) in the rat varied parallel with the thyroid state. The functional state of the thyroid altered the number of NaK-ATPase molecules in the cell; the catalytic activity (turnover number) of individual enzyme molecules did not change. Sensitivity of NaK-ATPase to its specific inhibitor, ouabain, (as estimated from the half-maximal inhibitory concentration of ouabain) was lower in hypothyroidism but remained unchanged in hyperthyroidism relative to the euthyroid state. Action of thyroid hormones appeared to be selective for NaK-ATPase as shown by the behavior of another enzyme of the sarcolemma, adenyl cyclase. Adenyl cyclase of the heart was not affected by hyperthyroidism but was significantly elevated in hypothyroidism relative to euthyroid controls.
 ...
PMID:Alterations of cardiac NaK-ATPase by the thyroid state in the rat. 14 50

Platelets were examined to enable a simultaneous investigation to be made of indolylamine and electrolyte metabolism in affective disorder. No significant differences were detected in either platelet membrane ATPase or adenyl cyclase specific activity in any of the groups of patients studied, when compared with appropriate controls. A reduced Vmax and y for the 5-hydroxy-tryptamine uptake process into platelets was observed in both unipolar and bipolar depressed groups. The Km for this process was not significantly different in any of the patients from that found in control subjects. Lithium therapy was shown not to influence significantly any of the platelet parameters examined. It is suggested that membrane enzyme changes found in some peripheral cells in patients suffering from affective disorder, i.e. reduced Na+ + K+ - ATPase activity in erythrocytes in depression, is not common to all peripheral cells and may or may not reflect central nervous system changes.
 ...
PMID:Studies on human blood platelets in affective disorder. 15 82

Two cell culture systems were used in a study of the biological properties of several bacterial enterotoxins in vitro. By means of one model, in which HeLa cell monolayers were used, cytotoxic effects, interms of detachment of cells from a glass surface due to cell death, were assayed. By means of the second model, activation of the adenyl cyclase-cyclic adenosine 3', 5'-monophosphate (AMP) system, in terms of increased steroidogenesis by Y-1 adrenal cells (an effect which we have termed cytotonic), was assayed. None of the four toxins manifested both properties. Rather there was a clear segregation into two cytotoxic enterotoxins (Shigella dysenteriae type 1 and Clostridium perfingens) and two cytotonic products (Vibrio cholerae and Escherichia coli). These data raise the possibility that some enterotoxins may not interact with the adenyl cyclase-cyclic AMP system; this possibility has also been suggested by studies of the toxin of S. dysenteriae type 1 in the rabbit small bowel. These cell culture systems may therefore serve as convenient models for the study of the mechanism of action of both classes of enterotoxin.
 ...
PMID:Classification of enterotoxins on the basis of activity in cell culture. 16 26

1. Cyclic adenosine 3',5'-monophosphate and N-6-2'-O-dibutyryl cyclic adenosine 3',5'-monophosphate decrease the initial entry rate and the steady-state uptake of p-aminohippurate and uric acid by rabbit kidney cortex slices. 2. N-6-2'-O-Dibutyryl adenosine 3'-5'-monophosphate inhibits the tubular transport of p-aminohippurate competitively. 3. Isoproterenol, known to increase cyclic nucleotide concentration of the cortical tubules by activation of adenyl cyclase, decreases p-aminohippurate transport. Antidiuretic hormone which is known to stimulate only medullary adenyl cyclase has no effect on p-amino-hippurate uptake by cortical slices. 4. Theophylline, which inhibits cyclic nucleotide phosphodiesterase and, therefore, enhances the cellular accumulation of endogenous cyclic nucleotide, depresses p-aminohippurate transport.
 ...
PMID:Inhibition by cyclic AMP and dibutyryl cyclic AMP of transport of organic acids in kidney cortex. 16 97

The effect of hypothyroidism on the noradrenaline-induced accumulation of 3H-cyclic-AMP was measured in rat epididymal adipose tissue. Adipocytes from hypothyroid animals showed a decreased response to noradrenaline 0.02-0.2 times 10-5 m, while higher concentrations of the catecholamine seemed to elicit the same response in cells obtained from euthyroid or hypothyroid animals. The diminished sensitivity to noradrenaline was unaltered after the addition of phentolamine. It is suggested that thyroid hormones modulate the catecholamine-induced lipolytic response at least partly through the adenyl cyclase cyclic-AMP system.
 ...
PMID:Accumulation of cyclic AMP in hypothyroidism. Decreased sensitivity to norepinephrine in rat adipocytes. 16 63


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