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)

Histochemical staining of adenyl cyclase was performed in muscle specimens. Adenylyl imidodiphosphate (AMP-PNP) was used as the reaction substrate and strontium was used as the capture ion for the liberated phosphate. Staining appeared in the vascular structures between muscle fibers and between muscle fascicles. Substituting lead for strontium as the capture ion resulted in loss of the staining of small vessels between muscle fibers, while indistinct staining of larger vascular structures between muscle fascicles was preserved.
...
PMID:Use of strontium as the capture ion in adenyl cyclase histochemical staining of skeletal muscle. 618 28

The major histocompatibility complex of mice, the H-2 complex, regulates the steady-state level of adenosine cyclic 3',5'-monophosphate (cAMP) in liver. This effect of H-2 may be due to an effect on hormone binding to receptors. Here we show that liver membranes from animals of different H-2 types differ in their sensitivity to glucagon stimulation of adenylate cyclase and in the affinity of their receptors for glucagon. No H-2-associated differences are seen in basal, NaF-stimulated, or GMP-PNP-stimulated adenylate cyclase.
...
PMID:Influence of the mouse major histocompatibility complex, H-2, on liver adenylate cyclase activity and on glucagon binding to liver cell membranes. 624 75

The contractile system of rat cardiac muscle that has been made hyperpermeable by soaking the tissue in EGTA (McClellan and Winegrad. 1978. J. Gen. Physiol. 72:737-764) can be probed directly with Ca buffer from the bathing solution without significant interference from either sarcoplasmic reticulum or mitochondria on the Ca concentration. Changes in Ca-activated force are due therefore to changes in the properties of the contractile system itself and not to regulation of Ca concentration. The addition of cAMP, cGMP, and GTP, guanylyl imidodiphosphate (GMP-PNP), or epinephrine to the bath does not alter maximum Ca-activated force, but when these drugs are added with 1% nonionic detergent to the bath, contractility increases by as much as 180%. An inhibitor of phosphodiesterase must be present for the inotropic effect of cAMP but not cGMP, GTP, GMP-PNP, or epinephrine. The inotropic response to cAMP is independent of the Ca sensitivity of the contractile system, but guanine nucleotides enhance contractility only when Ca sensitivity is not high. The inotropic effect of epinephrine is inhibited to a large extent by cGMP but not by GMP-PNP. These data can be explained by a model in which contractility is enhanced by a cAMP-regulated phosphorylation that can be controlled through the beta-receptor adenylate cyclase complex in the sarcolemma. The regulation involves two reactions, one a phosphorylation and a second that occurs in the presence of detergent. Phosphorylation of neither the myosin light chain nor the inhibitory subunit of troponin appears to be involved in this mechanism for regulating contractility.
...
PMID:Cyclic nucleotide regulation of the contractile proteins in mammalian cardiac muscle. 624 20

[3H]GTP [guanosine triphosphate] and [3H]GMP-PNP [guanosine 5'-(beta, 8-imino)triphosphate, a nonmetabolized analog of GTP] have been utilized as ligands to characterize binding sites of guanine nucleotides to rat brain membranes. Binding of both [3H]GTP and [3H]GMP-PNP is saturable, with respective KD values of 0.76 and 0.42 microM. The number of binding sites for GMP-PNP (4 nmol/g) is three times greater than for GTP (1.5 nmol/g). This discrepancy is caused by rapid degradation of GTP to guanosine by brain membranes, which can be partially prevented by addition of 100 microM-ATP. The binding of [3H]guanine nucleotides is selective, with approximately equipotent inhibition by GTP, GDP, and GMP-PNP (at 0.2--1.0 microM), but no inhibition by other nucleotides at 100 microM concentrations. The bindings sites for guanine nucleotides in brain membranes appear not to be associated with microtubules, since treatments that reduce [3H]colchicine binding by 65% have no effect on [3H]GTP binding. [3H]Guanine nucleotide binding is widely distributed in various organs, with highest levels in liver and brain and lowest levels in skeletal muscle. The characteristics of these binding sites in brain show specificity properties of sites that regulate neurotransmitter receptors and adenylate cyclase.
...
PMID:Characterization of [3H]guanine nucleotide binding sites in brain membranes. 625 76

Multiple symmetric lipomatosis has been proposed to be associated with impaired catecholamine-responsiveness of hypertrophic adipose tissue at the level of beta-adrenergic receptors or adenylate cyclase respectively. We have studied the regulation of the adenylate cyclase by guanine nucleotides and adrenaline in 5 subjects suffering from multiple encapsulated lipomata. In the presence of GTP (0.1 mmol/l) basal adenylate cyclase activity averaged 0.5 +/- 0.3 nmol cAMP/mg protein/10 minutes in normal adipose tissue and 1.0 +/- 0.4 nmol cAMP/mg protein/10 minutes in hypertrophic adipose tissue respectively. The synthetic GTP-analogue GMP(PNP) (0.1 mmol/l) increased non-stimulated activity by about 100% in both tissues. Adrenaline (1 mumol/l-1 mmol/l) caused a dose-dependent increase of enzymic activity in both tissues which had a maximum of 130% above basal levels in the presence of GTP and of 300% in the presence of GMP(PNP) respectively. In one of the six subjects suffering from gluteal lipomata normal adipose tissue was obtained from the gluteal as well as the abdominal region on two occasions. Maximally effective concentrations of adrenaline (1 mmol/l) induced a 3-fold increase of enzymic activity in abdominal membranes compared with about a 1.7- and 1.75-fold increase in normal and lipomatous tissue from the gluteal region. The results show that encapsulated lipomata contain a normally reactive adenylate cyclase system.
...
PMID:Adenylate cyclase of multiple lipomata. Regional differences in adrenaline-responsiveness. 626 24

The localization of adenylate cyclase and 5'-nucleotidase activities in the follicular cells of adenomatous goiter and normal thyroid was studied by light and electron microscopy. Simultaneous biochemical measurement for both activities was carried out to confirm the histochemical findings. Adenylyl-imidodiphosphate (AMP-PNP) was used as an effective substrate for adenylate cyclase. The specificity of the adenylate cyclase reaction was also examined by adding oxalacetic acid or PCMB as an adenylate cyclase inhibitor, and by adding sodium fluoride or TSH as an adenylate cyclase stimulator to the reaction mixture. In the case of tissue from adenomatous goiter, a large amount of the reaction product of the adenylate cyclase activity was found uniformly in the apical and lateral plasma membrane and not in the basal plasma membrane. In the cases of normal thyroid, a small amount of the reaction product of adenylate cyclase activity was demonstrated, and only in the lateral plasma membrane of the follicular cells. On the otherhand, the histochemical localization of 5'-nucleotidase activity was the same in adenomatous goiter and normal thyroid. The reaction product of 5'-nucleotidase activity was found predominantly in the apical plasma membrane of the follicular cells. The biochemical findings indicated that the activity of adenylate cyclase per gram tissue was approximately 2 times higher in the case of adenomatous goiter than that in the case of normal thyroid, while the 5'-nucleotidase activity in adenomatous goiter was in slightly higher level than in normal thyroid. Thus the histochemically demonstrable amount of adenylate cyclase and 5'-nucleotidase reflected the activity levels measured biochemically. The lack of demonstrable adenylate cyclase activity in the basal plasma membrane suggests the possibility that this structure may not play any important role in TSH reception.
...
PMID:Localization of adenylate cyclase and 5'-nucleotidase activities in human thyroid follicular cells. 628 89

The aim of this study was to determine whether steroidogenesis occurs in human immature oocytes aspirated from follicles during gynecologic laparotomy. delta 5-3 beta-Hydroxysteroid dehydrogenase (delta 5-3 beta-HSD) and 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activities were detected by Dickmann and Dey's reaction medium consisting of 1.8 mg substrate (pregnenolone or 17 beta-estradiol [E2]), 4 mg nicotinamide-adenine dinucleotide, 2 mg nitro-blue tetrazolium, 10 ml 0.1 M phosphate buffer. The activity of adenylate cyclase was examined by ultrastructural-cytochemical study using 5'-adenylyl-imidodiphosphate (AMP-PNP) as a substrate in Vorbrodt's medium of 0.005 M AMP-PNP, 0.001 M MgCl2, 0.02 M SrCl2, 0.01 M NaF, 0.002 M theophylline, 0.01 M Tris-HCl. Furthermore, in indirect immunofluorescence study, the presence of endogenous progesterone and E2 and the activity of delta 5-3 beta-HSD were demonstrated. The results suggest that steroidogenesis, through the adenylate cyclase-cyclic adenosine 3':5'-monophosphate system, in human oocytes may play some important role in oocyte maturation, fertilization, and early embryonic development. The implication of steroid-producing activities of the human oocytes for cytoplasmic maturation is discussed.
...
PMID:Cytochemical study of steroid-producing activities of human oocytes. 630 92

The ultrastructural localization of adenylate cyclase activity has been investigated in unfixed guinea-pig peritoneal macrophages in different physiological states (such as suspension, adhesion and phagocytosis) using a medium containing 5'-adenylyl-imidodiphosphate (AMP-PNP) as the substrate. Adenylate cyclase activity was observed in cytoplasmic vacuoles of macrophages in suspension; in the perinuclear space, endoplasmic reticulum, Golgi complex and pseudopods of adherent macrophages; and surrounding phagocytosed polystyrene particles. The activity was inhibited by Alloxan added to the incubation medium and no staining was observed when AMP-PNP was omitted from the medium. The segregation of this enzyme to phagocytic vacuoles and pseudopods may have significant implications in understanding cyclic nucleotide function in adhesion and phagocytosis.
...
PMID:Differences of adenylate cyclase localization in guinea-pig peritoneal macrophages under different physiological conditions: an ultracytochemical study. 662 54

The distribution of adenylate cyclase in testis, by means of a specific substrate adenylyl-imidodiphosphate (AMP-PNP), has been determined. Membrane-associated reaction products, indicative of adenylate cyclase activity, are localized by a complete cytochemical medium (containing 10 mM NaF) at the level of the basal compartment of the seminiferous epithelium, on the basal surface of Sertoli cells, and on adjacent plasma membranes of Sertoli cells and spermatogonial cells. At the level of the adluminal compartment, reaction products were found on adjacent plasma membranes of Sertoli cells and early or elongated spermatids. Adenylate cyclase reaction products are detectable by a basal incubation medium (without 10 mM NaF) only in the adluminal compartment on the spermatid plasma membranes.
...
PMID:Cytochemical study on the distribution of adenylate cyclase in guinea pig testis. 667 Jul 58

To show adenylate cyclase (AC) activity in rat calvaria, it is necessary first to decalcify the specimen. In hard tissues, several enzymes (adenosine triphosphatase (ATPase), alkaline phosphatase (APase), adenylate cyclase (AC) and perhaps pyrophosphatase (PPiase) are able to degrade adenosine triphosphate (ATP). The presence of sodium fluoride (NaF) in the incubation medium reduces the quantity of precipitate formed, compared to that observed using a NaF-free incubation medium. Levamisole, used under the same conditions, gives similar results. Possibly NaF inhibits pyrophosphohydrolase and/or phosphatases which mask the AC activity. Adenylylimidophosphate (AMP-PNP), which is a specific AC substrate, confirms the results obtained with ATP. AC activity is demonstrated cytochemically in the osteoblast and preosteoblast membranes, at the junction between two osteoblasts and along the cytoplasmic processes of the osteoblast which penetrate into the osteoid matrix. The osteocytes never show a precipitate, except those which present some osteoblastic features and then only on the membrane facing the osteogenic layer. An intracellular reaction is also evident and is discussed. Parathyroid hormone (PTH) does not reveal new sites of AC activity but increases the quantity of precipitate observed.
...
PMID:An attempt at localizing adenylate cyclase in rat calvaria. Influence of sodium fluoride and parathyroid hormone. 700 93


<< Previous 1 2 3 4 5 6 Next >>

---