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)

Piflutixol, 6-fluoro-9-[3-(4-(2-hydroxyethyl)piperidino)propylidene]-2-trifluoromethyl-thioxanthene, has been shown to have pronounced neuroleptic properties. It is a very potent inhibitor of methylphenidate-induced stereotypies in mice, amphetamine and apomorphine-induced stereotypies in rats, apomorphine-induced stereotypies and vomiting in dogs. Furthermore piflutixol causes cataleptic reaction in small doses and inhibits conditioned avoidance reaction in rats. The compound is equally potent orally and parenterally and has a prolonged effect. Piflutixol has up to the present proved to be the most potent inhibitor of dopamine-stimulated adenylate cyclase in rat striatum in vitro. Piflutixol has a stron sedative effect (inhibition of spontaneous motor activity, induction of ptosis and potentiation of barbiturate anaesthesia) and in addition inhibits reticular arousal reaction in very low doses. Thus piflutixol constitutes a unique combination of potent anti-stereotyped activity with potent sedative effects. This means that piflutixol may prove to be a low-dose basic neuroleptic with long duration of action.
 ...
PMID:The pharmacology of a new potent, long acting neuroleptic, piflutixol. 57 63

N6-Substituted 9-methyladenines are potent antagonists of the activation of A1 adenosine receptors. The present study assessed the effect of N6 and N-9 substituents on the binding of adenines to the A1 and A2 receptors, respectively, of rat brain cortex and striatum and also on the antagonism of the A2 receptor mediated stimulation of the adenylate cyclase of PC12 cells by N-ethyladenosine-5'-uronamide. The potency ranking of 9-substituted adenines varied directly with the hydrophobicity of the substituent: cyclopentyl greater than phenyl greater than tetrahydrofuryl greater than ethyl greater than methyl greater than 2-hydroxyethyl. The 9-substituted adenines showed little selectivity for either receptor and the R enantiomer of N6-(1-phenyl-2-propyl)-9-methyladenine was only 4-fold more potent than the S enantiomer at the A1 receptor. An N6-cyclopentyl substituent increased potency at the A1 receptor and decreased potency at the A2 receptor, resulting in selectivity for the A1 receptor of up to 39-fold. The N6-cyclopentyl group completely overshadowed the effect of the hydrophobicity of the 9-substituent. A 2-chloro substituent did not alter the potency of an N6-substituted 9-methyladenine.
 ...
PMID:N6,9-disubstituted adenines: potent, selective antagonists at the A1 adenosine receptor. 189 5

The beta adrenergic activation of adenylate cyclase was examined in membrane homogenates of rat interscapular brown adipose tissue (IBAT). In control membranes, isoproterenol and norepinephrine (NE) stimulated adenylate cyclase with activation constants of about 20 and 300 nM, respectively. Exposure of rats to 4 degrees C for 3 days increased the maximal stimulation of adenylate cyclase to these agonists but did not alter the respective activation constants. The beta 1-selective antagonist 1-(2-cyanophenoxy)-3-beta-(3-phenylureido)ethylamino-2-pr opa nol blocked isoproterenol stimulation of adenylate cyclase in control and cold-exposed membranes at a concentration 100 times lower than did the beta 2-selective antagonist erythro-dl-1-(7-methylindan-4-yloxy)-3-isopropylaminobuta n-2-ol. These data indicate that typical adrenergic agonists stimulate IBAT adenylate cyclase via beta 1 receptors. (R*,R*)-4-[2-[2 [9 3-chlorophenyl)-2-hydroxyethyl]amino)propyl) phenyl]phenoxyacetic acid (BRL 37344), an atypical agonist with activity at the beta 3 receptor, stimulated adenylate cyclase in control membranes with an activation constant of approximately 700 nM. Membranes of cold-exposed rats exhibited a high affinity response to BRL 37344 similar to that seen in control membranes and, in addition, a low affinity response. BRL 37344 stimulation of adenylate cyclase was unaffected by 1-(2-cyanophenoxy)-3-beta-(3-phenylureido)ethyl-amino-2-prop anol, whereas stimulation by NE or epinephrine was potently blocked.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Norepinephrine and BRL 37344 stimulate adenylate cyclase by different receptors in rat brown adipose tissue. 197 40

The N-allyl derivative (SK&F 85174) of 6-chloro-2,3,4,5-tetrahydro-1-(4-hydroxyphenyl)-1H-3-benzazepine-7,8-dio l (SK&F 82526) not only retains the exceptional D-1 agonist potency of its parent but also displays reasonably potent D-2 agonist activity, as measured by a dopamine-sensitive adenylate cyclase test and a rabbit ear artery assay, respectively. Several additional N-substituted compounds were prepared to explore the D-2/D-1 agonist relationship. The N-methyl analogue retained good D-2 agonist potency, but this substitution converted D-1 agonist activity into antagonist activity. Most other N-substituents sharply decreased D-2 agonist potency including the N-n-propyl group. This observation was surprising since the introduction of mono- or di-N-n-propyl substituent(s) is commonly linked with retention or enhancement of D-2 agonist potency in other series of dopamine agonists. The N-(2-hydroxyethyl) analogue retains about one-fourth the D-2 potency of SK&F 85174. Several synthetic methods were used to prepare these compounds. N-Allylation of a trimethoxybenzazepine followed by cleavage of the methyl ethers with boron tribromide was the preferred method. Other methods used were direct alkylation of the trihydroxy secondary amine, i.e., SK&F 82526, and an acylation-amide reduction-cleavage method.
 ...
PMID:Dopamine receptor agonists: 3-allyl-6-chloro-2,3,4,5-tetrahydro- 1-(4-hydroxyphenyl)-1H-3-benzazepine-7,8-diol and a series of related 3-benzazepines. 287 Nov 92

1. A number of centrally acting hypotensive agents and other ligands with high affinity for 5-hydroxytryptamine1A (5-HT1A) recognition sites have been tested on forskolin-stimulated adenylate cyclase activity in calf hippocampus, a functional model for 5-HT1A-receptors. 2. Concentration-dependent inhibition of forskolin-stimulated adenylate cyclase activity was elicited by the reference 5-HT1-receptor agonists (mean EC50 value, nM): 5-HT (22), 5-carboxamidotryptamine (5-CT, 3.2), 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT, 8.6), N,N-dipropyl-5-carboxamidotryptamine (DP-5-CT, 2.3), 1-[2-(4-aminophenyl)ethyl]-4-(3-trifluoromethylphenyl)-piperazine (PAPP or LY 165163, 20), 5-methoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H indole (RU 24969, 20), buspirone (65) and ipsapirone (56). Emax amounted to 18-20% inhibition for all but the latter two agonists (14%). 3. The following hypotensive agents with high affinity for 5-HT1A sites were potent agonists in this system (mean EC50 value, nM): flesinoxan (24), indorenate (99), erythro-1-(1-[2-(1,4-benzodioxan-2-yl)-2-hydroxyethyl]-4-piperidyl )- 2-benzimidazolinone (R 28935, 2.5), urapidil (390) and 5-methyl-urapidil (3.5). The first two agents were full agonists, whereas the latter three acted as partial agonists with 60-80% efficacy. 4. Metergoline and methysergide behaved as full agonists and cyanopindolol as a partial agonist with low efficacy. Spiroxatrine and 2-(2,6-dimethoxyphenoxyethyl)aminomethyl- 1,4-benzodioxane (WB 4101) which bind to 5-HT1A sites with nanomolar affinity, were agonists and inhibited potently forskolin-stimulated adenylate cyclase in calf hippocampus, showing mean EC50 values of 23 and 15 nM, respectively. Spiroxatrine and WB 4101 yielded 90% and 50% efficacy, respectively. 5. Spiperone and methiothepin (each 1 microM) caused rightward shifts of the concentration-effect curve to 8-OH-DPAT, without loss of the maximal effect, as did the partial agonist cyanopindolol (0.1 microM) and the (-)- and (+)-enantiomers of pindolol (1 microM and 0.1 mM, respectively). 6. There was an excellent correlation (r = 0.90, P = 0.0001) between the pEC50 values (ranging from 6.4 to 8.7) of the 19 agonists tested at adenylate cyclase and their pKD for 5-HT1A recognition sites. Apparent pKB values of antagonists at adenylate cyclase and their pKD values for 5-HT1A binding sites were also significantly correlated. 7. This study further indicates that the 5-HT1A recognition site and the 5-HT receptor mediating inhibition of adenylate cyclase in hippocampus are the same. The data show that a number of centrally acting hypotensive agents with high affinity for the 5-HT1,A site are potent agonists in this model, suggesting an involvement of central 5-HTIA-receptors in the control of blood pressure.
 ...
PMID:Centrally acting hypotensive agents with affinity for 5-HT1A binding sites inhibit forskolin-stimulated adenylate cyclase activity in calf hippocampus. 320 99

The cannabinoid receptor in brain (CB1) specifically binds delta 9-tetrahydrocannabinol, the predominant central nervous system-active component of marijuana. An eicosanoid found in brain, N-(2-hydroxyethyl)arachidonylamide (anandamide), binds to CB1 with similar affinity. This report considers structure-activity requirements for a series of novel amides and rigid hairpin conformations typified by N-(2-hydroxyethyl)prostaglandin amides, assayed with phenylmethylsulfonyl fluoride inactivation of esterases/amidases. Arachidonyl esters were 30-fold less potent than N-(2-hydroxyethyl)arachidonylamide, showing a rank order of potency of methyl = ethyl > propyl = isopropyl. Within the N-(hydroxyalkyl)arachidonylamide series, a one-carbon increase in chain length increased the potency 2-fold, but continued extension decreased affinity. Substituting the amide for the N-(2-hydroxyethyl)amide function produced a 4-fold loss of affinity. The N-(propyl)-, N-(butyl)-, and N-(benzyl)arachidonylamide derivatives exhibited a 3-fold increase, no change, and a 5-fold decrease, respectively, in affinity, compared with N-(2-hydroxyethyl)arachidonylamide. Both the methoxy ether and the formamide derivatives suffered > 20-fold loss of potency, compared with N-(2-hydroxyethyl)arachidonylamide. N-(2-Aminoethyl)arachidonylamide interacted poorly with CB1. At 100 microM, N-(2-hydroxyethyl)amide analogs of prostaglandin E2, A2, B2, and B1 failed to alter [3H]CP55940 binding to CB1. N-(2-Hydroxyethyl)arachidonylamide inhibited adenylate cyclase with lesser potency but with similar efficacy, compared with desacetyllevonantradol. Extending the length of the hydroxyalkyl moiety by one carbon increased the apparent potency by 1 order of magnitude. The N-(propyl) derivative exhibited a 5-fold greater potency than did the N-(2-hydroxyethyl) analog. It appears that the bulk and length of the moiety appended to arachidonic acid are more important determinants of affinity for CB1 than is hydrogen-bonding capability.
 ...
PMID:Cannabinoid receptor binding and agonist activity of amides and esters of arachidonic acid. 793 33

Endotoxin produces a variety of biological effects on different cell types, such as priming of neutrophils and macrophages, which then release a number of important mediators of endotoxin-induced lung injury. However, the specific mechanism by which endotoxin initiates its cascade of pathophysiological events in the lung has not been described. Both A1 adenosine receptor activation and endotoxin induce the release of thromboxane A2 from the lung and inhibit adenylate cyclase. By acting on A1 adenosine receptors, adenosine promotes neutrophil chemotaxis and adherence to endothelial cells. We hypothesized that A1 adenosine receptor activation is essential to endotoxin-induced lung injury, and we used the highly selective A1-adenosine receptor antagonists, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) and 8-benzyl-7,[2-[ethyl(2-hydroxyethyl)amino]-ethyl] theophylline (bamiphylline), to investigate whether selective blocking of the A1 adenosine receptor would prevent endotoxin-induced acute lung injury. An intralobar arterial infusion of endotoxin (15 mg/kg) into the left lower lobe of the lung in intact-chest, spontaneously breathing cats produced lung injury characterized by the presence of neutrophils, macrophages, and red blood cells (RBCs) in alveoli, and alveolar edema and necrosis. Lower doses of endotoxin (5 or 10 mg/kg) produced less severe and dose-dependent lung injury. Endotoxin (15 mg/kg)-induced alveolar injury was blocked in a highly significant manner by A1-adenosine receptor antagonists, DPCPX and bamiphylline. An intravenous bolus of DPCPX 30 min before endotoxin infusion or a continuous intravenous infusion of bamiphylline 30 min before, during, and 30 min after endotoxin reduced the percent injured alveoli (defined as the presence of 2 or more inflammatory cells or RBCs, or edematous fluid) from 57 +/- 31% (endotoxin 15 mg/kg) to 9 +/- 1% (DPCPX) or 21 +/- 14% (bamiphylline), which were not significantly different from control (1-h perfusion only) (4 +/- 1%) (P < 0.05). These data represent the first evidence that A1-adenosine receptor antagonism blocks the capacity of endotoxin to cause lung injury. A1-adenosine receptor antagonists may be useful in preventing adult respiratory distress syndrome associated with septicemia.
 ...
PMID:A1-adenosine receptor antagonists block endotoxin-induced lung injury. 912 87

To compare the inhibition of uterine contractility mediated by beta-adrenoceptors and 5-HT(7) receptors, the effects of catecholamines and 5-HT on spontaneous contractions were examined in longitudinal and circular muscles isolated from three different regions (cornu, corpus and cervix) of the non-pregnant proestrus porcine uterus. In addition, the distribution of beta-adrenoceptors between muscle layers was characterized by means of adenylate cyclase activity assay, cyclic AMP assay and [(3)H]dihydroalprenolol binding studies. In the cornu, isoprenaline, adrenaline and noradrenaline inhibited the spontaneous contraction of longitudinal and circular muscles but longitudinal muscle was more sensitive to catecholamines than was circular muscle. The inhibitory response to isoprenaline was antagonized by propranolol (300 nM) or (+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol (ICI 118,551; 100 nM). The rank order of potency was isoprenaline > or =adrenaline > noradrenaline. The beta(2)-adrenoceptor-selective agonist, clenbuterol, was more potent than xamoterol (beta(1)-selective) and (+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl)amino]propyl]phenoxyacetic acid (BRL 37344; beta(3)-selective) to inhibit the spontaneous contraction of longitudinal muscles. Isoprenaline increased adenylate cyclase activity in both muscle layers, but the activity in the longitudinal muscle was greater than that in the circular muscle. Cyclic AMP production by isoprenaline was also more conspicuous in the longitudinal muscle than in the circular muscle. Although both muscle layers contained a single class of [3H]dihydroalprenolol binding sites with similar K(d) values (longitudinal muscle, 3.1+/-0.94 nM, n=4; circular muscle, 2.4+/-0.73 nM, n=4), B(max) in the longitudinal muscle (175.7+/-32.8 fmol/mg protein, n=4) was significantly higher than that in the circular muscle (53.1+/-5.1 fmol/mg protein, n=4). As previously reported [Br. J. Pharmacol. 130 (2000) 79], 5-HT also inhibited the spontaneous contraction of both muscle layers from the cornu and the 5-HT(7) receptor antagonist, 2a-[4-(4-phenyl-1,2,3,6-tetrahydropyridyl)butyl]-2a,3,4,5-tetrahydro-benzo[cd]indol-2(1H)-one (DR4004; 100 nM, n=4) blocked the 5-HT-induced inhibition of spontaneous contractions in the circular muscles, and reversed the less marked inhibition in the longitudinal muscles. In other regions of the uterus (corpus and cervix), 5-HT inhibited the spontaneous contraction of the circular muscles but contracted the longitudinal muscle strips. On the other hand, isoprenaline caused muscle layer-dependent inhibition (longitudinal muscle > circular muscle) in both regions, and the responsiveness tended to increase toward the cervix. In conclusion, beta(2)-adrenoceptors are present heterogeneously in the porcine uterus (longitudinal muscle > circular muscle) and share the inhibition of uterine contractility with 5-HT(7) receptors in a layer-dependent manner (longitudinal muscle: beta(2)-adrenoceptors, circular muscle: 5-HT(7) receptors).
 ...
PMID:5-HT(7) receptor and beta(2)-adrenoceptor share in the inhibition of porcine uterine contractility in a muscle layer-dependent manner. 1175 52

In this study, we investigated the signal transduction pathway involved in beta(3)-adrenoceptor-mediated relaxations of guinea pig gastric fundus and duodenum. In the presence of beta1- and beta2-adrenoceptor blockade, the potency (pD2 value) of catecholamines ((-)-isoprenaline, (-)-noradrenaline and (-)-adrenaline) and beta(3)-adrenoceptor agonists ((R*, R*)-(+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl)amino]propyl]phenoxyacetic acid sodium (BRL37344) and (+/-)-[4-[3-[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]-1,3-dihydro-2H-benzimidazol-2-one] hydrochloride ((+/-)-CGP12177A)) to induce relaxation was not affected by the adenylate cyclase inhibitor, 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ-22,536, 100 microM). Catecholamines induced an elevation of cyclic AMP and SQ-22,536 significantly abolished the responses of gastric fundus. However, cyclic AMP levels were unaltered by the beta3-adrenoceptor agonists in gastric fundus and by the five agonists in duodenum. Furthermore, the relaxant responses to catecholamines and to beta3-adrenoceptor agonists were unaffected by the cyclic AMP-dependent protein kinase inhibitor, N-(2-[p-bromocinnamylamino]ethyl)-5-isoquinolinesulfonamide (H-89, 10 microM) in gastric fundus. These results suggest that beta3-adrenoceptor-induced relaxation is mediated through both cyclic AMP-dependent and cyclic AMP-independent pathways in gastric fundus and through a cyclic AMP-independent pathway in duodenum.
 ...
PMID:Cyclic AMP-independent relaxation mediated by beta3-adrenoceptors on guinea pig gastrointestine. 1202 Jun 91