Search results for "Enzyme Inhibitor"
showing 10 items of 627 documents
The influence of active secretion processes on intestinal absorption of salbutamol in the rat.
2001
Abstract Salbutamol was perfused in the small intestine of rat using a standard rat gut ‘in situ’ preparation: (1) in inhibitor-free solution at seven different concentrations (0.15, 0.29, 1.20, 5.0, 9.0, 13.0 and 18.0 mM); (2) at a 0.29 mM concentration – thought to be close to the allometric dose in man – in the presence of a non-specific enzyme inhibitor, sodium azide (0.3, 3.0 and 6.0 mM); and (3) at 0.29 mM in the presence of a selective secretion inhibitor, verapamil (10.0 and 20.0 mM). In free solution, the mixed-order rate constants, k ′ a , of salbutamol increase as the solute concentration increases until an apparent asymptotic value is reached. This could be due to the saturation…
Differential effects of nitric oxide donors on basal and electrically evoked release of acetylcholine from guinea-pig myenteric neurones
1996
1. The effects of the nitric oxide (NO) donors, 3-morpholino-sydnonimine (SIN-1), S-nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside on basal and electrically evoked release of [3H]-acetylcholine were studied in myenteric plexus longitudinal muscle preparations of the guinea-pig small intestine preincubated with [3H]-choline. 2. The NO donors concentration-dependently increased basal release of [3H]-acetylcholine. The increase in release was calcium-dependent and was prevented in the presence of tetrodotoxin. Superoxide dismutase (150 u ml-1) potentiated the effect of SIN-1. The selective inhibitor of soluble guanylyl cyclase, 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (OD…
Chronic pharmacological treatment in takotsubo cardiomyopathy.
2008
Abstract Background Takotsubo cardiomyopathy is a disorder that has been appreciated only recently. In most of reported cases, this syndrome mimes an acute myocardial infarction. Till this moment no data are available from literature about the treatment in the acute phase of this disease. Aim of the study In our multicentric experience we have retrospectively looked at the benefits of a treatment with ACE-inhibitors, beta-blockers, Aspirin and calcium channels blockers, started until the early phases of the disease and continued for 30 days, in 36 patients affected by Takotsubo cardiomyopathy. We chose as endpoint of the study the efficacy of the used drug in improving left ventricular myoc…
Inhibitory effects of indicaxanthin on mouse ileal contractility: analysis of the mechanism of action.
2011
Recently, we have showed that indicaxanthin, the yellow betalain pigment abundant in the fruit of Opuntia ficus indica, has remarkable spasmolytic effects on the intestinal contractility in vitro. Thus, the purpose of the present study was to investigate the mechanism of action underlying the observed response. We used organ bath technique to record the mechanical activity of the mouse ileum longitudinal muscle and ELISA to measure the levels of cAMP. Indicaxanthin induced inhibitory effects on spontaneous mechanical activity, which were unaffected by indomethacin, a non-selective inhibitor of cycloxygenase; 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a selective inhibitor of nitric oxide-…
Inhibition of nitric oxide synthase influences the activity of striatal neurons in the rat
2002
The activity of single units in the striatum of urethane-anesthetized rats was recorded before and after the systemic administration of 7-nitro-indazole (7-NI; 50 mg/kg intraperitoneally), a selective inhibitor of neuronal nitric oxide (NO) synthase. Two neuronal types were clearly distinguishable electrophysiologically, on the basis of either discharge frequency pattern or features of the individual spike waveform (spike duration, negative phase/total duration ratio, and negative phase/total amplitude ratio). Only sporadically discharging neurons (basal firing rate, <0.1 spikes/s) were influenced by 7-NI, which caused a statistically significant increase in their firing rate. In contrast, …
Involvement of nitric oxide-soluble guanylyl cyclase pathway in the control of maximal dentate gyrus activation in the rat.
2006
Summary Nitric oxide=soluble Guanylyl cyclase (NO=sGC) pathway on the maximal dentate gyrus activation (MDA) was studied in rats. The cerebral NO levels were modified by administrating 7-Nitroindazole (7-NI), a selective inhibitor of neuronal NOS, and L-arginine, a precursor of the synthesis of NO. 1H-[1,2,4]Oxadiazole[4,3-a]quinoxalin-1-one (ODQ), a specific inhibitor of the NO-sGC pathway, was administered to study the involvement of cGMP pathway. The epileptic activity of the dentate gyrus was obtained through the repetitive stimulation of the angular bundle; MDA parameters studied were: onset time, MDA duration and post-stimulus afterdischarge (AD) duration. 7-NI caused an increase of M…
Nitric oxide-sensitive guanylyl cyclase inhibits acetylcholine release and excitatory motor transmission in the guinea-pig ileum
1997
Abstract This study examined the mechanism through which nitric oxide inhibits the release of acetylcholine and excitatory motor neurotransmission in the guinea-pig ileum. The selective inhibitor of nitric oxide-sensitive guanylyl cyclase, 1 H -[1,2,4]oxadiazolo[4,3- a ]quinoxalin-1-one (ODQ), concentration-dependently enhanced both basal release (−log EC 50 : 6.8) and electrically (10 Hz) -evoked release (−log EC 50 : 6.0) of [ 3 H]acetylcholine from longitudinal muscle-myenteric plexus preparations preincubated with [ 3 H]choline. The increase by ODQ of basal release appeared to be exocytotic since it was prevented by tetrodotoxin (300 nM) and absence of calcium from the superfusion mediu…
Differential effects of isoliquiritigenin and YC-1 in rat aortic smooth muscle.
1997
We investigated the effects of isoliquiritigenin and YC-1 (3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole) on tension in endothelial-free rat aortic rings precontracted with phenylephrine (3 microM). Both compounds induced a concentration-dependent relaxation (EC50 of YC-1 1.9 microM and of isoliquiritigenin 9.4 microM). The effects developed faster with YC-1 than with isoliquiritigenin, and the effects of YC-1 were potentiated by isoliquiritigenin (10 microM). 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (30 microM) inhibited the effect of YC-1, but not of isoliquiritigenin. These results suggest that the effects of YC-1 are due to stimulation of soluble guanylyl cyclase activity, whereas …
Hepatic steatosis is not due to impaired fatty acid oxidation capacities in C57BL/6J mice fed the conjugated trans-10,cis-12-isomer of linoleic acid.
2004
Decreased body fat mass and liver steatosis have been reported in mice fed diets containing the conjugated linoleic acid trans-10,cis-12-C18:2 (CLA2), but not in those fed diets containing cis-9,trans-11-C18:2 (CLA1). Because the decrease in fatty acid (FA) oxidation may cause fat accumulation, we questioned whether the effects of both CLAs on enzyme activities and mRNA expression were related to liver FA oxidation. To address this question, 7-wk-old male C57BL/6J mice were fed for 4 wk a diet supplemented with 1% CLA1, CLA2, or cis-9-C18:1 (control) esterified as triacylglycerols. In CLA2-fed mice, the proportions of CLA2 in the total FA of liver lipids were substantially lower than those …
Minimal Change Esophagitis: Prospective Comparison of Endoscopic and Histological Markers between Patients with Non-Erosive Reflux Disease and Normal…
2004
<i>Introduction:</i> More than half the patients with gastroesophageal reflux disease (GERD) show no endoscopic abnormality or minimal change esophagitis (non-erosive reflux disease, NERD). We investigated the value of endoscopic and histological markers for the prediction of NERD before and after treatment with 20 mg esomeprazole. <i>Methods:</i> Between July and October 2002, consecutive patients presenting for upper endoscopy were stratified into GERD and non-reflux patients (control group) with the help of a questionnaire. The endoscopist was blind to the presence of reflux symptoms. Using magnifying endoscopes minimal change esophagitis was defined by the presen…