The neural mechanisms through which the state of anesthesia arises and dissipates remain unknown. One common belief is that emergence from inverse process induction, brought about by elimination anesthetic drugs their CNS site(s) action. Anesthetic-induced unconsciousness may result specific interactions anesthetics with circuits regulating sleep wakefulness. Orexinergic agonists antagonists have potential to alter stability anesthetized state. In this report, we refine role endogenous...

The current study examined the effects of bosentan, an orally active antagonist endothelin-A and -B receptors, on development maintenance hypoxia (10% O2)-induced pulmonary hypertension vascular remodeling in rat. Pretreatment with bosentan (100 mg.kg-1.day-1, 1 gavage/day for 2 days) completely blocked vasoconstrictor response to acute hypoxia. Chronic treatment mg.kg-1.day-1 po food) instituted 48 h before hypoxic exposure prevented subsequent hypertension, attenuated associated right...

To test the hypothesis that endothelin (ET)-1 synthesis and ET receptor levels are increased selectively in lung of rats with chronic hypoxic pulmonary hypertension, current study examined effects exposure to hypoxia (10% O2, 1 atm, 4 wk) on arterial pressure, ET-1 plasma lung, ETA ETB mRNA heart, artery, aorta, kidney, spleen, liver. Hypoxic was associated increases levels, stores lung. In thoracic aorta four heart chambers, were increased, but unchanged from air control levels. No change...

The current study examined the contributions of angiotensin-converting enzyme (ACE) vs. chymase to angiotensin II (ANG II) generation in membrane preparations from left ventricles humans, dogs, rabbits, and rats total heart mice. ACE activity were measured extracted with low or high detergent (LD HD, respectively) concentrations. We hypothesized that ACE, which is bound vivo, would be preferentially localized HD preparation, whereas chymase, cytoplasm cardiac interstitium, LD preparation. In...

One major unanswered question in neuroscience is how the brain transitions between conscious and unconscious states. General anesthetics offer a controllable means to study these transitions. Induction of anesthesia commonly attributed drug-induced global modulation neuronal function, while emergence from has been thought occur passively, paralleling elimination anesthetic its sites central nervous system (CNS). If this were true, then CNS concentrations on induction would be...

The selective endothelin-A (ETA)-receptor antagonist BQ-123 has been shown to prevent chronic hypoxia-induced pulmonary hypertension in the rat. Therefore current study we utilized test hypothesis that blockade of ETA receptor can reverse as well increase mean artery pressure, right ventricle-to-left ventricle plus septum ratio, and percent wall thickness small (50-100 microns) arteries observed male Sprague-Dawley rats exposed normobaric hypoxia (10% O2, 2 wk). Infusion (0.4 mg.0.5...

Exposure to hypoxia is associated with increased pulmonary artery pressure and plasma endothelin-1(ET-1) levels selective enhancement in ET-1 peptide mRNA endothelin-A (ETA) receptor rat lung. The current study tested the hypothesis that endogenous can account for hypoxia-induced hypertension via a paracrine effect on ETA receptors Intravenous infusion of antagonist BQ-123 (D-Trp-D-Asp-Pro-D-Val-Leu) (0.4 mg/microliters at 1 microliter/h) into Sprague-Dawley rats beginning 4 h before 90 min...

Exposure to hypoxia is associated with increased pulmonary artery pressure and plasma endothelin (ET-1) levels selective enhancement of ET-1 peptide messenger RNA (mRNA) endothelin-A (ET-A) receptor mRNA in rat lung. Our study tested the hypothesis that A-127722, an orally active antagonist ET-A receptor, can prevent hypoxia-induced hypertension vascular remodeling rat. Pretreatment A-127722 (3, 10, 30 mg/kg/day drinking water for 2 days) caused dose-dependent inhibition vasoconstrictor...

We tested the hypothesis that angiotensin-converting enzyme (ACE) inhibitor therapy prevents volume-overload hypertrophy in dogs with chronic mitral regurgitation (MR). Seven adult mongrel receiving ramipril (R; 10 mg orally, twice/day) for 4 mo were compared 11 no R (N) after induction of MR. Cine-magnetic resonance imaging demonstrated left ventricular (LV) mass increased R-MR [80 +/- (SE) to 108 7 g, P < 0.01] and N-MR (92 112 8 0.001). LV myocyte cell length was greater (203 6 177...

The current study was designed to test the hypothesis that intracardiac angiotensin-converting enzyme (ACE) activity, chymase-like and angiotensin (ANG) peptide levels are increased positively related wall stress estimates in response chronic low pressure volume overload of mitral regurgitation produced by percutaneous chordal rupture dog. Chronic (MR) resulted an increase left ventricular (LV) end-diastolic [59 +/- 11 (SD) 103 32 ml, P < 0.001], LV mass (96 17 114 23 g, 0.001), a...

Objective Our objective was to evaluate ethnic differences in response morphine and determine whether any detectable were pharmacokinetically based. Methods This cohort study carried out a teaching hospital. Sixty‐six young, healthy male subjects from 3 groups (Caucasians, native Indians, Latinos; n = 22 each group) consented participate. All received an intravenous bolus of 0.08 mg/kg followed by 0.002 · min infused for 30 minutes. Respiratory evaluated with the carbon dioxide rebreathing...

We utilized mice with homozygous disruption of angiotensin-converting enzyme (ACE) (−/−), heterozygous deletion ACE (+/−), and wild-type (+/+) to test the hypothesis that genetic variation in modulates tissue plasma angiotensin (ANG) II concentrations. With use ANG I as substrate, kidney, heart, lung activity was reduced 80% −/− compared +/+ mice. However, concentrations II-to-ANG ratios did not differ among genotypes. In contrast, were <2 fmol/ml, whereas extremely high (765 fmol/ml)....

Background —We have previously demonstrated that angiotensin II (Ang II) levels in the interstitial fluid (ISF) space of heart are higher than blood plasma and do not change after systemic infusion Ang I. In this study, we assess enzymatic mechanisms (chymase versus ACE) by which is generated ISF dog vivo. Methods Results —Cardiac microdialysis probes were implanted left ventricular (LV) myocardium (3 to 4 per dog) 12 anesthetized open-chest normal dogs. I measured at baseline during (15...

Abstract Adsorption of bovine serum albumin (BSA) and fibrinogen (Fg) was measured on six distinct bare dextran- hyaluronate-modified silicon surfaces created using two dextran grafting densities three hyaluronic acid (HA) sodium salts derived from human umbilical cord, rooster comb Streptococcus zooepidemicus. Film thickness surface morphology depended the HA molecular weight concentration. BSA coverage enhanced in competitive adsorption BSA:Fg mixtures. Dextranization differentially...

The sleep-promoting ventrolateral preoptic nucleus (VLPO) shares reciprocal inhibitory inputs with wake–active neuronal nuclei, including the locus ceruleus. Electrophysiologically, neurons in VLPO are directly depolarized by general anesthetic isoflurane and hyperpolarized norepinephrine, a wake-promoting neurotransmitter. However, integration of these competing influences on VLPO, sleep- anesthetic-active structure, has yet to be evaluated either brain slices vitro or intact organism....

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTESR studies of the thietane and thiirane radical cations in freon matrixes. Evidence for ethylene molecule extrusion from a .sigma.* dimer cation [C2H4S-SC2H4.bul.+]Xue Zhi Qin, Qing Cheng Meng, Ffrancon WilliamsCite this: J. Am. Chem. Soc. 1987, 109, 22, 6778–6788Publication Date (Print):October 1, 1987Publication History Published online1 May 2002Published inissue 1 October...

Abstract We studied cardiovascular phenotypes in wild-type (+/+), heterozygous (+/−), and homozygous mutant (−/−) mice for an insertional inactivation of the angiotensin-converting enzyme (ACE) gene ( Ace mice, ACE humans). Compared with +/+ baseline mean arterial pressure was not significantly altered +/− but reduced by 51±4 mm Hg −/− mice. Although pressor response to injected angiotensin II did differ three genotypic groups, I strongly affected genotype: group (+26% baseline), Ang close...

Cyanide toxicity is a complication of sodium nitroprusside administration. Cardiac surgery may increase the risk cyanide toxicity, because hemolysis during cardiopulmonary bypass (CPB) catalyze release free from nitroprusside.We obtained serial blood specimens 25 cardiac surgical patients CPB. Plasma were analyzed for hemoglobin concentration and ability to generate anion upon exposure nitroprusside.Hemolysis based on plasma-free increased over time CPB at an average rate 0.27 mg x dL(-1)...