Effect Of Amytal Research Articles

Role of oxidative metabolism on endothelium-dependent vascular relaxation of isolated vessels.

The obligatory role of endothelium in mediating vasodilator response to numerous humoral agents has been definitely accepted. However, the chemical identity of endothelium-derived relaxing factor(s) (EDRF) and the mechanisms underlying its synthesis and release remain unclear. Much evidence suggests a compartmentalization of ATP into cells, such that ATP derived from glycolysis or from oxidative metabolism is used for different cellular functions. To investigate which energy source (i.e. oxidative v glycolytic metabolism) is preferentially used for the biosynthesis and/or release of EDRF, rings of rabbit thoracic aorta were studied in organ chambers. After preconstriction with PGF2 alpha, inhibition of glycolysis with either iodoacetate (300 microM) (n = 6) or 2-deoxyglucose (20 mM) (n = 6) did not affect concentration-response curve to the endothelium-dependent agent acetylcholine. In contrast, inhibition of oxidative metabolism with either 1 mM amytal or 5 microM rotenone markedly impaired relaxation to acetylcholine. In fact, maximal relaxation was 75 +/- 5% in control rings (n = 6), and 42 +/- 7% (P < 0.01) in amytal-treated rings (n = 6), whereas rotenone converted acetylcholine relaxation into constriction (n = 6; P < 0.001). The effect of amytal on endothelium-dependent relaxation was reversible, suggesting that endothelial cells were not damaged by the inhibitor. Amytal also markedly reduced endothelium-mediated relaxation to ADP (37 +/- 6%; P < 0.05; n = 5), as well as to the calcium ionophore A23187. Neither mitochondrial inhibitor affected relaxation to nitroglycerin, an endothelium-independent agent. Finally, amytal did not affect relaxation to S-nitrosocysteine (a recently proposed EDRF) (n = 5), suggesting that the effects on acetylcholine and ADP responses were not due to non-specific interferences with EDRF once released from endothelial cells. In conclusion, our data demonstrate that the active process of biosynthesis and/or release of EDRF requires energy derived mainly from mitochondrial oxidative metabolism.

Short-term and long-term memory deficit following intracarotid Amytal injection: Further support for the memory consolidation hypothesis

To test the three main hypotheses of the human amnesic syndrome (encoding, consolidation, retrieval), we designed an original protocol for memory assessment under Amytal that included, in addition to a retrograde memory measure, both short-term and long-term anterograde memory measures. Twenty epileptic patients with SEEG-confirmed unilateral temporal lobe foci were given right and left injections on successive days. Only the long-term memory measure for material presented under Amytal was significantly related to the presence of a temporal contralateral epileptogenic focus, even if it was assessed when the hemisphere had completely recovered from the effect of Amytal. Short-term memory deficits were observed equally often after injections ipsilateral and contralateral to the epileptogenic focus, and no retrograde amnesia was observed. These results are consistent with the consolidation hypothesis.

Effect of amytal on the permeability of the mitochondrial membrane in rat liver mitochondria

The effect of 5-ethyl, 5-isoamyl barbituric acid (amytal) on the permeability of the mitochondrial membrane has been investigated using rat liver mitochondria. It was found that amytal inhibits the malonate-malonate exchange, mediated by the dicarboxylate carrier, in a purely non-competitive manner. Furthermore, amytal causes release of intramitochondrial Pi from the matrix in the presence of N-ethylmaleimide. Some features of the Pi efflux induced by amytal in rat liver mitochondria have been studied. The efflux shows saturation characteristics, pH and temperature dependence according to a carrier-mediated process. It is suggested that the dicarboxylate carrier caused the efflux of Pi induced by amytal. The existence of subunits in the molecule of the dicarboxylate carrier is tentatively proposed.

Block of acid secretion by amytal and its partial reversal by menadione with ascorbate in the gastric mucosa of the guinea-pig

The effect of amytal on energy metabolism and acid secretion in an isolated gastric mucosa of the guinea-pig were studied. Determination of adenine nucleotides, creatine phosphate, pyruvate and lactate in the gastric mucosa showed that amytal depressed the levels of ATP, creatine phosphate and energy charge with elevation of the AMP and pyruvate levels. This treatment inhibited concomitantly acid secretion and active chloride transport detected by short circuit current. The addition of menadione with ascorbate to the medium in the presence of amytal partially restored ATP and energy charge levels and also induced a partial recovery of acid secretion and active chloride transport. These results suggest that ATP is a direct energy donor for acid secretion in the gastric mucosa of the guinea-pig.

Effect of Amytal on metabolism of perfused rat heart: relationship between glycolysis and oxidative phosphorylation

In perfused rat hearts, infusion of increasing concentration of Amytal caused progressive inhibition of respiration and increase in glycolytic activity. At maximal inhibition of respiration, with glucose as the substrate, glycolysis provided about 60% of the total ATP produced. The myocardial content of ATP remained constant irrespective of the infused Amytal concentration but [CrP]/[Cr] and [ATP]/[ADP]f[Pi] progressively decreased. Changes in the concentrations of glycolytic intermediates were observed, the most pronounced of which were increases in fructose 1,6-diphosphate and lactate contents and a decrease in the pyruvate level. Myocardial levels of oxaloacetate, malate, and alanine were elevated and so was alanine release from the tissue. Substitution of glucose with pyruvate caused a large increase in the concentrations of the tricarboxylic acid cycle intermediates and consequent accumulation of reducing equivalents in the mitochrondria. With the latter substrate, in the presence of Amytal, the rates of mitochondrial ATP production were higher than those with glucose as the substrate. The metabolic picture of the Amytal block resembles biochemical manifestations of human myopathies of mitochondrial origin, and therefore Amytal inhibition is a convenient model system for exploration of intermediary metabolism in these defects.

Redox involvement in acid secretion in the amphibian gastric mucosa

Gastric fundic metabolism was studied by spectroscopic observation in frog mucosa during transitions of secretory status in vitro and by direct measurement of pyridine nucleotides and associated metabolites in biopsies of dog fundic mucosa also during secretory oxidation of the redox components from flavin adenine dinucleotide (FAD) to cytochromea3. Addition of histamine resulted in reduction of these components with onset of secretion by about 50%. In contrast, the effect of apparently, burimamide and subsequently histamine on the ratio of nicotinamide adenine dinucleotide to nicotinamide adenine dinucleotide, reduced (NAD+/NADH) was relatively slight. Further, the presence of burimamide substantially reduces the effect of amytal on the pyridine nucleotide spectrum and abolishes the effect of amytal on FAD and the cytochromes. Measurements of lactate, pyruvate, α-ketoglutarate, NH3 and glutamate in the dog showed that whereas the calculated NAD+/NADH ratio in the cytoplasm declined with onset of secretion, the calculated mitochondrial ratio rose. No change was noted in the nicotinamide adenine dinucleotide phosphate/nicotinamide adenine dinucleotide phosphate, reduced (NADP+/NADPH) ratio. It is concluded that (1) H2 antagonists act by blocking substrate flow into the mitochondrial respiratory chain, (2) conversely, histamine stimulation acts at the level of substrate mobilization, and (3) there may be a cross-over in the mitochondrial chain between NAD+ and FAD.

The effect of amytal on hormone-sensitive lipase activation in adipose tissue in vitro

The effect of amytal on hormone-sensitive lipase activation in adipose tissue in vitro

Effect of amytal, pyridine nucleotides, and oxaloacetate on the respiratory inhibition-activation cycles in mitochondria

Rat liver mitochondria which were not able to show spontaneous oscillations of the respiratory intensity responded in the usual cyclic manner after addition of low concentrations of oxaloacetate. Amytal added to mitochondrial systems in which oxygen uptake had been inhibited, abruptly increased the respiratory rate. After a short period of active respiration, a gradual decline of oxygen utilization ensued. With amytal added from zero time respiration occurred at a high rate for a longer time than in its absence, the same steady decline being noted afterwards. In the presence of NAD the first inhibition of the respiration began earlier than in its absence or when NADH 2 was added instead of NAD. The subsequent pattern of oxygen uptake, both in the presence of NAD as of NADH 2, presented less fluctuation. In the absence of ATP no oscillations of respiration but a gradual decline down to low values was obtained. One m M NAD or 1 m M NADH 2, when present from zero time, re-established the cyclic course of respiration. One half to 2 m M ATP, added after the onset of inhibition, caused a marked increase in the rate of oxygen uptake. Amytal was less effective in stimulating oxygen uptake in these systems than was ATP.

Studies on the relation of the adenosinetriphosphate-inorganic phosphate exchange reaction of mitochondria to oxidative phosphorylation

The effects of a number of various agents on the inorganic phosphate-adenosinetriphosphate exchange (P i-ATP exchange) reaction catalyzed by rat-liver mitochondria have been studied. The types of agents included certain dyes, various respiratory inhibitors, and a number of other compounds of known interest in studies of oxidative phosphorylation. Oxidized, but not reduced, 2,6-dichlorophenolindophenol completely inhibited P i-ATP exchange and oxidative phosphorylation and partially depressed respiration supported by various substrates. The effect on the respiration was not eliminated by 2,4-dinitrophenol. Reduction of the dye after previous treatment of the mitochondria with the oxidized form partially restored the P i-ATP exchange. Methylene blue acted in all respects similarly to 2,6-dichlorophenolindophenol, while ferricyanide and a number of other one-electron acceptors were without inhibitory effects. Cyanide and antimycin A inhibited P i-ATP exchange to a maximal extent of 20–40%, whereas amytal gave an inhibition which was progressive with increasing concentration and could approach completeness. The progressive character of the amytal inhibition was not eliminated by the presence of antimycin A. The effect of amytal, in contrast to those of cyanide and antimycin A, was partially prevented by succinate; antimycin A, but not cyanide, abolished the succinate effect. The effects of adenosinemono- and diphosphate, p-chloromercuribenzoate, azide, fluoride, arsenate, ethylenediaminetetraacetate, deoxycholate and 2,4-dinitrophenol on P i-ATP exchange were investigated and compared with those on oxidative phosphorylation and/or mitochondrial adenosinetriphosphatase reactions. A short exposure of mitochondria to 2,4-dinitrophenol at 2°C resulted in a depression of the P i-ATP exchange with a maintenance of the net phosphate uptake upon the addition of substrate. On the basis of the data obtained it is concluded that the P i-ATP exchange reaction does not reflect all three phosphorylations occurring along the respiratory chain in a random manner, but is related mainly to one of these: that occurring at the diaphorase level. The implications of these conclusions for the mechanisms of respiratory chain phosphorylations and of dinitrophenol-activated adenosinetriphosphatase is discussed.

The effect of amytal on the cardiac output and peripheral resistance of man.

Measurements of cardiac output and intra-arterial pressure on 5 normal young men and 5 hypertensive patients before and during sedation with Amytal demonstrated a decreased cardiac output and an increased peripheral resistance during the period of sedation. It is concluded that the theoretic basis for the use of Amytal sedation as a device for selection of hypertensive patients for sympathectomy is not valid.

PSYCHOLOGICAL CHANGES IN NORMAL AND ABNORMAL INDIVIDUALS UNDER THE INFLUENCE OF SODIUM AMYTAL

Back to table of contents Previous article Next article ARTICLENo AccessPSYCHOLOGICAL CHANGES IN NORMAL AND ABNORMAL INDIVIDUALS UNDER THE INFLUENCE OF SODIUM AMYTALErich LindemannErich LindemannSearch for more papers by this authorPublished Online:1 Apr 2006https://doi.org/10.1176/ajp.88.6.1083AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail PDFThis content is only available as a PDF. Access content To read the fulltext, please use one of the options below to sign in or purchase access. Personal login Institutional Login Sign in via OpenAthens Purchase Save for later Item saved, go to cart PPV Articles - American Journal of Psychiatry $35.00 Add to cart PPV Articles - American Journal of Psychiatry Checkout Please login/register if you wish to pair your device and check access availability. Not a subscriber? Subscribe Now / Learn More PsychiatryOnline subscription options offer access to the DSM-5 library, books, journals, CME, and patient resources. This all-in-one virtual library provides psychiatrists and mental health professionals with key resources for diagnosis, treatment, research, and professional development. Need more help? PsychiatryOnline Customer Service may be reached by emailing [email protected] or by calling 800-368-5777 (in the U.S.) or 703-907-7322 (outside the U.S.). FiguresReferencesCited byDetailsCited byTherapy of Catatonia in Schizophrenia and Schizophrenia Spectrum Disorders29 September 2022 | Psikhiatriya, Vol. 20, No. 3Twentieth Century, the First Half: The Pre-psychopharmacologic Era27 November 2021Integrating psychotherapy and psychopharmacology: psychedelic-assisted psychotherapy and other combined treatments1 June 2020 | Expert Review of Clinical Pharmacology, Vol. 13, No. 6History of Psychiatry, Vol. 30, No. 3Acta Psychiatrica Scandinavica, Vol. 136, No. 5History of Psychology, Vol. 7, No. 4British Journal of Psychiatry, Vol. 172, No. 4Psychosomatics, Vol. 38, No. 6Pain, Vol. 70, No. 1Acta Psychiatrica Scandinavica, Vol. 93, No. 2La narcose sous barbiturique: mutisme *1 November 1992 | The Canadian Journal of Psychiatry, Vol. 37, No. 9Psychological Medicine, Vol. 20, No. 4General Hospital Psychiatry, Vol. 10, No. 3Erich Lindemann as humanist, scientist, and change agent1 October 1984 | American Journal of Community Psychology, Vol. 12, No. 5General Hospital Psychiatry, Vol. 6, No. 3Overview: clinical applications of the Amytal interview in psychiatric emergency settings1 April 2006 | American Journal of Psychiatry, Vol. 139, No. 5Psychosomatics, Vol. 23, No. 4International Journal of Neuroscience, Vol. 17, No. 1International Journal of Neuroscience, Vol. 13, No. 4Annals of Emergency Medicine, Vol. 9, No. 10Journal of the American College of Emergency Physicians, Vol. 8, No. 7Psychosomatics, Vol. 19, No. 2Journal of Psychiatric Research, Vol. 4, No. 2British Journal of Psychiatry, Vol. 112, No. 488American Journal of Clinical Hypnosis, Vol. 6, No. 2Psychopharmacologia, Vol. 1, No. 1The Psychiatric Quarterly, Vol. 31, No. 1-4Journal of Neurology, Neurosurgery & Psychiatry, Vol. 19, No. 2Journal of Mental Science, Vol. 101, No. 424CHANGES IN SYMBOLIC EXPRESSION WITH AMYTAL SODIUMEDWIN A. WEINSTEIN, and SIDNEY MALITZ1 April 2006 | American Journal of Psychiatry, Vol. 111, No. 3Journal of Projective Techniques, Vol. 18, No. 2PSYCHOPATHOLOGY OF SCHIZOPHRENIA AND DEPRESSIONI. Effect of Amytal and Amphetamine Sulfate on Level and Maintenance of AttentionPAUL E. HUSTON, and RITA SENF1 April 2006 | American Journal of Psychiatry, Vol. 109, No. 2NARCOSYNTHESIS IMMEDIATELY FOLLOWING INSULIN SHOCKFive-Year Follow Up and Supplementary ReportSOL LEVY1 April 2006 | American Journal of Psychiatry, Vol. 108, No. 8A critique of intravenous barbiturate usage in psychiatric practiceThe Psychiatric Quarterly, Vol. 22, No. 1-4The Psychiatric Quarterly, Vol. 22, No. 1-4The Psychiatric Quarterly, Vol. 18, No. 3The Psychiatric Quarterly, Vol. 15, No. 1Journal of Mental Science, Vol. 85, No. 356The Psychiatric Quarterly, Vol. 12, No. 4 Volume 88Issue 6 May 1932Pages 1083-1091 Metrics PDF download History Published online 1 April 2006 Published in print 1 May 1932

Glycogen Formation under Amytal Anaesthesia.

In a previous report1 it was pointed out that dogs under amytal anesthesia exhibited a decreased capacity to assimilate injected glucose. Preliminary to a study of factors influencing the distribution of injected glucose, it was desirable to know whether this effect of amytal was a quantitative one affecting all tissues or whether its effect was limited primarily to certain tissues.A comparison of glycogen formation in the unanesthetized and anesthetized (amytal) animal has been made in experiments on 8 dogs. Samples of liver and muscle tissue frog glycogen determinations were quickly removed under light ethylene anesthesia. One hour later glucose was injected at the rate of 3 gm. per kilo of body weight per hour for a period of 3 hours. One hour later when the blood sugar had returned to approximately its original value, samples of tissue were removed from the opposite side for analysis.It was found that approximately the same increase in muscle glycogen had occurred in animals with or without amytal ane...