Determination of hepatic acetaldehyde and its biphasic relationship to the ethanol concentration in rats.

In situ freeze clamping of livers using either pentobarbital anaesthesia (40 mg/kg) or cervical dislocation as means of sacrificing rats were compared in regard to the determination of the hepatic acetaldehyde (AcH) concentration following ethanol exposure. It was demonstrated that following cervical dislocation, the AcH concentration decreased by 50%, ethanol decreased by 7%, and the mitochondrial redox state, expressed by the 3-hydroxybutyrate/acetoacetate ratio, increased by 100% within 40 s. The extrapolated 0-time values for AcH, ethanol concentration, and 3-hydroxybutyrate/acetoacetate ratio were equal to values obtained from pentobarbital anaesthetized rats.

Difficulties in measuring human blood acetaldehyde concentrations during ethanol intoxication.

The determination of human blood acetaldehyde (AcH) concentrations is complicated by two artefactual reactions, one resulting in the disappearance of AcH prior to deproteinization of the blood and the other resulting in the formation of AcH during deproteinization. The AcH formation increases with increasing ethanol concentration and decreases with increasing blood dilution, while the rapid AcH disappearance is initiated at the start of the blood collection. The magnitudes of these artefactual reactions are of such an order that a re-evaluation of previous reports on human blood AcH levels is needed.

Evidence against a biphasic effect of acetaldehyde on voluntary ethanol consumption in rats.

A group of 27 male Long-Evans rats was given a 2 week period of free-choice ethanol and consumed 1.26 +/- 1.27 g/kg/day (mean +/- SD).

Lack of difference in blood acetaldehyde of alcoholics and controls after ethanol ingestion.

Ethanol and acetaldehyde (AcH) metabolism were studied in male Caucasian alcoholic subjects and matched controls following 1 g/kg ethanol, which was administered after a 10 day, ethanol-free period. The rate of ethanol elimination was higher (p greater than 0.05) in the alcoholics (0.

The aversive effect of acetaldehyde on alcohol drinking behavior in the rat.

There are a number of indications suggesting that acetaldehyde (AcH) is one factor affecting the alcohol drinking behavior in laboratory animals. In the present study, the voluntary alcohol consumption in a free-choice situation was recorded in 17 females Sprague-Dawley rats fed with two different diets. The first diet (commercial Astra-Ewos, Sweden) caused significantly (p less than 0.

Problems and pitfalls in acetaldehyde determinations.

The determination of acetaldehyde in biologic samples is complicated by a variety of formation and disappearance reactions occurring in the present methods of acetaldehyde analyses. The acetaldehyde formation (ethanol oxidation) in deproteinized supernatant of tissue preparations is prevented by the use of thiourea. During deproteinization, however, it is not inhibited by thiourea, and this remains the main problem in blood acetaldehyde determinations.

Bone mineral and surface charge.

A triple association has been observed between a high negative surface charge, bone morphogenetic activity, and in vitro recalcificaiton in implants of demineralized bone matrix. Proplast fills with bony tissue when implanted in the body and shows the same triple association. The higher the negative surface charge, the greater is the mass of new bone induced and the higher degree of mineralization when placed in a calcifying solution in vitro.

Preliminary clinical evaluation of the effect of small electrical currents on the healing of jaw fractures.

A clinical investigation has been carried out into the effect of small electrical currents on the healing of mandibular fractures. Electrical stimulation of fracture healing was carried out in 40 patients with a direct current of 10 or 20 microamperes delivered through a platinum electrode. An equal number of patients with similar fractures were selected as controls.

Affinity chromatography of lipoxygenases.

A number of aminohexyl agarose derivatives of unsaturated fatty acids have been prepared and evaluated as materials for the affinity chromatography of soybean and pea lipoxygenases. A practical method for a one-stage purification of soybean lipoxygenase-1, with a purification factor of 16, is described, using either linolenate or docosa-4,7,10,13,16,19-hexaenoate as ligands. Results show that alleged competitive inhibitors do not cause sharp elution from the affinity column, and that there is an increasing specificity of binding and sharpness of elution as the proportion of unsaturation in the ligand is increased.

Regulation of acetaldehyde metabolism during ethanol oxidation in perfused rat liver.

Acetaldehyde (AcH) metabolism during ethanol oxidation has been studied in once-through perfused rat livers. The interest was focused upon the interrelations between the hepatic AcH concentration, AcH oxidation rate, ethanol metabolism, cytosolic and mitochondrial redox state, and aldehyde dehydrogenase (ALDH) activity. Correlational analyses between the possible regulative factors and regulated parameters were made and the following main conclusions drawn.

Acetaldehyde metabolism in vivo during ethanol oxidation.

The liver is the primary site for the oxidation of ethanol-derived acetaldehyde (AcH) in the rat. Only a small amount of the total AcH formed in this organ escapes into the rest of the body, but this amount increases with increasing hepatic ethanol concentrations. The bulk of the hepatic AcH output is eliminated extrahepatically, thus drastically changing the AcH level from that initially leaving the liver.

The prevention of hypertension.

Our way to prevention is to find a list of traits known to be predictors of elevated blood pressure. This list of predictors offers means for the early identification of susceptibile persons. Years of experience in preventive work indicate that such identification is always useful for developing preventive programmes, since it gives a focus for action (5).

Bone morphogenesis and surface charge.

The electrophoretic mobility of variously treated bone specimens, with and without bone morphogenetic activity, has been measured in physiological solutions. The Bone Morphogenetic Principle appears to be associated with a minimum negative surface charge on the implant that corresponds to that of normal undemineralized cortical bone in saline. Demineralization of cortical bone in 0.

Effects of fructose and glucose on ethanol-induced metabolic changes and on the intensity of alcohol intoxication and hangover.

The effects of fructose and glucose on the metabolic changes induced by ethanol and on the intensity of alcohol intoxication and hangover were studied in 109 healthy male volunteers. After 10 hours of fasting, the subjects were given 1.75 g of ethanol per kg body wt during 3 hours under controlled laboratory conditions.

Role of cytosolic rat liver aldehyde dehydrogenase in the oxidation of acetaldehyde during ethanol metabolism in vivo.

The activity of a high-Km aldehyde dehydrogenase in the liver cytosol was increased by phenobarbital induction. No corresponding increase in the oxidation rate of acetaldehyde in vivo was found, and it is concluded that cytosolic aldehyde dehydrogenase plays only a minor role in the oxidation of acetaldehyde during ethanol metabolism.