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Biomedical subjects

J D Sinclair

Publications and source records attributed to J D Sinclair.

15 recordsLinked to original sources
PubMed1992

Localization of the primary sites of genetic influence.

When studying the nervous system of animal lines developed for specific genetically-determined behavioral differences, how does one tell whether a difference between the lines found at one specific location was caused by a direct genetic interaction at that location or by an interaction at some distant site which was then imposed on the tested location? The form of the line difference can help to answer this question. One particular form, called an inverse line difference, is shown to have a higher probability of being close to the location of the direct gentic interaction.

Alcohol Drinking↗
PubMed1992

Alcohol elimination and the regulation of alcohol consumption in AA and ANA rats.

Previous studies have usually found that animals with either higher alcohol elimination rates or ADH (alcohol dehydrogenase, EC1.I.I.I) activities have higher voluntary intakes of alcohol than ones with lower elimination rates. This relationship has now been studied in the AA and ANA rat lines genetically developed, respectively, for high and low alcohol consumption. Female AA and ANA rats had their alcohol elimination rate measured before being given a free choice between 10% (v/v) alcohol and water for 3 weeks. The elimination rate was then measured again and liver ADH activity was determined. The alcohol elimination rate was significantly higher in AA than ANA rats before drinking and was increased by alcohol drinking in AA but not ANA rats. ADH activity was similar in both lines and unrelated to either alcohol drinking or elimination rates, suggesting that the enzyme activity is not a rate-limiting factor in the alcohol metabolism of these two lines. The present results support the conclusion that alcohol elimination and alcohol consumption are partially determined by genetics. Furthermore, although alcohol elimination itself probably does not have direct control over drinking, some factor related to the alcohol elimination rate appears to be among the mechanisms influencing the level of alcohol drinking.

Alcohol Dehydrogenase↗
PubMed1979

Alcohol-deprivation effect in rats genetically selected for their ethanol preference.

Alcohol deprivation and alternate-day access increase voluntary alcohol drinking by normal rat strains in a consistent manner. In contrast, the ANA strain developed by selective outbreeding for low alcohol intake during continuous access showed no increase in their alcohol drinking during alternate-day access and only a small increase after a week of deprivation. The AA strain developed for high alcohol intake showed an increase after a week of deprivation similar in magnitude to that of normal rats but persisting much longer. In order to have been selected, these deviant reactions to deprivation must have been related to deviant baseline levels of alcohol drinking during continuous access, but presently even the AAs with the lowest baselines show the persistent increase and the ANAs with the highest baselines show only small increases. Strain differences were also found in spontaneous alternation in a T-maze. A modification of Pinel and Huang's inhibitory factor model accounting for these results is presented.

Alcohol Drinking↗
PubMed1978

Passing remarks.

Explore the source record for details and available documents.

Cardiac Catheterization↗
PubMed1976

Thoracic and arterial pressures, blood flow and syncope.

The relationship between elevation of the thoracic pressure and the thoracic volume and blood pressure was investigated in man. Raising the thoracic pressure produced an increasing hypotension and ultimately fainting. Cine-radiography showed a reduction in heart size while the high thoracic pressure was maintained.

Animals↗
PubMed1976

Motivation for alcohol in rats: position and bottle preferences do not cause drinking.

Position preference, i.e., the tendency to drink from onelocation rather than the other, was found to be relatively unimportant in determining the drinking behavior of rats presented with a choice between water and a 7% (v/v) ethanol solution in typical two-bottle choice situations. It accounted for essentially none of the variance in rats generally drinking more alcohol solution than water after prolonged previous alcohol experience, and in rats consuming very little alcohol; only in rats drinking slightly less alcohol solution than water was it found to have an influence. Similarly, bottle preference, i.e., the tendency to drink from one of the two bottles regardless of its position or contents, andposition preference were found to have almost no effect on heavy-drinking rats even on their first day of exposure and on low-drinking rats after about three days of access to alcohol.

Alcohol Drinking↗
PubMedDate not supplied

The limited access paradigm: description of one method.

Restricting access to alcohol to a short period daily causes rats, in effect, to drink on command. They usually begin drinking alcohol immediately when it is first made available each day and consume a rather constant amount during each access period. The procedure thus has a variety of useful applications. The specific method reported here in detail provides continual access to food and water, but access to unflavored 10% ethanol solution only 1 h/d, all in the home cage, and produces mean alcohol intakes from 0.5-1.0 g/kg in the access hour.

Alcohol Drinking↗
PubMedDate not supplied

Human cardiorespiratory responses to acute cold exposure.

1. Respiratory and circulatory functions of minimally clad human subjects were studied before and during acute exposure to ambient temperatures of 4.5-6.5 degrees C. 2. After 1 h of cold exposure, subjects showed increases of ventilation, O2 UPTAKE AND CARDIAC OUTPUT. Rectal temperatures fell. 3. During exercise in the cold conditions, oxygen uptake and cardiac output were greater than during the same exercise at normal temperature. 4. The increased cardiac output during cold exposure was achieved by an increase of stroke volume rather than heart rate; this finding is in contrast to changes during bicycle exercise and isometric exercise at normal ambient temperatures. 5. We conclude that the cardiorespiratory effects of cold exposure are not superseded by the response to moderate exercise. The difference between heart rate and stroke volume at increased levels of cardiac output during exercise at normal temperatures and during rest and exercise in cold conditions may be explained by changes of arterial baroreceptor input and of blood catecholamine levels.

Adolescent↗