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Biomedical subjects

J A Grinker

Publications and source records attributed to J A Grinker.

25 records · Page 2Linked to original sources
PubMed1980

Effects of d-amphetamine and fenfluramine on feeding pattens and activity of obese and lean Zucker rats.

The effects of two doses of d-amphetamine and fenfluramine on male Zucker rats maintained ad lib on solid and liquid diets were investigated using the technique of meal pattern analysis. Amphetamine-induced anorexia was of short duration in both obese and lean rats. In the lean rats, anorexia was followed by rebound feeding resulting in little or no reduction in total daily intake. The drug reduced meal sizes of obese but not lean rats and caused a transient decrease in meal frequency. Increased spontaneous activity paralleled the decreased food intake. In contrast, anorexia following fenfluramine was greater, more prolonged and of equivalent magnitude in obese and in lean rats. No rebound feeding was observed. Reduction in intake was achieved primarily by changes in meal size rather than in meal frequency. These data demonstrate that food intakes of genetically obese Zucker rats are more susceptible to the action of d-amphetamine than those of lean rats, and are consistent with reports of differential neurotransmitter levels in the obese and lean rats.

Animals↗
PubMed1978

Food and water intake, meal patterns and activity of obese and lean Zucker rats following chronic and acute treatment with delta9-tetrahydrocannabinol.

A series of experiments investigated the effects of delta9-THC on food and water intakes and wheel-running activity of Zucker rats. Following chronic drug treatment (15 days), food and water intakes of all rats were suppressed, but intakes and body weights of the obese rats recovered more slowly than those of lean rats. Acute effects of the drug (24 hr) were examined using techniques of meal pattern analysis and were discussed in relation to known patterns of anorectic drug action. The drug-induced anorexia was both delayed and of short duration, with no rebound eating observed for either solid or liquid diets. Both feeding rate and meal size were reduced, but meal frequency was transiently increased. The time of onset of the first meal remained unchanged. The time course of the suppression of feeding was paralleled by a suppression in running-wheel activity. These findings suggest that the drug-induced reduction in food and water intake may be the result of a decreased level of arousal.

Animals↗
PubMedDate not supplied

Sensory responses, dietary-induced obesity and biochemical values in Sprague-Dawley rats.

Food intake and body weight gain variability in Sprague-Dawley (SD) rats exposed to a palatable high-fat diet were examined in relation to sensory responses and biochemical parameters in two experiments. In the first experiment, varying sucrose concentrations (4-32% wt./vol.) were randomly presented for 20 minutes to ad lib chow-fed rats. Each rat's sensory response was expressed as Beta (B), or the slope of the regression between solute intake and concentration, and used to assign rats to diet groups. In the second experiment, responsiveness to fat emulsions (1-37%) were similarly measured and categorized. In both experiments sensory responses to sucrose were significantly related to weight gain/fatness on the high-fat diet (lab chow-corn oil). Sensory responsiveness to the fat emulsions was unrelated to sucrose responsiveness or to high-fat feeding. Biochemical parameters (insulin, cholesterol, triglycerides, lipoproteins) reflected increased caloric (fat) intake, as well as sucrose responsiveness. Predictors (sensory responses, biochemical values) of response to chronic (4 months) or short-term (less than 2 months) high-fat diets are discussed.

Adipose Tissue↗
PubMedDate not supplied

Body composition, body size estimation, and attitudes towards eating in male college athletes.

A number of different parameters relating to eating history and body composition were examined in male college athletes during the course of an athletic season. Wrestlers, who often lose weight to meet the requirements of the sport, were compared with other athletes (swimmers, nordic skiers) who typically maintain weight during vigorous training. By the end of the athletic season, the wrestlers had reduced body weights and reported a reduction in caloric intakes. Wrestlers scored higher than swimmers and nordic skiers on scales measuring dietary restraint and attitudes towards eating (EAT). The groups differed primarily on items dealing with fluctuations in body weight and with dieting behaviors. There were no significant differences between groups on the estimates of body size and no effect of seasonal training. However, a small subsample of the wrestlers who scored high on the restraint and EAT scales also showed distortions in estimates of body size. Wrestlers may represent a population at risk for the newly reported sports-induced disturbances in eating.

Adolescent↗