Biomedical subjects

R L Hegstad

Publications and source records attributed to R L Hegstad.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Effects of weight gain and loss on metabolic rate, glucose tolerance, and serum lipids in domestic cats.

Weight gain is a common problem in domestic cats, but little is known about its metabolic effects. The purpose of this study was to determine the effects of diet-induced weight gain and subsequent weight loss on metabolic rate, body composition, and glucose tolerance. Gain of approximately 20 per cent body weight (divided approximately equally between fat and fat-free mass) over three months resulted in insulin resistance in females, indicated by increases in basal insulin concentration (68.2+/-7.9 to 119+/-16.5 pmol litre(-1), P<0.05), insulin peak response to glucose (241.1+/-31.6 to 315.0+/-23.0 pmol litre(-1), P<0.05), and deltaI/deltaG (14.2+/-2.6 to 18.1+/-1.3 pmol mmol(-1), P<0.05) compared with pre-gain values. The same numerical trend was noted in male cats, however, changes were not significant (P>0.05). Alterations in serum lipids included significant (P<0.05) elevations in triglyceride concentrations in male cats and decreased beta-lipoprotein concentrations in both genders. Weight loss over three months normalised basal insulin, insulin response to glucose, and serum triglyceride concentrations, and resulted in significant (P<0.05) decreases in serum concentrations of beta- and prebeta-lipoproteins, cholesterol, and triiodothyronine. Diet-induced weight gain of three months' duration, followed by three months' maintenance of increased body weight did not affect fasting or resting metabolic rate. Development and severity of impaired glucose tolerance, insulin resistance, and other changes may be affected by duration and possibly severity of weight gain.

Adipose Tissue↗

PubMedDate not supplied

Alterations in carbohydrate metabolism in canine lymphoma.

Following an overnight fast, blood samples were obtained from 14 dogs with previously untreated lymphoma before and 5, 15, 30, 45, 60, and 90 minutes following an intravenous challenge with 500 mg/kg dextrose. Samples were assayed for glucose, lactate, and insulin concentrations and compared statistically with ten control dogs of similar weight and age undergoing an identical dextrose challenge. Dogs with lymphoma had similar glucose tolerance curves when compared with controls. Lactate concentrations were significantly higher (P less than 0.001) at baseline and all time periods of the glucose tolerance test in dogs with lymphoma when compared with controls. Rise in lactate concentrations over baseline levels in the first 30 minutes of the glucose tolerance test were significantly higher in dogs with lymphoma (P = 0.011). Insulin concentrations were significantly higher (P less than 0.001) at baseline and at the 5-, 45-, 60-, and 90-minute time periods of the glucose tolerance test in dogs with lymphoma. Rise in insulin concentrations over baseline in the first 5 minutes of the glucose tolerance test were also significantly greater in dogs with lymphoma (P = 0.021). These results indicate carbohydrate metabolism is altered in dogs with lymphoma. Many of these alterations parallel those observed in human patients suffering from cancer cachexia making canine lymphoma a potential model for further study of the pathogenesis and therapy of cancer cachexia.

Animals↗

PubMedDate not supplied

Evaluation of the ICAGEN-Target canine ovulation timing diagnostic test in detecting canine plasma progesterone concentrations.

Accuracy of the ICAGEN-Targeta progesterone enzyme-linked immunosorbent assay (ELISA) test kit to measure plasma progesterone was compared to that of radioimmunoassay (RIA) in 166 canine samples. Overall agreement of ICAGEN-Target ELISA and RIA was 85% (141/166). Agreement of ELISA and RIA at high (5 ng/ml or greater), medium (greater than 1 ng/ml, less than 5 ng/ml), and low (0 to 1 ng/ml) plasma progesterone concentrations was 96% (72/75), 73% (19/26), and 77% (50/65), respectively. Use of whole blood resulted in unreliable progesterone concentration results by ELISA when compared to plasma progesterone concentrations measured by RIA (n = 140). Use of this ELISA test kit to determine canine ovulation date should start within three to four days after onset of proestrus and continue every other day until the first detection of medium concentrations (greater than 1 ng/ml, less than 5 ng/ml). Daily plasma testing during the time of transition from medium to high (5 ng/ml or greater) concentrations was essential for determining ovulation date. The second or third day after the first appearance of high plasma progesterone concentrations using this kit should be the day of breeding for optimal reproductive performance.

Animals↗