Search PubMed⌕ Search

Biomedical subjects

I Wolinsky

Publications and source records attributed to I Wolinsky.

18 recordsLinked to original sources
PubMed1992

Ornithine supplementation and insulin release in bodybuilders.

Ornithine supplementation has gained popularity with athletes because of its alleged potential to release anabolic hormones, factors governing skeletal muscle hypertrophy. Three female and nine male bodybuilders served as subjects in a study to test the effectiveness of oral ornithine in bringing about the release of insulin, an anabolic hormone. After an overnight fast, subjects were administered 40, 100, or 170 mg.kg-1 L-ornithine.HCl by mouth in a random fashion on three consecutive Saturday mornings. Blood samples were drawn at baseline (T = 0), 45, and 90 min afterward. Serum ornithine levels were elevated (p < 0.01) at T = 45 and 90 min for all three dosage levels. However, serum insulin did not change from baseline levels at any dose of ornithine. The present findings show that ornithine is not an insulin secretagogue.

Adult↗
PubMed1989

Suppression of opiate withdrawal by cyclosporin A and dietary modification.

It has been demonstrated in a murine model that a defined diet (Purina Basal Diet 5755) has immunosuppressive effects similar to cyclosporin A (CsA). It was also shown that CsA treatment in opiate dependent rats can attenuate the severity of opiate withdrawal. In this study, an opiate dependence model was established in Balb/c mice to assess the effects of the 5755 diet and CsA on morphine withdrawal - a CNS mediated phenomenon. Three groups of mice were used; a chow-fed control group (Purina 5008), a chow fed CsA treated group, and a group maintained on the 5755 diet. Morphine dependence was established by subcutaneous implantation of a 100 mg morphine base pellet under ether anesthesia. Seventy-two hours after pellet implantation, withdrawal was precipitated by a single injection of the opiate antagonist naloxone (2 mg/kg ip). Two indicators of withdrawal were assessed; jumping and diarrhea. The data demonstrated that both CsA and the 5755 diet resulted in significant attenuation of withdrawal symptoms with the 5755 diet being the most effective of the two. These findings suggest that immune modulation elicited by the 5755 diet and CsA treatment has a direct impact on the CNS opioid function.

Animals↗
PubMed1989

Lipid peroxidation activation and cytochrome P-450 decrease in rat liver endoplasmic reticulum under oxidative stress.

Iron loading was associated with development of oxidative stress, viz, decrease in tocopherol content and an increase in amount of lipid peroxidation products but only slight, if any, decrease in cytochrome P-450 content. Combinations of iron loading with other stress-inducing treatments (exhaustive physical exercise and hyperoxia) caused marked decreases in cytochrome P-450 content. Thus, a combination of factors favoring development of oxidative stress, but insufficient to exert a damaging effect on the cytochrome P-450-dependent detoxification system when acting alone, may become quite potent when acting in concert.

Animals↗
PubMed1989

Oxidative stress leads to inhibition of calcium transport by sarcoplasmic reticulum in skeletal muscle.

Iron administration results in the development of oxidative stress in skeletal muscles, as evidenced by increases in amounts of lipid oxidation fluorescent end products, decreases in vitamin E concentration, and inhibition of calcium transport by sarcoplasmic reticulum. Exhaustive physical loading or hyperoxia, or their combination, does not lead to apparent modification in calcium transport by sarcoplasmic reticulum in skeletal muscle homogenates. However, physical loading or hyperoxia does in fact induce oxidative stress since they magnify the effect of iron loading on the inhibition of calcium transport.

Animals↗
PubMed1989

Urinary 3-methylhistidine excretion increases with repeated weight training exercise.

This investigation examines the effect of progressive resistance weight training exercise on urinary 3-methylhistidine (3-MH) excretions in untrained subjects. For 19 consecutive days, 11 males were fed a weight maintenance, lactovegetarian diet which contained the Recommended Dietary Allowance (0.8g.kg-1.d-1) for protein. No exercise was performed for the first 7 d of the study. Subjects were strength tested on day 8 and performed upper and lower body weight training exercises from days 9-19. Complete, 24-h urine collections were obtained from each subject on a daily basis. Samples were assayed for creatinine and 3-MH. Stable baseline 3-MH values were present during the pre-exercise control period. Significant increases in 3-MH occurred by study day 11, which was the third day of weight training exercise. This was true regardless of whether the data were expressed by daily excretions (microM.d-1; P less than 0.01), per unit of body weight (microM.kg-1.d-1; P less than 0.005), or per unit of creatinine excretion (microM.g Creat-1.d-1; P less than 0.001). Since urinary 3-MH is an index of actin and myosin catabolism, these data support the hypothesis that the rate of skeletal muscle degradation is increased during strength building exercises.

Adult↗
PubMed1986

Failure of weight training to affect urinary indices of protein metabolism in men.

It is commonly believed by some athletes that strength building exercise "tears down" skeletal muscle tissue, thereby enhancing the dietary need for protein, but this has not been demonstrated. Ten college-age males served as subjects in a 15-d, controlled feeding study. The men were 23.1 +/- 2.2 yr old (mean +/- SD), 177 +/- 5 cm in height, and 71.7 +/- 9.1 kg in body weight (study days = 1 to 15). The lacto-ovo-vegetarian diet provided 0.9 g/kg protein and 15.1 +/- 0.4 MJ (3,604 +/- 104 kcal) . d-1 energy (study days = 6 to 15). On days 8 and 12, subjects participated in a standardized strength building, weight training exercise regimen. Post-exercise days 9 to 11 and 13 to 15 were designated for recovery. Daily (24-h) urine collections were analyzed for ammonia, creatinine, 3-methylhistidine, total nitrogen, and urea. There was no acute (24-h) effect of weight training exercise on any excretion levels. In particular, urinary 3-methylhistidine excretion data indicate that skeletal muscle protein catabolism was not changed by isolated bouts of weight training exercise.

Adult↗
PubMed1985

Effects of dietary protein concentration on trace minerals in rat tissues at different ages.

Copper, iron and zinc concentrations were measured in tissues of young (2 mo), mature (14 mo) and aged (26 mo) male Fischer rats fed either a normal protein (16% casein) or high protein (32% casein) diet for 30 d. Spleen copper concentrations decreased with maturity but were not affected by dietary protein level. Age, dietary protein and age X protein interaction affected spleen iron concentrations. Splenic iron was increased significantly only in mature and aged rats fed the normal protein diet. High protein-fed aged rats had decreased splenic zinc. High protein feeding increased renal zinc in the young and aged rats compared to normal protein feeding. At both protein levels, liver iron increased in the mature rats. Upon aging, zinc levels in the heart increased in the normal protein group and decreased in the high protein group. A significant interaction between age and protein was observed on heart zinc. Thus, the concentrations of tissue trace minerals are affected by age, dietary protein and protein X age interaction in young, mature and aged male rats.

Aging↗
PubMed1978

Lysozyme levels in tissues of iron-deficient rats.

Fats were fed either diets sufficient (300 ppm) or insufficient (5 ppm) in iron for 10 weeks. The iron-deficient animals had lowered hemoglobin and hematocrit levels and higher levels of kidney lysozyme activity than did control animals. There were no significant changes in serum and spleen lysozyme activity levels.

Anemia, Hypochromic↗
PubMed1978

Iron deficiency hyperlipidemia in 18-day-old rat pups: effects of milk lipids, lipoprotein lipase, and triglyceride synthesis.

Three levels of iron (5, 29, 307 ppm iron) were fed to rats from conception through the 18th day of lactation. Dams in the 5 ppm iron group and pups in the 5 and 29 ppm iron groups developed anemia characterized by lower hemoglobin and hematocrit values than control animals. Liver and spleen levels of iron in dams and pups in the 5 and 29 ppm iron groups were lower than in the 307 ppm iron groups. Milk iron was lower in the 5 ppm iron group than in the 29 and 307 ppm iron groups. Pups in the 5 ppm iron group had hyperlipidemia characterized by elevated serum triglycerides, cholesterol, and phospholipids. Milk lipids and post-heparin plasma lipoprotein lipase levels in pups did not differ among experimental groups. Triglyceride and CO2 production from [U-14C]glucose were significantly greater in the iron-deficient pups than in control pups. Hyperlipidemia in 18-day-old iron-deficient rat pups appears to be related to increased endogenous production of triglycerides.

Anemia, Hypochromic↗
PubMed1976

The effect of fluoride on bone of rats fed diets deficient in calcium or phosphorus.

Four groups of weanling rats were fed for 2 weeks on a diet sufficient or insufficient in calcium and/or phosphorus. Each group was divided into four subgroups which were offered distilled water supplemented with 0, 50, 75, or 150 ppm fluoride. High levels of fluoride in drinking water inhibited weight gain. This inhibition was less in rats deficient in phosphorus than when normal-phosphorus diets were offered. At a low level, fluoride was without any effect on bone ash, thickness of femoral cortical bone, and mechanical strength, as measured by maximal load, ultimate stress to breaking, and limit of elasticity. Modulus of elasticity was decreased. At higher levels fluoride tended to decrease most of these parameters, except in rats deprived of both calcium and phosphorus. The effect of fluoride was modified by lack of dietary calcium and/or phosphorus and appeared to be weaker in rats deficient in these nutrients. Lack of dietary calcium and/or phosphorus decreased bone strength more than did fluoride content of water and of bone mineral. Concentration of bone ash and thickness of femoral cortical bone were closely correlated with parameters of mechanical strength.

Animals↗
PubMed1975

Effect of repletion with dietary calcium on composition and mechanical properties of bone of calcium-deprived rats.

Four groups of rats were fed a low-calcium diet (0.02%) and two groups a normal calcium diet (0.50%). After 2 weeks one group from each dietary calcium level was sacrificed and the femurs examined. The remaining three groups which had been kept on the low-calcium diet were then given diets richer in calcium: 0.25, 0.35 and 0.5%. The remaining group on the normal calcium diet continued receiving it. After two more weeks all animals were sacrificed and their femurs examined. Rats fed the low-calcium diet lagged behind in weight gain; ash content, breaking strength, and modulus of elasticity of their femurs were much lower than those of animals on the normal calcium diet. Feeding diets with increasing calcium content increased bone ash and improved mechanical properties. However, improvement of breaking strength and elasticity did not parallel strictly increases in mineralization. Repletion with a normal calcium diet (0.50%) failed to increase bone ash to normal levels but mechanical properties were improved by repletion with substantially lower dietary calcium levels. Maximal breaking strength was obtained by repletion feeding with a dietary calcium level which failed to increase bone ash. It seems that factors other than mineralization determine breaking strength and elasticity of bone recovering from calcium deprivation.

Animals↗