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Biomedical subjects

M L Sunde

Publications and source records attributed to M L Sunde.

At least 73 records · Page 4Linked to original sources
PubMed1977

A mutual protective effect of mercury and selenium in Japanese quail.

Dietary interactions between methylmercury (Ch3Hg) and sodium selenite (Na2SeO3) were studied in Japanese quail. Addition of 0.35-6 p.p.m. Se to diets containing toxic levels of Hg (5-30 p.p.m. Hg) reduced the toxicity of methylmercury and increased the survival of Japanese quail. The survival increased with increasing levels of Se in the diet. Selenium as 6 p.p.m. did not cause any mortality in males and caused only relatively low mortality in females. However, 12 p.p.m. Se depressed the survival of quail, especially females. No consistent effect of Hg, Se or both was observed on body weight or feed consumption. High levels of Hg reduced egg production, fertility and hatchability, and the addition of Se lessened these effects of Hg. Selenium in the diet alone (6 or 12 p.p.m.) generally produced lower hatchability and a high percentage of deformed embryos, and 12 p.p.m. Se also depressed egg production. Addition of 5-15 p.p.m. Hg to such Se diets overcame these effects and reduced the percentage of abnormal embryos more than 50%. Analysis of tissues for total Hg showed that Hg was distributed in a pattern typical for alkyl mercurials. Hg levels in Se-protected birds equaled or exceeded the levels in those fed Hg without Se. Se levels in tissues were generally elevated by feeding Hg, especially in brain. Extremely high brain Hg levels, up to 58 p.p.m., were observed in birds fed 15 p.p.m. Hg plus 6 p.p.m. Se for 20 weeks prior to sacrifice. The levels of Se in the brain of these birds was elevated (4 p.p.m.), but not equimolar to Hg.

Abnormalities, Drug-Induced↗
PubMed1976

Is L-glutamic acid nutritionally a dispensable amino acid for the young chick?

The importance of dispensable amino acids for the chick was reinvestigated. Two-week chick weights were 75.7 g. and 143.7 g. when dietary nitrogen was provided solely by indispensable amino acids and by indispensable amino acids and 10% L-glutamic acid, respectively. Weight gain increased four-fold when L-glutamic acid was added to the mixture of indispensable amino acids. Plasma free amino acid concentrations were considerably decreased and total indispensable amino acid concentration (including cystine and tyrosine) was reduced to approximately a half or less with L-glutamic acid supplementation. Increments of L-glutamic acid as the sole nitrogen source for dispensable amino acids in the diet increased two-week weight gain proportionately over a range from 0 to 10%. When 10% of L-glutamic acid was included in the amino acid diet, growth rate was equivalent to that with a practical diet up to two weeks of age. The mixture of leucine, isoleucine, valine, lysine and arginine produced little growth promotion as a nitrogen source for dispensable amino acids. L-aspartic acid, L-alanine and the mixture of dispensable amino acids devoid of L-glutamic acid were found not as effective as L-glutamic acid. The estimate of effectiveness of L-aspartic acid, L-alanine and the mixture was approximately 80%, 60%, and 80%, respectively, of that of L-glutamic acid during first two weeks. Utilization of diammonium citrate for growth promotion varied with the amount used and the age of chicks. A combination of dispensable amino acids plus nominal levels of DAC was not as effective as glutamic acid during the first week but shortly after that, produced good gains. Even during the 3rd week or 4th week high levels of DAC alone did not produce normal gains of chicks. The activities and the subcellular distribution of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) in the liver of young chicks were measured. GOT activity was considerably higher than GPT activity. Initially, GOT activity was found primarily in cytosol, but the mitochondrial activity increased to 57% of total activity by day 10, whereas GPT activity was exclusively in mitochondria regardless of the age.

Alanine↗
PubMed1976

Conditions affecting plasma amino acid patterns in chickens fed practical and purified diets.

Experiments were conducted to investigate plasma free amino acid concentrations in the chick. After one hour of fasting, total plasma amino acid concentration decreased to approximately half of the full-fed value. Within three to six hours, most amino acids had returned toward the full-fed level but did not exceed it throughout a 48 hour period of starvation. However, after 48 hours fasting lysine, threonine, and isoleucine accumulated three-fold, two-fold and two-fold of the full-fed level, respectively. Serine and glutamic acid exceeded the full-fed level at three hours and then declined. Alanine reached its highest level after six hours of fasting and then declined. In full-fed chicks diurnal variations of plasma free amino acid concentrations were observed. The lowest and highest concentrations were observed at 11 a.m. and 8 to 11 p.m., respectively under a 24 hr-lighting. Reference plasma amino acid patterns are reported for chicks fed a practical diet ad libitum. In day-old chicks, concentrations of total amino acids, methionine plus one half cystine, lysine, and arginine were high. Alanine and glutamic acid concentrations were low. Most amino acid concentrations declined gradually during the first four weeks of life, but methionine plus one half cystine, phenylalaine, threonine and serine concentrations decreased sharply between two and four weeks. Lysine concentration continued to decrease in chicks fed the starter diet. At 20 weeks, plasma amino acid concentrations had decreased considerably except for methionine plus one half cystine and basic amino acids. The plasma amino acid pattern for chicks fed an isolated soybean protein diet was similar to that of chicks fed the practical diet.

Age Factors↗
PubMed1975

Effects of D-, DL-and L-glutamic acid on chicks.

Studies were conducted to investigate the effects of D-, DL-, or L-glutamic acid on the chick. Supplementation of levels of L-glutamic acid to an amino acid mixture containing adequate levels of all the indispensable amino acids plus cystine and tyrosine resulted in increased growth up to 10% L-glutamic acid in the diet. Chicks tolerated as much as 15% L-glutamic acid with no growth retardation. Supplementation of D-glutamic acid at levels of 3.75 or 5% resulted in growth depressions of 18 and 38%, respectively, at the end of a 2-week experiment. Significant growth-depressing effects of these levels of D-glutamic acid and 7.5% of DL-glutamic acid were also observed with an amino acid diet as well as an isolated soybean protein diet. The growth-depressing effect was most severe during week 2 of the experiment. Additional vitamins and amino acid supplements failed to reverse the growth-depressing effect. Plasma glutamic acid concentration was not altered by the inclusion of D-glutamic acid in the diet, but generally, plasma free amino acid concentrations were increased. This was especially true of arginine. Free glutamic acid increased in the kidney and was lowered in the liver. Free ammonia was increased in both the liver and kidney when the D form was included in the diet. Implications of these findings are discussed.

Amino Acids↗
PubMed1975

An evaluation of the nutritive value of new high protein oat varieties (cultivars).

Studies were conducted to evaluate the nutritive value of new high protein oat varieties using chicks and rats. Oat groats studied were Lodi, Dal, and Goodland; protein contents were 16.0, 18.0, and 20.5%, respectively. Increases in protein content were accompanied with an increase in indispensable amino acids. The lysine contents of Lodi and Goodland oat groats were 0.60 and 0.72%, respectively. With amino acid supplementation the 80% oat groats diets supported a growth rate of chicks comparable with that of a practical diet for up to 2 weeks. To correct amino acid deficiency, Goodland, Dal, and Lodi oat groats diets were supplemented with 0.55, 0.60, and 0.65% lysine and 3.2, 5.1, and 6.6% of a mixture of other amino acids. Omission of lysine from the amino acid supplement resulted in retarded growth and marked reduction of plasma free lysine concentration. For Goodland oat groats, the chemical score was 51. Protein efficiency ratio with rats was 2.2, which was increased to 2.4 by lysine and methionine supplementation, while protein efficiency ratio for whole egg protein was 3.4. The slope-ratio assay rendered a relative nutritive value of 59 for Goodland oat groats, assuming 100 for whole egg protein. This value was increased to 67 by lysine and methionine supplementation.

Amino Acids↗
PubMed1975

Dietary calcium levels in pre-lay and lay diets in Leghorn pullets.

Four experiments over a period of four years with 1350 first-year pullets were designed to determine the influence of the calcium and phosphorus levels in the pre-lay diets on the growing birds and on their subsequent performance. Several dietary calcium levels in the lay period were studied, as well as the interaction between the pre-lay and lay diets. During the growing phase the pullets fed 3.0% calcium and 0.4% phosphorus had significantly (P less than 0.05) lower body weight at 20 weeks of age than thep ulletsin the other pre-lay treatments. Feed consumption and feed efficiency were also adversely affected by this treatment, and sexual maturity was significantly (P less than 0.05) delayed. Early lay mortality from this treatment was evident. On the basis of egg production, egg weight, shell deformation and percent poorly shelled eggs (PSE) at point-of-lay, the pre-lay diets did not influence lay performance nor was there an interaction between any combination of pullet and lay diets. As the calcium levels of the lay diets increased, egg production, feed consumption and shell rigidity increased. The 1.5% calcium level did not maintain bone mineralization as compared to the 3.0 and 4.5% calcium levels. It was noted that shell quality on the basis of PSE and deformation does not begin to deteriorate immediately after the onset of production. In fact there is a short period of time where the egg shells improve and then there is a gradual decline in shell rigidity. The layers fed the lay diet containing 1.5% calcium produced eggs weighing an average of 57.4 g. This was significantly (P less than 0.05) lower than the eggs of the 2.3, 3.0 or 4.5% calcium fed groups which produced eggs weighing 59.1, 58.6 and 59.4 g. respectively.

Animal Feed↗
PubMed1972

Selenium: relation to decreased toxicity of methylmercury added to diets containing tuna.

Japanese quail given 20 parts per million of mercury as methylmercury in diets containing 17 percent (by weight) tuna survived longer than quail given this concentration of methylmercury in a corn-soya diet. Tuna has a relatively high content of selenium and tends to accumulate additional selenium when mercury is present. A content of selenium in the diet comparable to that supplied by tuna decreased methylmercury toxicity in rats. Selenium in tuna, far from being a hazard in itself, may lessen the danger to man of mercury in tuna.

Animal Feed↗