Biochemistry and experimental biology最新文献

In chick embryos, time of pipping is accelerated after repeated gassing the air cell with N2, CO2, or by sealing the egg shell in the area of the air cell with glue. Gassing the air cell with 95% O:2-5% CO2, or pure O2, was followed by a retardation of pipping. Furthermore, gassing with N2, or sealing the air cell with glue, exerted an accelerating effect on the decrease of hepatic glycogen and ATP. Following gassing with 95% O2-5% CO2, the reverse effect on glycogen and ATP was observed. It is suggested that the increase of the CO2/O2 ratio, occurring in the air cell at the end of incubation, acts as a stimulus for both pipping and metabolic changes in the liver.

The fatty acid composition of extracts from organs of rats fed with normolipidic diets-either olive oil or sunflower margarine-has been determined in order to evaluate the influence of alimentary lipids on the storage of fatty acids in the animals liver, kidney, heart, adipose tissue and brain. The data obtained clearly showed that elaidized feeds caused an increase of trans-fatty acids in all the organs, although in different relative amounts, unrelated with the increase of these geometric isomers in the diet. Moreover it was found that the administration of trans fatty acid rich diets influenced the accumulation of essential fatty acids in the organs.

The fatty acid composition of total lipids, triglycerides, free fatty acid pool, esterified cholesterol, phosphatidyl choline, and phosphatidyl ethanolamine of mammary tissue of lactating and nonlactating buffalo has been studied. The distribution of long chain triglycerides, free fatty acids free cholesterol and esterified cholesterol in nonlactating mammary tissue was 76.1,4.2,4 and 0.5 percent of total lipids respectively and in lactating mammary tissue it was 68.3, 1.2, 2.7 and 0.3 percent respectively. Short chain triglycerides constituting about 6.6% of total lipids and could be detected only in lactating mammary tissue. Among phospholipids, phosphatidyl choline, phosphatidyl ethanolamine and sphingomyelin constituted about 39.4, 21.5 and 15.6 percent respectively of total phospholipids in nonlactating tissue and 39.3, 22.6 and 10.7 percent respectively in lactating tissue. All the major fatty acids viz myristic, palmitic, stearic acid oleic were present in various lipid components of both lactating and nonlactating mammary tissue. Linoleic acid was present only in the lactating mammary tissue. Differences were observed in the distribution of fatty acids in lipid components of lactating and nonlactating mammary tissue.

Administration of phenobarbital to female rats significantly increased the levels of liver monoenoic, dienoic and tetraenoic PC and in plasma it raised phosphatidyl choline and its monoenoic and dienoic species and decreased triglyceride levels. Significant reductions in the incorporation of NaH2 32PO4 into monoenoic and dienoic PC were observed in phenobarbital treated rats. Phenobarbital administration significantly increased the incorporation of 14CH3-methionine into tetraenoic and hexaenoic PC of liver. In plasma the incorporation of NaH2 32PO4 into monoenoic and dienoic PC in phenobarbital treated rats was not affected but that of 14CH3-methionine incorporation into tetraenoic and hexaenoic PC was suppressed as compared to the control. Phenobarbital enhanced PC synthesis Via N-methylation of PE and depressed via CDP-choline pathway.

1. The activity of the enzyme Fructose 1:6 Bisphosphatase (FDPase) was studied in the liver and testis of adult goats and rats. No significant difference in the enzyme activity was observed between liver and testis of rats. Highly significant differences (P less than 0.01) were observed between the activity of goat liver and goat testis, goat liver and rat liver, goat testis and rat testis; the activities being higher in goat tissues. 2. Homogenization of the tissues with water, 0.05 M lactate buffer (pH 3.5), 150 mM KCl and 0.34 M sucrose yielded highest activity with water and lactate buffer followed by Sucrose and KCl. 3. 10 microM of Fe2+ and 45 microM of Zn2+ decreased the enzyme activity of rat testis by 39% and 93% respectively. 4. The rate of hydrolysis of FDP with respect to time in rat liver and testis was a first order reaction. Linear kinetics of the substrate hydrolysis was observed up to 90 min. No substrate inhibition of the enzyme activity was observed up to 50 microM of the substrate. Km of rat liver and testis FDPase were 8.3 microM and 10.5 microM respectively.

The PHA response of blood lymphocytes from lung cancer patients was found to be diminished in comparison to normal. Sera from these patients inhibited the blastogenic response of blood lymphocytes from normal subjects. Normal sera could restore to various levels the diminished PHA response of lymphocytes from lung cancer patients. The results suggest that the immunosuppression seen in lung cancer may be mediated by a factor (s) in the serum which might bound reversibly to a certain subpopulation of T-cells and permanently to another and or some other inhibitory mechanism does exist.

Tryptophan pyrrolase activity has been assayed in crude liver homogenates prepared from rats submitted to chronic ethanol treatment. The results show that chronic ethanol treatment causes a marked reduction in the apoenzyme form of tryptophan pyrrolase. This reduction can be reversed by administration pyridoxine hydrochloride (100 mg/kg i.p. pro die for 8 days). Since chronic ethanol treatment increases cellular levels of NADH and NADPH which are known to inhibit tryptophan pyrrolase activity, it is suggested that the potentiating effect of pyridoxine might be due to the maintenance of normal ratios of cellular NAD+/NADH and BADP+/NADPH. In ethanol treated rats, pyridoxine was as effective as fructose, a regenerator of NAD+ and NADP+ in maintaining control levels of the apo-[tryptophan pyrrolase].