Biochemistry and experimental biology最新文献

Four trials involving 192 Large White X Landrace pigs were conducted to investigate the effect of wide variation of dietary methionine, lysine and caloric density on the activity of hepatic glutamate-oxalate ad glutamate-pyruvate transaminases. Results of the study show that: The activities of the two transaminases were influenced by the nutritional treatments. GOT and GPT activity exhibited significant positive and negative quadratic relationship respectively with dietary methionine levels. Both GOT and GPT activities decreased with increasing caloric density or palm oil level of the diet. In weanling pigs, both GOT and GPT exhibited significant negative quadratic relationship with dietary lysine levels and were also significantly influenced by the sex of the animals. In older pigs, only GOT activity was significantly affected by dietary lysine levels. The correlation of GOT and GPT activities to dietary essential amino acids shows that hepatic enzymatic activities could be good indices of essential amino acid utilization.

Effect of feeding lysine and threonine deficient and supplemented rice diets to rats for fifteen days has been studied on the lipids of hepatic smooth (SER) and rough endoplasmic reticulum. The deficient diet reduced protein and phospholipids of SER where as it increased triglycerides contents of both SER and RER compared to rats fed the supplemented diet.

Pseudo-pregnancy was induced in S. fossilis fish with Progynon and the consequences were studied with special emphasis to the assay of anomalies, on the cytomorphological level. Anomalies included profuse clumping, precocious despiralization and stickiness.

1. The identification of cholesterol as a constituent in the genesis of coronary artery disease in man and experimental animals are well documented. 2. The hypolipidemic effects of Commiphora mukul (guggulu) and Alium sativum (Garlic powder) were screened in dog and Presbytis monkeys. 3. Progressive decrease in the mean values of cholesterol, triglycerides and phospholipids were conspicuous for forty eight hours following the administration of guggulu/garlic powder. 4. 25 mg/kg body weight garlic powder was more effective in lowering the serum cholesterol and triglycerides as compared with that of guggulu. 5. A comparative hypolipidemic action of the two compounds is discussed.

A procedure is reported which is well applicable for the quantitative determination of glycogen, especially in cases of a small glycogen content in a small amount of tissue. The method consists of extraction of glycogen by boiling potassium hydroxide, precipitation with ethanol, hydrolysis with sulphuric acid, and determination of the glycogen in form of glucose obtained with orthotoluidine.

Microcirculatory effects of intravenous administrations in the appropriate doses of phenoxybenzamine (POBA), phentolamine (PTA), nicotinic acid (NAc), trimetazidine (TMZ), dilazep (DZ), cepharanthine (CT), alpha-tocopheryl acetate (TP-A), and alpha-tocopheryl nicotinate (TP-N) as vasodilator agents were investigated in the subcutaneous tissue within a transparent ear chamber of the normal conscious rabbit. The intra-vital microscopic findings obtained following administration of the drugs were as follows: POBA, a marked and long-lasting vasodilatation without vasomotion (more than 1 hour); PTA, a quite brief vasodilatation followed by a marked and long-lasting vasoconstriction without vasomotion (more than 1 hour); NAc, a short-lasting vasodilatation with slightly blunted vasomotion (less than 10 minutes); TMZ, DZ, CT, TP-A, and TP-N, a similar notable and transient vasodilatation with vasomotion (about 1 hour or more). Some physiological implications on the microcirculatory changes induced by administrations of the drugs were discussed especially in relation to the significance of sustaining the rhythmic fluctuations of blood flow due to vasomotion.

This paper describes a new method for obtaining "in vivo" populations of homogeneous erythrocytes of a specific age. This method, proposed for experimental animals, is based on the induction of a large reticulocytosis (about 80%) by the administration of phenylhydrazine and the subsequent synchronized ageing of young red cells present, which is obtained by blocking the erythropoiesis with daily injections of Actinomycin D. The advantage of such a method over those published so far is that it produces substantial quantities of red blood cells of a specific age. A disadvantage however is that it is only possible to obtain cells of up to 30 days old.

Tb3+ has been tested as a probe to determine G + C per cent composition of DNA. DAPI, a fluorescent dye specific for A + T bases, has been employed at the same time as a complementary probe. Using calf thymus DNA (G + C = 40%; A + T = 60%), it has been found that the binding of the two dyes is independent, and that one binding site every 12,5 nucleotides exists for Tb3+ and one binding site every 8.3 nucleotides for DAPI. The simultaneous use of Tb3+ and DAPI allows therefore the monitoring of A-T, G-C sequences.