ABSTRACT
AIM To investigate the effect of particle size and high speed flow of helium gas on the systemic absorption of indomethacin using a needle-less injection system. METHODS Poly-L-lactic acid microspheres containing indomethacin was prepared by the o/w solvent evaporation technique. After anesthetizing the male hairless rat, microspheres filled in the tube cartridge was accelerated by a stream of helium gas at various velocity in the HeliosTM gun system, and then was introduced to the abdominal skin. RESULTS Introduction of indomethacin to the hairless rat skin was proportionally increased with enhancing the helium pressure (supersonic flow). Bioavailability and Cmax were also dependent on the helium pressure. CONCLUSION This method can be used to deliver the powered drug and/or microparticulate systems into the skin tissues and the systemic circulation.
ABSTRACT
117 guinea pigs were divided into groups, receiving 1mg, 5mg, 50mg and 100mg Vit C per os daily respectively in 2-4 weeks. There were conducted four experiments: (1) the effect of different vitamin C levels on the cold tolerance and adaptation in guinea pigs; (2) effect of large dose of vitemin C on sudden and long time exposure to cold: (3) the action of vitamin C, in large dose and short time in combination with hormones, on cold tolerance of guinea pigs; (4) effect of large dose of vitamin C on the myocardial enzyme activity, during the process of cold adaptation. Rectal temperature, body weight, weight and vitamin C contents of adrenal glands, the excretion of urinary 17-Ketostero'ids, activity of myocardial succinic dehydrogenase and cytochrom C oxidase were observed. The results revealed that large dose of Vitamin C per os might lessen the lowering of rectal temperature and body weight after exposure to cold; promote the activities of myocardial enzymes. Better results were obtained with combination of vitamin C with cortisones. It was noted that large dose of vitamin C apparently increased and accelerated the tolerance and adaptation of organisms to cold.
ABSTRACT
Although the relation between vitamin deficiency and protein metabolism has been reported by earlier investigators, no study of the effect of riboflavic deficiency on the regeneration of tissue proteins has yet been made. This paper is a report of an investigation on the effect of riboflavin deficiency upon the regeneration of liver, muscle and total circulating plasma proteins in adult rats. The riboflavin store in the body of rats was first depleted by feeding riboflavin-free diet in the course of 36 days. Then moderately severe deficiency symptoms of both riboflavin and protein were induced during a period of 12 days by a riboflavin- and protein- free diet. After the deficiency of riboflavin and protein had been established, the depleted rats were then treated with complete and riboflavin-free diets for an appropriate period. The results are listed as following.1.The omission of riboflavin from normal complete diet of adult rats caused a regular reduction of weight and food consumption during the depletion period, the severity of which was markedly increased when protein was withdrawn from the riboflavin-free diet as well.2.The regeneration rate of liver and total circulating plasma proteins of both riboflavin and protein deficient rats decreased slightly when treated with riboflavin-free but proteinadequate ration. While the muscle protein was lost in greater amount instead of regenerated.The experimental work was made in former National Institute of Health Nanking.
ABSTRACT
A comparative study of the methods of biological assay of vitamin A with rats was carried out in this experiment. The body weights and vitamin A levels in the blood and liver of the deficient animals were measured at different time intervals after they were supplemented with various doses of this vitamin. The increase of body weights of the rats was lineally correlated with the logarithms of dosages of vitamin A supplemented within the range of 1-12 ?g; while the. vitamin A levels in blood or liver was also lineally correlated with it within the range of 1-10 ?g. Moreover, the vitamin A contents in blood and liver themselves were closely interrelated to each other. All of the correlations were statistically significant. The procedure for the biological assay of vitamin A recommended by the Pharmacopoeia of the People's Republic of China was discussed.