| This article aims to study distribution of beta-carotene in rats' tissues by isotopic trace technique.In the first experiment, the biological synthetic method of 3H-β -carotene (3H- βc) had been established. The Spirulina maxima was grown in Zarrouk's medium using initially H2O and subsequently 3H2O enriched water (specific activity 6mCi/L). After suspension cultured in normal Zarrouk culture medium for producing maximum biomass and P -carotene ( P c), Spirulina was kept in radioactive culture medium 2 weeks in which some H atoms of the Spirulina was replaced by 3H atoms of the culture. Then, tritium labeling P c could be extracted from the Spirulina by chromatogram. The radioactive culture medium could be used in several cycles for metabolic labeling of carotenoids whereby the cost of production was reduced. At last, purity of 3H-β c was about to 95% and specific activity was 2.4 10 4Ci/mol.In the second experiment, n-octanol/water partition coefficient (Kow)of β c was determined for describing lipophilicity quantitatively with shake-flask method and HPLC. In addition, water solubility of 0 c was estimated by regression equation. The result showed the 1gKow was 3.98 0.27 and the lgSw was -4.406 0.39.In the third experiment, distribution of 3H-βc in rats was determined. After injecting 3H- βc into their abdominal cavity for 84h, the liver and the spleen accounted for 46.54% and 21.90%, respectively, of the total recovered 3H radioactivity in rats. In addition, a little radioactivity also can be detected in heart, kidney, brain, chest gland and adrenal. No radioactivity was found in muscle and fat. At the same time, negative correlation was discovered between distribution of radioactivity and fat concentration in rats' tissues. The correlation coefficient is -0.9170. The results suggest that, in different animals, the amount of P c lies on the deposit ability of β c in the fat and P c is likely to bound with germ plasm in animal cell according to nature of physical chemistry.
|
PDF Full Text Request