[Testing of vitamin E in the newly developed Czechoslovak preparation Trivitamin]. / Testace vitamínu E v cs. vývojovém preparátu Trivitamin.

Experiments were performed to test the newly developed Czechoslovak preparation Trivitamin, including the comparison of its effects at intubation onto the tongue root and at muscular implantation; these effects were compared with the i. m. administration of Axetocal. The levels of vitamin E in the blood of pigs were examined as influenced by the above treatments. The best utilization was obtained in the Trivitamin preparation given to the pigs intramuscularly. Peroral administration ranked second, whereas the lowest reaction was obtained from Axetocal at intramuscular administration. We hope that a good aqueous medium in which the vitamin is suspended in the main prerequisite for a high utilization rate of vitamin E is the model test with the Trivitamin preparation.

[Vitamin C levels in the early postnatal period in calves and their mothers]. / Vitamin C v raném postnatálním období u telat a jejich matek.

The dynamics of L-ascorbic acid was studied in 68 cows and 91 calves at an age from one to ten days in the period from November to April. The study was conducted in two maternal stocks in a supply area of a large-capacity calf-house located in the beet-growing region. L-ascorbic acid in the blood serum was determined accoring to King. The lowest average levels of L-ascorbic acid were found in February (cows 0.35 mg%, calves 1.02 mg%), and the highest in April (cows 1.00 mg%, calves 2.52 mg%). The level of L-ascorbic acid descended during ontogenesis from the value found at birth (6.72 mg%); the values of the first postpartal day are significantly higher in comparison with all the remainind observations. The results constituted a basis for a working hypothesis on the importance of colostrum as an exogenous source of L-ascorbic acid for calves.

Macromolecular synthetic activity in mice regenerating liver after ethylnitrosourea injection.

The present report is a continuation of our previous studies on the biochemical mechanisms of carcinogenesis; studying the nature of interactions taking place between Ethylnitrosourea and DNA, RNA and protein of various stages of their synthetic activity. As a model system we chose partially hepatectomized mice live 36 hrs after surgery. Synthetic macromolecule activity in the remaining liver segment was determined by means of 3H-thymidine, 3H-uridine and 3H-leucine. We observed complete depression of DNA synthetic activity (immediately after Ethylnitrosourea administration it remained depressed almost through out the whole period of our observations) while protein synthetic activity was highly elevated. Qualitative changes of soluble proteins which were analyzed by isoelectric fractionation on 5% polyacrylamide after previous 3H- and 14C-leucine incorporation, could not be detected. Our biochemical data are correlated with histological studies and with the tumour incidence following the Ethylnitrosourea treatment of partially hepatectomized mice in the course of long-term experiments. The results provide guideline for further analysis, which should be modified according to the information concerning Ethylnitrosourea carcinogenesis induced 36 hours after partial hepatectmoy.

Simultaneous determination of LH activity in blood serum of sheep during three synchronized oestrous cycles by Bio and Ria method.

LH activity has been in 6 Merino sheep by means of the biological (Bio) and radioimmunological (RIA) test during three subsequent synchronized oestrous cycles. The vaginal sponges were impregnated with 30 mg chlormadinone acetate. The results obtained by the two afore mentioned methods are similar. Oestrous appeared in the average within 96 hours after removal of the sponges. The first increase of LH activity (Bio) was found to occur within 48--72 hours after removal of the sponges (270--400 IU/100 ml serum), the second increase within 15--16 days (450-570 IU/100 ml) and the third within further 16 days (390--590 IU/100 ml serum). The values obtained in the first oestrous cycle by RIA showed an LH peak within 62--110 hours after removal of the sponges (75--90 ng/ml in the second oestrous cycle 86--135 ng/ml and in the third one 58--60 ng/ml serum. In three animals no LH peak could be observed during the first, second or third oestrous cycle. The failure to prove LH peaks in three sheep during different phases of the oestrous cycles is explained by the fact that the synchronization led to heat which, however, did not result in fertile ovulation.

Inter and intra diurnal variations of DNA, RNA and protein synthetic activity in newborn, infant and young adult mouse livers.

The present report is a continuation of our previous studies on the observations of macromolecule precursors incorporated into the liver of newborn (1-10 days), infant (11-21 days) and young adult (41-50 days) old mice C57BLfemale X C3Hmale Fl and 3-hour interval circadian rhythm in livers of 15 day-old mice. 3H thymidine, 3H uridine and 3H leucine were used for studying incorporation into the macromolecules. DNA, RNA and protein were prepared by a modified Kirby's procedure. The data obtained indicate fluctuation of DNA activity approximately at 5-day intervals with a decreasing tendency up to 50 days of age. In 15-day-old mice, the peak of synthetic DNA activity was observed at 9.00 a.m. and the lowest values were found the next day at 6.00 a.m. Our results should provide fundamental data from which it would be possible to speculate whether the hepatocarcinogenic effect of different compounds with or without a special affinity to induce hepatoma may be correlated to different macromolecular synthetic activity.

Macromolecular turnover in mice (C57BL times C3H) liver, thymus and kidney after partial hepatectomy.

Studies have been presented concerning the definition of bioassay systems, in terms of macromolecular kinetics as it pertains in advance to ENU carciogenic sensitivity. Male mice (C57BL female times C3H male) 6 weeks of age were partially hepatectomized and labelled with thymidine 3-H, uridine 3-H and leucine 3-H as precursors for DNA, RNA and protein synthesis respectively. Specific activity of all these three parameters of liver, thymus and kidney were followed for 5 days at regular intervals, and for 6 weeks at randomly chosen intervals. The goal of this study which we obtained, is a three-phased curve in liver for each macromolecule studied; RNA synthesis reached its first peak 18 hours, protein synthesis 24 hours, and DNA synthesis 30 hours after partial hepatectomy. Synthetic macromolecular turnover in other organs (thymus, lung, kidney, brain) were not affected in a similar way, inspite expecting some factors of a humoral nature. An accurate knowledge of the timing in macromolecular synthesis after partial hepatectomy in mice is an essential preliminary study for the development and definition of a model protocol for ENU--single dose having approximately 10-15 minutes half-life carcinogenic response.