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Biomedical subjects

J Simek

Publications and source records attributed to J Simek.

At least 127 records · Page 7Linked to original sources
PubMed1981

Effect of realimentation and triiodothyronine on DNA synthesis in intact and partially resected rat liver.

Whereas DNA synthesis in the liver of rats with permanent access to food fell markedly between the 72nd and 96th hour after partial hepatectomy, the decrease in the same post-operative interval in rats realimented after 3 days' starvation was less pronounced. The difference between the values in the control and the experimental group 96 hours after partial hepatectomy was statistically significant for p less than 0.01). In rats given glucose after the operation, 24 hours' realimentation caused a nonsignificant increase in DNA synthesis. The difference between the values 96 h after partial hepatectomy in this group and in the group fed the whole time on the standard diet was statistically significant for p less than 0.001. The administration of triiodothyronine (200 microgram/kg i.g.) to the above groups of rats at the outset of realimentation did not affect the development of changes in liver DNA synthesis. It likewise had no effect on the outcome of the realimentation of rats with an intact, unresected liver fed 3 days on plain glucose. In the intact control rats fed the whole time on the standard laboratory diet, triiodothyronine produced a distinct increase in liver DNA synthesis (p less than 0.01).

Animals↗
PubMed1980

Effect of realimentation after several days' pure carbohydrate intake on DNA synthesis in regenerating rat liver.

The authors studied the effect of realimentation after several days' isolated glucose or fructose intake on DNA synthesis in liver regenerating after partial hepatectomy (PH) (65-70%) or after carbon tetrachloride (CCl4) poisoning 1.5 ml/kg. Two days before PH or the administration of CCl4 and two days after, the experimental rats were given glucose (50% solution) of fructose (50% solution) as the only source of energy. Rats with PH were then fed for one day on a standard laboratory diet (25 cal% protein) or a high protein diet (81 cal% protein). Rats with CCl4 liver damage were fed for one day on the standard laboratory diet only. In the rats given glucose, liver DNA synthesis and the total amount of these nucleic acids in the liver 48 hours after CCl4 administration was lower than in the controls or the rats given fructose. In all the experimental groups (PH and CCl4), stimulation of liver DNA synthesis was observed after one day's realimentation. The total DNA content of the liver of rats with PH rose markedly during realimentation. The experiments indicate that the regenerative activity of damaged liver can be influenced by the nutritional regimen.

Animals↗
PubMed1980

Influence of antithymocytic serum on the regenerating activity of the liver after partial hepatectomy in mice.

In experiments on mice the effect of rabbit-anti-mouse antithymocytic serum on the growth of the liver and on the onset of proliferating activity of the liver after partial hepatectomy was studied to elucidate the question of assumed participation of the lymphoid system in the proliferation of hepatic tissue. Administration of three doses of antithymocytic serum (0.1 ml/10 g) by the i.p. route in 24 hour intervals led to a marked increase of the weight of the spleen and increase of DNA synthesis in liver of non-operated mice. Administration of serum 24 hours before partial hepatectomy (PHE) concomitantly with PHE and 24 hours after PHE did not influence substantially the rate of DNA synthesis in the regenerating liver 34 and 48 hours after PHE and did not influence the mitotic index of hepatocytes. In the livers of mice to whom antithymocytic serum was administered proliferation of cells of the lymphocyte series and phagocyte activation occurred. These cells were located in the hepatic sinuses and periportal areas. Antithymocytic serum--contrary to chemical immunosuppressive substances--does not exert an inhibitory action on regeneration of hepatic tissue; alone does not even cause inhibition of the lymphoid system which could exert a negative effect on regeneration of the liver.

Animals↗
PubMed1978

Effect of realimentation after several days' isolated glucose or fructose intake on DNA synthesis in rat liver.

Marked stimulation of liver DNA synthesis was observed in rats given an isolated glucose or fructose diet for 4 days and theen refed one day on diets with different protein contents. The strongest stimulatn effect was found in rats refed, after an isolated glucose intake, with a high protein diet (81 cal%). The stimulant effect of refeeding on liver DNA synthesis was far less pronounced in rats subjected to several days' starvation before realimentation than in rats given a carbohydrate diet. The stimulant effect of realimentation after an isolated glucose intake was distinctly enhanced if triiodothyronine (50 microgram/100 g b.w., i.g.) was administered just before the change to a high protein diet. The increase in liver DNA synthesis in rats fed three days on fructose before undergoing partial hepatectomy was the same as in the controls. In rats given glucose prior to partial hepatectomy, the post-operative increase in DNA synthesis was partly inhibited.

Animal Nutritional Physiological Phenomena↗