[The effect of rolitetracycline on the level of nonesterified fatty acids, phospholipids, and triacylglycerols in ischemic damage to the myocardium]. / Vliianie rolitetratsiklina na uroven' neésterifitsirovannykh zhirnykh kislot, fosfolipidov i triatsilglitserinov pri ishemicheskom povrezhdenii miokarda.

Myocardial ischemia developed in rabbits after ligation of coronary artery within 60 min. Single dose of rolytetracycline 40 mg/kg was administered intravenously before or after ligation. Alterations in content of unesterified fatty acids and phospholipids were studied in blood serum as well as of unesterified fatty acids, phospholipids and triacyl glycerols--in the myocardium. After ligation of coronary artery content of unesterified fatty acids and phospholipids was increased 2-fold in blood serum as compared with control values, while in the ischemic myocardium these substances were increased more than 2-fold and triacyl glycerol--about 7-fold. Administration of rolytetracycline before ligation of the artery led to a decrease in content of unesterified fatty acids and phospholipids in blood serum down to control values; the ligation-induced high content of triacyl glycerols and phospholipids in the myocardium was also decreased, while alterations in unesterified fatty acids content were not similar. Rolytetracycline administered after the artery ligation caused a decrease in content of unesterified fatty acids but triacyl glycerols were markedly increased. The antibiotic did not affect the lipid content in nonischemized tissues of myocardium.

Effects of ovine prolactin in infant rats.

The objective of this study was to determine the effects of ovine prolactin (oPRL) on body growth and the content of RNA, DNA and protein in liver, brain and heart muscle in rat pups. Suckling rats were daily injected from 3rd to 28th day of life with 1 microgram of oPRL/g body weight. Our results show that oPRL administration evoked higher body weight gain up to 8th day of life (p less than 0.05). There was significant (p less than 0.05) increase of DNA liver content and significant decrease (p less than 0.001) of RNA/DNA ratio in the hepatocytes. The findings suggest that prolactin influences growth rate of rats in the early postnatal period of life.

Effects of bovine growth hormone in suckling lambs.

The objective of this study was to determine the effects of bovine growth hormone (bGH) on body growth of suckling lambs. Suckling Merino lambs (fed on milk replacer from 4th day of life) were daily injected from 10th to 38th day of life with 80 micrograms bGH/kg b.w. Only insignificant increase of body weight was observed after 4 weeks of GH treatment. After 31st day of life body weight gain in the experimental lambs was significantly higher. It can be concluded that bGH increases body weight gain of lambs in 2nd month of life. It is probable that growth rate of sucklings is limited only by biological and biochemical capabilities of the organism and it can be hardly influenced by exogenous hormonal manipulation.

Effects of bovine growth hormone in infant rats from reduced litters.

The objective of this study was to determine the effects of growth hormone on body growth and the content of RNA, DNA and protein in liver, brain and heart muscle in rat pups from reduced nests. Suckling rats raised in litters of 4 youngs were daily injected from 3rd to 28th day of life with 1 microgram of bGH/g body weight. Our results show that GH administration evoked higher body weight gain and increase of tail length after 23rd day of life. There was significant increase of liver content of nucleic acids and protein. This GH-responsivity of pups from reduced nests might be related to differences in their metabolic profile and accelerated somatic and psychosocial development in comparison to normal youngs.

RNA content of neurons in the ventromedial nuclei and lateral hypothalamic area relative to feeding status.

The total RNA content of hypothalamic and cortex neurons in relation to the feeding status of adult male Wistar rats was studied. Experimental conditions including food deprivation (12 and 24 hours) and relative satiation (short-term refeeding, glucose or glycerol administration) changed in different ways the total RNA content of the neurons in the ventromedial hypothalamic nuclei (VMH) and in the lateral hypothalamic area (LHA) with respect to fasting or satiety. Only the long-term absence of food (24 hours) significantly increased the total RNA content of the VMH cells, while the RNA content of the LHA neurons significantly decreased in both the 12 and 24 hr fasted rats compared with those fed ad lib. The sixty minute free access to food after 12 or 24 hours of fasting fully reversed these changes. The short-term food intake significantly increased the RNA content of the LHA cells of the 12 and 24 hr fasted animals while the total RNA content of the VMH neurons significantly decreased only in the 24 hr fasted rats. The effect of glucose and glycerol administration on the RNA content of the LHA neurons (in 12 hr fasted rats) was similar to the effect of refeeding. One hour after giving glucose (1 g/kg b.wt.) or glycerol (300 mg/kg b.wt.) the total RNA content in the LHA neurons significantly increased. No changes in RNA content were observed in the neurons of the cortex when comparing the experimental and control rats. The results demonstrated the close relationship between the RNA content of the hypothalamic neurons and the feeding status.(ABSTRACT TRUNCATED AT 250 WORDS)