Search results for "STRAINS"

Effect of surfactants on Albendazole absorption

1991

Effect of Thyroid Hormones on Urea Biosynthesis and Related Processes in Rat Liver*

1988

The results of the few studies on the effect of the thyroid status on nitrogen metabolism have been inconclusive and/or contradictory. In an attempt to elucidate this important relationship, we have studied the effect of experimental hypo- and hyperthyroidism on urea biosynthesis and related processes. We have found that the capacity of the liver to synthesize urea was increased in hypothyroid rats, as were the activities of the urea cycle enzymes; there were also changes in the activities of some related enzymes and in the levels of intermediates and amino acids. Isolated hepatocytes from these rats showed an increased capacity for urea synthesis. In hyperthyroid rats the picture was more …

Effects of beta-adrenoceptor drug stimulation on various models of gastric ulcer in rats.

1982

Abstract 1. Experiments were designed to evaluate the effect of the pharmacological activation of beta-adrenoceptors on various models of gastric ulcer in the rat. 2. Pretreatment with the beta-adrenoceptor stimulant drugs, isoprenaline or salbutamol, significantly inhibited stress-induced gastric ulcers. This anti-ulcer effect was abolished by propranolol but not by atenolol, suggesting that beta 2-adrenoceptors mediate this response. 3. In the pylorus-ligation model, salbutamol inhibited lesion formation and reduced the intragastric content of hydrogen ions, histamine and pepsin although the latter was only affected with the higher dose of salbutamol. 4. Salbutamol also prevented the ulce…

Stereoselective drug distribution and anticoagulant potency of the enantiomers of phenprocoumon in rats

1977

Abstract The elimination, distribution and anticoagulant activity of S(—)-, R(+)-, and R,S(±)-phenprocoumon were determined in male Wistar-Lewis rats after intravenous injection of a single dose of 0·6 mg kg−1. From the plasma concentrations which elicited the same anticoagulant effect, S(—)-phenprocoumon was 4 to 5 times more potent than R(+)-phenprocoumon. The potency of the racemate was between those of the enantiomers. The mean biologic half-life of the S(—)-enantiomer was shorter (12·5 h) than that of R(+)-phenprocoumon (17·8 h). No differences were observed in the apparent volume of distribution. However, the mean liver: plasma concentration ratio was higher for the S(—)-(6·9) than fo…

Oxygenation of malignant tumors after localized microwave hyperthermia

1982

The oxyhemoglobin saturation (HbO2) of single red blood cells within tumor microvessels (diameter: 3-12 micrometers) of DS-Carcinosarcoma was studied using a cryophotometric micromethod. In untreated control tumors (mean tissue temperature approx. 35 degrees C) the measured values scattered over the whole saturation range from zero to 100 sat. %, the mean being 51 sat. %. Upon heating at 40 degrees C for 30 min, the oxygenation of the tumor tissue significantly improved as compared with control conditions. After 40 degrees C-hyperthermia a mean oxyhemoglobin saturation of 66 sat. % was obtained. In contradistinction to this, after 43 degrees C-hyperthermia the tumor oxygenation was signific…

Mass spectrometric identification of the amino donor and acceptor sites in a transglutaminase protein substrate secreted from rat seminal vesicles.

1991

Four different transglutaminase-modified forms of a protein secreted by the rat seminal vesicles (SV-IV) were synthesized in vitro and characterized. FAB maps of both the native protein and its derivatives, produced by the purified guinea pig liver enzyme in the presence or absence of the polyamine spermidine, were obtained by mass spectrometric analysis after proteolytic digestions. Two differently derivatized SV-IV molecular forms, both possessing only one glutamine residue out of two (Gln-86) cross-linked to endogenous lysine residues, were produced when spermidine was omitted from the reaction mixture: (i) an insoluble homopolymer in which Lys-2, -4, -59, -78, -79, and -80 were involved…

Creating a conditional mutation of Wnt-1 by antisense transgenesis provides evidence that Wnt-1 is not essential for spermatogenesis.

1993

We have used mice transgenic for an antisense construct for Wnt-1 to study the role of this gene in post-meiotic sperm development. The human PGK-2 promoter provided levels of Wnt-1 antisense mRNA in testes in 5 transgenic lines greatly in excess of Wnt-1 mRNA concentrations, and Wnt-1 mRNA levels were greatly decreased in the lines, by 98% in three of them. There was a general correlation between copy number of the insert, levels of antisense RNA, and decreases in mRNA. There was little effect of the antisense transgene on fertility or testicular histology suggesting that normal levels of Wnt-1 transcript are not essential for spermatogenesis.

Changes in Serum and Lipoprotein Fatty Acids of Growing Rats Fed Protein-Deficient Diets with Low or Adequate Linolenic Acid Concentrations

1992

The effects of a protein-deficient diet associated with sunflower oil [adequate in 18:2(n-6), poor in 18:3(n-3)] or soybean oil [adequate in both 18:2(n-6) and 18:3(n-3)] on lipid serum and lipoprotein compositions were studied in growing rats. Four groups of rats were fed different diets: SFC (20% casein + 5% sunflower oil); SFd (2% casein + 5% sunflower oil); SC (20% casein + 5% soybean oil); Sd (2% casein + 5% soybean oil). After 28 d, both protein-deficient groups exhibited low concentrations of protein, phospholipid, triacylglycerol and total cholesterol in serum and VLDL. Compared with rats fed 20% casein diets, those fed low protein diets had lower 18:2(n-6) and 20:4(n-6) in phosphol…

?-Carotene Supplements Cannot Meet All Vitamin A Requirements of Vitamin A-Deficient Rats

1993

Effect of refeeding diets containing cottonseed flour with traces of gossypol on rat liver and testis

1991

The aim of the present work was to show that cottonseed flour introduced into rehabilitation diets is not nutritionally harmful. The cottonseed flour obtained from glandless seeds contains traces of gossypol. As gossypol is known to have pathological hepatic and testicular actions, the effects on hepatic variables and on the histological appearance of liver and testis of diets containing cottonseed flour were compared with those without cottonseed flour. Seventy growing male Wistar rats were divided into two groups. The control group (C) received a balanced diet (200 g casein+3 g methionine/kg) for 78 d and the experimental group was fed on a low-protein diet (20 g casein+3 g methionine/kg)…