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W Lietz

Publications and source records attributed to W Lietz.

17 recordsLinked to original sources
PubMed1987

[Effect of cholesterol on the level of ascorbic acid in the plasma and tissues of rabbits].

Studies were carried out on 10 rabbits divided into two groups. Group I was fed on a physiological diet, group II was given additionally 200 mg of cholesterol daily. After 2 weeks the rabbits were decapitated and, having prepared the tissues according to Zannoni, the level of vitamin C was determined in the plasma, liver and intestinal wall by the method of Roe-Kuenther. It was shown that the diet rich in cholesterol caused a decrease in the level of vitamin C in the organism. The level of ascorbic acid decreased by 57% in the liver and plasms, by 52% in the wall of the caecum, whereas by 30% in the wall of the jejunum. A high level of cholesterol in the organism seems to increase its demand for vitamin C.

Animals↗
PubMed1987

Evaluation of mare oocyte collection methods and stallion sperm penetration of zona-free hamster ova.

Comparisons were made between 2 methods of oocyte recovery from the ovarian follicles of slaughtered mares: 500 oocytes (3 per mare) were obtained by aspiration of follicular fluid from ovaries of 162 mares, and 120 oocytes (8 per mare) by isolation and rupture of follicles from ovaries of 14 mares. In the oocytes recovered after rupture of follicles, 89.2% were morphologically unchanged, in comparison to 29.3% obtained by aspiration of follicular fluid. Stallion spermatozoa capacitated in vitro were tested on zona-free hamster oocytes. The stallion spermatozoa were washed in TCM-199 and preincubated for 4-5 h at a concentration of 0.5-1.0 x 10(9)/ml. Of the 305 hamster oocytes fertilized by spermatozoa obtained from 8 stallions, 77.8% penetration was confirmed on the basis of the presence of enlarged heads of spermatozoa and male pronuclei with their corresponding tails. Spermatozoa from one of the stallions were tested 10 times, 8 months later. The percentage of penetrated oocytes averaged 52.8% (39.1-76.9%). In the control group of oocytes preincubated in the absence of spermatozoa, spontaneous activation and female pronuclei were found in 12 out of a total of 57.

Animals↗