[The influence of different glycerol concentrations on the conservation of structure of unfixed and fixed boar spermatozoa investigated by freeze-etching (author's transl)].
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Animals↗
Biomedical subjects
E Rovan
Publications and source records attributed to E Rovan.
[The agar-tube method for electron microscopical preparation of cell suspensions and small tissue fragments (author's transl)].
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Agar↗
Effect of gossypol on testicular testosterone production in vitro.
Testicular minces were utilized to study the effect of gossypol on testosterone production. Testosterone production was assessed in both control nd gossypol treated groups after 0 to 4 hours incubation in the presence of hCG. Media testosterone was measured by radioimmunoassay. Gossypol did not alter testosterone production when present in incubates at the concentrations of 3.5 x 10(-5) M, 7 x 10(-5) M and 3.5 x 10(-4) M. Preincubation of testis mince with gossypol (7 x 10(-6) M, 7 x 10(-5) M, 3.5 x 10(-4) M) for 1 to 4 hours did not alter subsequent hCG induced testosterone production in mature rats. Testosterone production however, was inhibited in immature rat testis when the whole testis was incubated for 4 hours with different concentrations of gossypol (7 x 10(-6) M, 7 x 10(-5) M, 3.5 x 10(-4) M). In vivo testosterone production was not inhibited in the immature rat testis 24 hours after oral administration of gossypol (100 mg/kg).
Animals↗
Antifertility efficacy of gossypol acetic acid in male rats.
Fertility response and sperm motility of male Wistar rats exposed to various concentrations (2.5 - 30 mg / kg / day) of gossypol acetic acid (GAA) was studied. GAA was given orally. A marked reduction in fertility occurred when rats received more than 15 mg / kg / day of GAA for 5 - 10 weeks (p less than 0.01); dosage below 15 mg had no antifertility effect even after 20 weeks. There is some evidence that GAA administration (30 mg / kg) every other day for 10 weeks had no antifertility effect. A clear relationship between the inhibition of sperm motility and GAA administration was observed (p less than 0.01). The interrelationships between fertility, sperm motility and GAA treatment were analyzed by Yates' chi-square test and Fisher's exact test.
Animals↗
Toxicity of gossypol at antifertility dosages in male rats: statistical analysis of lethal rates and body weight responses.
The lethal rates and body weight responses of male Wistar rats following oral treatment with gossypol acetic acid (GAA) at dosages of 2.5-30 mg/kg were analysed by various statistical procedures. Daily treatment with GAA for 10 weeks was associated with lethal rates significantly different from placebo groups in both the low dose (2.5, 5.0, and 7.5 mg/kg, p less than 0.05) and high dose groups (15, 20 and 30 mg/kg, p less than 0.01). The pronounced mean body weight gain observed in placebo groups, was suppressed in the GAA-treated groups at each dose level after 10 weeks. This indicates decreased appetite and/or lessened feed utilisation caused by GAA activity. GAA administration at a dose of 30 mg/kg every other day exerted identical deleterious effects as daily treatment. As derived from the antifertility responses of the GAA treatment groups it was evident that the toxic activity of GAA was not related to its antifertility efficacy. It is concluded that GAA has remarkable toxicity at antifertility dosages in rats.
Administration, Oral↗
Bioassay for determination of human serum luteinizing hormone (LH): a routine clinical method.
Serum levels of LH are used as marker of a number of pathological conditions. In the past many methods (RIA, IRMA, ELISA) have been employed to measure serum LH, these procedures, however, suffer from the drawback that they determine the immuno reactive and not the bioactive part of the hormone. An improved in vitro bioassay method for the estimation of serum LH has been described. The underlying mechanism of the assay is testosterone production by mouse Leydig cells in the presence of added LH. The method has been significantly improved in terms of sensitivity (0.2 IU/l) and simplicity; the assay is simple and does not require any special instruments and can be set up in any endocrinological laboratory.
Animals↗
Effect of gossypol on immature male rats.
In immature male rats the body growth rate, the testis and epididymis weight were not affected by gossypol treatment (4, 8 and 40 mg/kg body weight/24 hrs. for 30 days). There was however a marked reduction in the weight of the prostate after high dose gossypol administration. Furthermore gossypol treatment did not show any effect on the histoarchitecture of the testis nor did the drug treatment have any effect on sperm motility. The plasma levels of testosterone, LH and FSH in gossypol treated animals were no different from those on the controls.
Animals↗