Studies on semen from rabbits injected with H 3 -thymidine and treated with prostaglandins E 2 and F 2

Inhibition of Gonadotropin and Prostaglandin Stimulation of Testicular Steroidogenesis in Malnourished Rats

The effect of human chorionic gonadotropin (hCG) and prostaglandin E1 (PGE1) on testicular steroidogenesis in protein-deficient and refed rats was studied in vitro. The malnourished, refed, and control rats were found to secret testosterone in response to hCG and PGE1 stimulation. There was a significant reduction in the basal level of secretion in the malnourished rat testis (1.0 +/- 0.4 nMol/3 hr./Testis). Malnourished rats refed with adequate protein diet responded to hCG and PGE1 stimulation in a similar manner to normally-fed adult rats.

Influence of prostaglandin F2 alpha on sperm production and seminal characteristics of the stallion

Six mature stallions were used to test the effect of prostaglandin F2 alpha (PGF2 alpha ) on sperm production and seminal characteristics. Semen was collected from each stallion twice weekly 1 hr following a 10 mg intramuscular injection of PGF2 alpha or a sham injection. A switchback design was used so that three stallions received PGF2 alpha and three served as controls during the first 9 weeks (period 1). Treatment regimens were reversed during the second 9 weeks (period 2). Treatment of stallions with PGF2 alpha resulted in an increase (P less than .05) in gel free seminal volume and a decrease in sperm cell concentration. Total spermatozoa, sperm cell motility, and percentage of primary and secondary sperm abnormalities of ejaculates were not significantly affected by treatment of stallions with PGF2 alpha before semen collection. All treated stallions exhibited a pronounced sweating response to the drug. During the experiment, two of the six stallions masturbated within 20 to 30 minutes after PGF2 alpha treatment without achieving an erection.

Prostaglandin E1 and E2 in bovine semen: quantification by gas chromatography

Prostaglandins PGE1 and PGE2 extracted from bovine semen, purified via silicic column chromatography were quantified by gas chromatography as their methoxime methyl ester trimethylsilyl ether derivatives. The PGE2 and PGE2 concentrations of 19 bovine semen samples ranged from 395 +/- 225 and 487 +/- 407 ng/ml, respectively. A constant 1:1 ratio between PGE1 and PGE2 was observed. There was not relationship between PGE and sperm motility, but high sperm counts were generally associated with decreased PGE levels. The direct precursors of PGE1 and PGE2, i.e. 20:3n6 and 20:4n6, occurred in low concentrations compared to other related unsaturated fatty acids, i.e. 18:2n6 and 22:5n6 of the n-6 family.

Effect of chronic treatment with prostaglandin E2 on male rat fertility

Adult male rats were treated with prostaglandin E2 (100 microgram/100 g body wt) during 60 days. Neither morphological alterations in genital organs nor modification in epididymal contractility were observed. Nevertheless, a significant diminution of fertility was registered. This was recovered after 30 days following the cessation of treatment. Since sperm maturation occurs in the epididymis, it is postulated that the decrease of fertility in our experiments was due to an incomplete maturation of germinal cells, induced by a reduction in the time taken by spermatozoa in passing through the duct.

The effects of prostaglandin F2alpha on sperm output in boars

The effect of prostaglandin F2alpha (PGF2alpha) on the sperm output of six boars was investigated in two studies. Although PGF2alpha did not significantly affect sperm numbers in the ejaculate, a significantly longer (P less than 0.05) ejaculation of the sperm rich fraction occurred following injection of PGF2alpha. In the second study it was found that PGF2alpha produced a 49% increase (P less than 0.05) in the number of sperm in the sperm rich fraction of the ejaculate. The implications of these results on artificial breeding are discussed.

Effects of prostaglandins E-1 and F-2ALPHA on serum luteinizing hormone concentration and on some sexual functions in male rabbits

PGE-1(50 mu-g/animal) and PGF-2ALPHA (250 mu-g/animal) caused a transient increase in serum LH at 5 min after injection. PGE-1(250 mu-g/animal) had a biphasic effect on serum LH. A small peak was obtained at 5 min, and a second, larger peak at 60 min after injection. It is suggested that the first peak is a result of the stress associated with injection of the PGs, whereas the second peak represents a physiological effect of PGE. Subcutaneous injection of PGE-1(1 mg in arachis oil b.i.d.) for 10 days did not effect the concentration of LH in serum, the function of the accessory sexual glands or the sexual activity. PGF-2ALPHA, given at the same dose and in the same manner, increased the sexual activity but left all other variables unaffected. The pituitary responsiveness to LH-RH was unaltered by the treatment with PGE-1 and PGF-2ALPHA.

Effect of castration, testosterone treatment and hereditary sterility on prostaglandin concentration in the male reproductive system of mice

The concentration of prostaglandins E and F in different parts of the male reproductive system of CD-1 and dwarf mice was measured by radioimmunoassay. In intact CD-1 mice, the vas deferens contained a significantly higher concentration of PGE and PGF than was found in the epididymis and in the seminal vesicles. All tissues studied had more PGE than PGF. Castration resulted in increased PG concentrations in both the epididymis and the seminal vesicles and decreased PG concentrations in the vas deferens. There was also a differential response of PGE and PGF in the epididymis of genetically sterile dwarf mice (dw/dw) were significantly higher than those observed in their normal littermates ((PLUS)). A reversed PGE/PGF ratio was found in the mates. The results indicate that testicular androgens affect the levels of PGE and PGF in the reproductive system of male mice. The physiological role of PGs in male reproductive functions has not been established, but there is a suggestion that PH have a role in controlling the transit of spermatozoa through the epididymis and vas deferens.