K. T. Kirton

Sperm capacitation by uterine fluid or beta-amylase in vitro.

Rabbit sperm developed the capacity to fertilize ova when incubated in utero or in vitro in fluids from estrous uteri. Incubation of sperm with beta-amylase in phosphate-buffered Lockes solution also resulted in capacitation. The data suggest that sperm capacitation involves enzymatic alteration of carbo-hydrate-containing seminal macromolecules which coat sperm and inhibit fertilization.

Anterior Pituitary Levels of FSH, LH, ACTH and Prolactin After Mating in Female Rabbits.

Summary Anterior pituitary levels of LH, FSH, ACTH and prolactin were determined at 0, 0.25, 0.75, 3, 7, or 11 hours after mating in 96 female rabbits. Levels of LH, ACTH and prolactin decreased rapidly after mating to low levels which persisted from 0.75 to 7 hours after mating, but copulatory levels of these tropins were largely restored within 11 hours after mating. Pituitary FSH was not significantly influenced by copulation. The results indicate that the mating stimulus is not specific for ovulating hormone release and suggest that other pituitary tropins may affect reproductive function near the time of ovulation.

Seminal Composition and Sexual Activity after Castration and Testosterone Replacement in Rabbits

Summary Losses of libido and seminal volume, fructose and gel were quantified in eight rabbits ejaculated every second day for 26 days after castration. Androgen requirement for restoration of normal libido and seminal characteristics was established in the same rabbits by injections of testosterone propionate (TP) at levels of from 0.5 to 12.0 mg every second day. Gel mass disappeared from ejacula immediately after castration and seminal fructose declined from 760 μg before castration to 192 μg/ejaculum within 48 hr. But seminal volume and libido declined only gradually and linearly for 3 weeks after castration. Even after 26 days, nearly all rabbits mounted and thrust vigorously although unable to ejaculate. Although libido of castrate rabbits was increased significantly by 0.5 or 1.0 mg of TP, seminal characteristics were not. Control levels of both were reestablished at 8.0 mg of TP.

RETURN OF OVULATORY CYCLICITY FOLLOWING AN INTRAMUSCULAR INJECTION OF MEDROXYPROGESTERONE ACETATE (PROVERA

In order to determine the relationship between peripheral serum concentrations of medroxyprogesterone acetate (Provera) and progesterone following an intramuscular injection of 150 mg of depo-medroxyprogesterone acetate nonpregnant nonlactating healthy women between ages 19 and 35 and with a history of regular menstrual cycles and no history of pregnancy or use of oral contraceptives or other hormone therapy within the previous 3 months were selected for study. Following the injections at 5-20 days post-injection concentrations ranged from 10-25 ng/ml and then decreased to 5-10 ng/ml by 30 days post-injection. The concentration decreased gradually with little change during the remainder of the study. 1 exception was the increased concentration found at 63 and 70 days post-injecton in a subject. The minimal detectable concentration of medroxyprogenterone acetate was 0.5 ng/ml. All samples were above this level in all 3 subjects prior to 185 days post-injection. In 1 of the 3 patients levels were below this amount in some of the samples between days 185 and 228 but detectable levels were present in all 3 subjects wihtin 30 days of the initial progesterone increase. The study shows that 150 mg of intramuscularly administered medroxyprogesterone acetate (Provera) can suppress ovulation for 200 days.

SPERM CAPACITATION BY UTERINE FLUID OR BETA-AMYLASE IN VITRO

Rabbit sperm developed the capacity to fertilize ova when incubated in utero or in vitro in fluids from estrous uteri. Incubation of sperm with beta-amylase in phosphate-buffered Lockes solution also resulted in capacitation. The data suggest that sperm capacitation involves enzymatic alteration of carbo-hydrate-containing seminal macromolecules which coat sperm and inhibit fertilization.