Binding of monoclonal antibody MHS-5 to western blots of human seminal plasma was employed to follow the fate of a seminal vesicle-specific antigen (SVSA) during semen liquefaction. Ejaculates from four vasectomized donors were collected in a manner to inhibit liquefaction or to allow liquefaction to proceed at room temperature. Aliquots of the liquefying seminal fluid were removed at specific time points and further liquefaction inhibited with sodium dodecyl sulfate (SDS). Western blot analysis using monoclonal antibody MHS-5 demonstrated that the SVSA epitope in all donors was located on multiple bands ranging in mass from 15-92 kDa in unliquefied ejaculates; immunoreactive peptides below 15 kDa were not detected. As early as 5 min post ejaculation, immunoreactive bands below 15 kDa were identified in liquefying samples. During the same time period (5 min), immunoreactive bands of 69-71 and 58 kDa could not be immunologically detected in liquefying samples. A decrease in immunoreactive staining of components higher molecular mass was accompanied by a concomitant increase in immunoreactive staining of intermediate and small molecular mass molecules during the first 2 h of liquefaction. After 8-24 h of liquefaction, two immunoreactive bands of 10.9 and 12.5 kDa predominated. Between 24 and 48 h, each donor's ejaculate demonstrated a common single immunoreactive band of 10.9 kDa. These results indicate that there is a rapid transformation in mass of the SVSA with major 69-71 and 58 kDa bands being converted to forms of lower mass within 5 min of ejaculation.
Crosses of BALB/c female mice and inbred wild male mice (PWD, PWK) produce fertile female progeny, but the male offspring are sterile. The hybrid male sterility is a direct action of the hybrid sterility genes Hst-1s and Hstws. Previous reports concluded that spermatogenic arrest effected the sterility. However, the testicular steroidogenesis of hybrid sterile male mice has not been elucidated. In the present report, the steroidogenic capacity of hybrid sterile and parental strain males was directly assessed by quantifying testosterone secretion by maximally stimulated testes perfused in vitro. Additionally, Leydig cell mass and germ cell volumes were morphometrically determined. The experimental results confirm the deleterious impact of the Hst-1s/Hstws genotype on spermatogenesis and demonstrate for the first time that the steroidogenic capacity of hybrid sterile testes is reduced. The biochemical defects that cause the impairment of testicular function are unknown.
Previous studies show that hysterectomy on Day 1 of pseudopregnancy prolongs serum progesterone secretion in estrogen-treated pseudopregnant rabbits. These studies were undertaken to determine the day of pseudopregnancy when uterine factors are released to alter luteal function. When hysterectomies were performed on either Day 5, 8, 10, or 13 of pseudopregnancy, serum progesterone concentrations were greater than 10 ng/ml between Days 18 and 27 of pseudopregnancy compared to levels of approximately 4 ng/ml in sham-hysterectomized rabbits on these same days. In contrast, serum progesterone levels were not elevated when hysterectomies were performed on Day 11 of pseudopregnancy and were only partially maintained when hysterectomies were performed on Day 12 of pseudopregnancy. Twice daily injections of prolactin (1.5 mg, s.c.) between Days 1 and 33 of pseudopregnancy were unable to mimic the effect of estradiol in the hysterectomized rabbit. Twice daily injections of indomethacin (8 mg/kg, s.c.) between Days 6 and 23 of pseudopregnancy lowered uterine and luteal prostaglandin F2 alpha levels approximately 10-fold on Day 24 of pseudopregnancy but did not maintain progesterone secretion. Serum cholesterol levels were not altered by hysterectomy on any day and were thus not related to the maintenance of progesterone production. These results suggest that the uterus produces both inhibitory and stimulatory factors that effect luteal progesterone secretion. First, an inhibitor is released between Days 10 and 11 of pseudopregnancy in estrogen-treated rabbits that prevents the rabbit corpus luteum from responding to estradiol.
Uterine proteins secreted in response to estrogen and modulated by progesterone have previously been demonstrated in the immature rat. An in vitro radiolabeling technique with 35S-methionine was used to culture uteri from animals in estrus, pregnancy and the post partum period. Proteins released into the media (media proteins) were analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. On Days 1 and 2 of pregnancy, a 115,000 M.W.protein similar in molecular weight to one previously described by this laboratoryis prominent. Its disappearance by Day 3 coincides with increased progesterone secretion. The appearance of a 43,000 M.W. protein is the most marked change at the time of blastocyst invasion of the uterine epithelium. A new 160,000 M.W. protein begins to emerge on Day 5 and is prominent in later gestation. The latter protein is thought to be a product of the uterine decidua. Its production in ovariectomized animals is increased in the presence of progesterone and a nonspecific decidual stimulus. In the immediate post partum period, a 115,000 M.W. protein reemerges, and the 160,000 M.W. protein disappears. It is believed that these proteins are influenced by the hormonal events of pregnancy and may represent an expression of the genetic control of gestation.