Khat (Catha edulis) lowers plasma luteinizing hormone (LH) and testosterone secretion, but increases cortisol levels in male rabbits.

AIM: This study investigated the effects of fresh khat extract on specific circulating hormones in male rabbits. MATERIALS AND METHODS: A total of 25 male New Zealand White rabbits were divided into five groups each comprising five animals. The first four groups were fed four doses (1.5 g/kg, 4.5 g/kg, 13.5 g/kg and 40.5 g/kg body weight) of khat extract twice a week for 5 weeks while the last group, serving as control, was fed only normal saline via intragastric tube. Blood samples were collected at 15 min interval for up to 3 h after khat extract administration and plasma assayed for luteinizing hormone (LH), testosterone and cortisol levels using radioimmunoassay technique. RESULTS: Khat extract at all doses significantly lowered (P<0.05) LH pulse frequency, area under LH curve, mean plasma LH and mean plasma testosterone levels. Plasma cortisol levels were significantly elevated (P<0.05) in khat-treated rabbits in a dose-dependent manner. CONCLUSION: This study demonstrates that khat may impair reproductive function in male rabbits by interfering with sex hormone profiles.

Anti-fertility effects of embelin in female Sprague-Dawley rats may be due to suppression of ovarian function.

Effects of embelin on oestrous cycle, plasma levels of progesterone and oestradiol, and in vitro production of oestradiol and progesterone by mixed ovarian cells was studied. Forty adult (4 months old) regularly cycling female Sprague-Dawley rats were divided into four groups of 10 rats each. Groups I and II (controls) were given 1 ml/kg body weight of physiological saline or corn oil (vehicle). Groups III and IV received 10 mg/kg and 20 mg/kg body weight embelin in corn oil, respectively. Emberlin disrupted the oestrous cycles in Groups III and IV animals, and there was a significant depression in plasma oestradiol (p <0.05) and progesterone (p <0.02) at both 10 and 20 mg/kg body weights, respectively. Isolated mixed ovarian cells from embelin treated rats produced significantly less progesterone and estradiol than controls in vitro. It is concluded that embelin probably interferes with reproductive functions in female rats by suppressing ovarian production of sex steroid hormones.

Progesterone and 5 beta-pregnanediol production by isolated fetal placental binucleate cells from sheep and goats.

Enzymic dispersion and density gradient separation were used for the isolation of enriched populations (60-90%) of cells from the corpus luteum, placenta and peripheral blood of pregnant sheep and goats. Analysis of the steroids produced from radioactive pregnenolone demonstrated that placental binucleate cells can produce progesterone and 5 beta-pregnanediol whereas white blood cells were relatively inactive. Thus, sheep binucleate cells converted pregnenolone predominantly to progesterone as did sheep luteal cells. However, goat binucleate cells produced 5 beta-pregnanediol as the major metabolite, which is consistent with its production in vivo during pregnancy. Production of progesterone (sheep) or 5 beta-pregnanediol (goat) by binucleate cells was shown to be proportional to the number and viability of the cells. In contrast with the binucleate cells there was no evidence that trophectodermal uninucleate cells play a significant role in placental progesterone or 5 beta-pregnanediol synthesis in either species.

The role of trophoblast binucleate cells in implantation in the goat: a quantitative study.

The number of goat trophoblastic binucleate cells, the incidence of their migration and the formation of trinucleate and syncytial cells in the maternal uterine epithelial layer was estimated quantitatively using transmission electron microscopy between 14 and 23 days postcoitum (dpc). Binucleate cells were first observed at 18 dpc and their proportions increased rapidly from less than 1 per cent to 16 per cent by 19 dpc and 22 per cent by 23 dpc. The appearance of trinucleate cells within the maternal uterine epithelial layer coincided with evidence of migration and fusion of binucleate cells with individual uterine epithelial cells, and an increased death rate among the other uninucleate uterine epithelial cells. There was also a slight increase in the incidence of intraepithelial lymphocytes close to the trinucleate cells. The quantitative studies uphold the hypothesis that at implantation in the goat, placental trinucleate cells and their subsequent multinucleate syncytial plaque derivatives are fetomaternal hybrid tissue formed by fusion of a binucleate cell(s) with a single uterine epithelial cell.

Characterization of antigens expressed in normal baboon trophoblast and cross-reactive with HIV/SIV antibodies.

Electron microscopic studies have revealed the presence of endogenous retroviral (ERV) particles in normal primate placental tissues. These particles have ultrastructural similarities to type C retroviral particles and are mainly associated with the trophoblast. In normal human placental tissues, they have antigenic similarity with exogenous retroviruses, such as the human immunodeficiency virus (HIV), and may have a role to play in the regulation of cellular gene expression, syncytiotrophoblast formation or pregnancy-related immunosuppression. In this study, a panel of antibodies (polyclonal and monoclonal antibodies) against viral proteins (anti-HIV and anti-SIV) and endogenous retroviral (ERV) proteins were assessed by immunohistochemistry and immunoblotting, for their cross-reactivity with ERV particles isolated from normal baboon placental tissues. The antibodies (anti-HERV-K RT, anti-ERV3 env, anti-HIV-1 p17, anti-HIV-2 gp120) reacted positively with the syncytiotrophoblast and each antibody recognized one or two proteins of molecular weights (MW) 38, 58 or 64 kDa present in the baboon placental villous tissues and SIV-infected molt-4 Cl8 cells, but not in uninfected cells. The results of this study confirm the specific expression of retroviral cross-reactive antigens in normal baboon placental tissues and suggest placental cellular proteins may have antigenic similarity with those recognized by anti-HIV/SIV antibodies. The role of these retroviral-related proteins expressed at the maternal-fetal interface remain unclear.

Plasma luteinizing hormone levels in response to gonadotropin-releasing hormone agonist and clonidine in Trypanosoma congolense-infected female goats.

Trypanosomiasis, a parasitic disease of humans and animals, occurs over a wide area of Africa and imposes a large socioeconomic burden on the people. In the present study, we investigated whether trypanosomiasis-induced reproductive disorders were due to pituitary or hypothalamic dysfunction by determining plasma luteinizing hormone (LH) response to gonadotropin-releasing hormone (GnRH) agonist or clonidine in Trypanosoma congolense-infected female goats. With GnRH agonist administration, the total amount of LH secreted over a 140-min sampling period on day 23 and day 60 postinfection was consistently higher (71 and 21%, respectively) in infected goats compared to controls. In contrast, clonidine administration to infected goats on day 28 and day 69 postinfection failed to significantly alter the LH pulse frequency or the mean LH pulse amplitude over a 80-min sampling period. The results, especially the lack of response to clonidine, indicate that trypanosomiasis impairs GnRH release from the hypothalamus.

Plasma bioactive LH and testosterone profiles in male New Zealand rabbits experimentally infected with Schistosoma mansoni.

The effects of Schistosoma mansoni (S. mansoni) infection on plasma levels of bioactive luteinising hormone (LH) and testosterone in the New Zealand rabbit model were studied. S. mansoni infection significantly decreased the pulse frequency (P < 0.05), amplitude (P < 0.05), area under LH curve (P < 0.05) and mean plasma LH concentrations (P < 0.05) on days 42 and 70 post-infection, as compared to values for day 14 pre-infection. Areas under the response curves for plasma testosterone levels decreased significantly (P < 0.05) on days 42 and 70 post-infection in infected animals compared to day 14 pre-infection. In the praziquantel-treated group, the levels of LH and testosterone remained unchanged throughout the experimental period. The pulsatile secretion of LH was completely inhibited in S. mansoni-infected animals 70 days post-infection. These results suggest that the effects on reproductive gonadal hormones caused by S. mansoni in the rabbit model may partly be induced by alteration in pituitary synthesis or release of LH.

In vivo and in vitro effects of graded doses of the pesticide heptachlor on female sex steroid hormone production in rats.

Adult female Sprague-Dawley rats were injected with corn oil or 5 mg, 20 mg, 25 mg or 30 mg per kg body weight of heptachlor solution every other day for up to 18 days. The rats were killed at the end of the experimental period, and blood samples were assayed for progesterone and oestrogen by radioimmunoassay. Ovarian cells from the rats were isolated and incubated either on their own, or in the presence of LH or FSH, and production of progesterone and oestrogen determined. Control incubations consisted of cells from corn oil-treated rats. The latter were also incubated on their own or in the presence of LH or FSH. Heptachlor significantly suppressed blood progesterone and oestradiol levels (P < 0.05 to P < 0.001), the degree of suppression depending on the dose and the stage of the oestrous cycle in which samples were obtained. Production of oestradiol by ovarian cells from heptachlor-treated rats was lower than for corn oil-treated controls. Cells from rats treated with low doses of heptachlor (5 mg per kg body weight) showed an increased production of progesterone, while high doses (> 20 mg per kg body weight) suppressed production.

Effects of graded doses of the pesticide heptachlor on body weight, mating success, oestrous cycle, gestation length and litter size in laboratory rats.

Adult female Sprague-Dawley rats were injected with 5 or 20 mg/kg body weight heptachlor solution every other day for up to 18 days. They were weighed every day and the stage of oestrus determined by vaginal smears. One experimental group was mated and pregnancy characteristics studied. Heptachlor affected body weights, cycle patterns, length of gestation period and litter sizes in a dose-related manner. At a dose of 20 mg/kg body weight, heptachlor caused a significant decrease in average body weight (P < 0.01), disrupted and/or prolonged oestrous cycles, decreased mating success (P < 0.001), slightly increased gestation length (P < 0.05) and decreased litter size (P < 0.01).

In vitro production of testosterone and plasma levels of luteinising hormone, testosterone and cortisol in male rats treated with heptachlor.

Male rats were divided into six groups of five rats each. Rats were injected subcutaneously with different concentrations of heptachlor for 2 weeks. Heptachlor at all doses significantly suppressed plasma testosterone levels (P < 0.05). Plasma luteinizing hormone (LH) (P < 0.01) and cortisol (P < 0.02) levels were significantly elevated in heptachlor-treated rats as compared to corn oil-treated controls. LH and testosterone levels showed strong correlation (r = 0.69, P < 0.05). The testes in rats treated with 25 mg/kg body weight of heptachlor showed some pathological changes. We conclude that heptachlor causes adverse effects on several male reproductive parameters in rats.

Morphological characterization of the seminiferous cycle in the goat (Capra hircus): a histological and ultrastructural study.

The cycle of spermatogenesis/seminiferous cycle was investigated in the goat testis using both light and electron microscopy techniques. Using the various cell associations and the accompanying changes in spermatid shape and location, the cycle was divided into eight (8) successive stages. The cycle began with the accomplishment of spermiation (stage 1) and ended with apical migration and close attachment of late maturation phase spermatids at the Sertoli cell apex accompanied by adluminal retention of residual bodies with dense staining inclusions (stage 8). The early stages of the cycle (stages 1-4) were therefore characterized by the presence of only one generation of spermatids, the second one appearing only after the division of secondary spermatocytes in stage 4. Consequently, stages 5-8 had two generations of spermatids; Golgi or cap phase as well as maturation phase spermatids. Although stages 5 to 7 appeared as distinct entities, stages 6 and 7 were rather short-lived and considered as continuations of stage 5. Therefore, the 8 stages of the cycle in the goat were further condensed into 6 main divisions. The duration of each stage was estimated by the frequency of occurrence in sections. Among these, stage 1 had the highest frequency (34%) followed by stages 5-7 (27%). Stages 8 and 4 had the shortest frequency (up to 9%) while stages 2 and 3 had 13% and 12% respectively. These results indicate that, like most domestic species, goats have a cycle of 8 stages with 6 main divisions, the longest being stage 1.

Human endogenous retrovirus-R (ERV 3) env-like antigens expressed in baboon testes and epididymides.

BACKGROUND: A substantial component of the vertebrate genome comprise of retrovirus-related sequences named as endogenous retroviruses (ERVs). The role of these ERV-related sequences in the biological processes of the host species is still unknown. However, they have been associated with tumourigenesis, autoimmune diseases and placental morphogenesis in primates. OBJECTIVE: To determine the expression of ERVs in male baboon reproductive tissues. DESIGN: The testes and other reproductive tissues from sexually immature and mature male olive baboons (Papio anubis) were investigated for the expression of endogenous retrovirus-related particles. Immunohistochemical staining was performed using antibodies raised against human immunodeficiency virus (HIV)-1/2, simian immunodeficiency virus (SIV) and human ERVs. Biochemical properties were determined by western blot, and reverse transcriptase (RTase) activity in epididymal spermatozoa, ejaculate spermatozoa and seminal fluid was evaluated. SETTING: Institute of Primate Research, Nairobi, Kenya. RESULTS: ERV3 env-like antigens were detected on spermatogenic cells in mature baboon testes and on epididymal spermatozoa. Similarly, antigens cross-reactive with antibodies to HIV structural and envelope glycoproteins were expressed in mature and juvenile baboon testes. In addition, reverse transcriptase activity was detected in ejaculate spermatozoa, seminal fluid and epididymal spermatozoa. CONCLUSION: These results indicate that retroviral-related genes were expressed in normal male baboon testes and spermatozoa, similar to humans. The functions of these ERVs in vertebrates remains unclear.

Abortion: behaviour of adolescents in two districts in Kenya.

BACKGROUND: In Kenya the reported high rates of unwanted pregnancies (more than 90%), among adolescents have subsequently resulted in unsafely induced abortions with the associated high morbidity and mortality rates. OBJECTIVE: To evaluate the adolescents' behaviour regarding induced abortion. DESIGN: A cross-sectional, prospective study done from July 1995 to June 1996. SETTING: Schools and health facilities in Kiambu and Nairobi districts in Kenya. PARTICIPANTS: Interviews were conducted among adolescents aged 10-19 years in schools at the two districts and selected using a multi-stage random sampling procedure, as well as adolescent girls at two hospitals and two clinics in the immediate post-abortion period. MAIN OUTCOME MEASURES: The number of adolescents health programmes, aimed at reducing the dangers of unsafely induced abortion, which are designed and subsequently implemented. DATA COLLECTION: Demographic and health data, as well as data on behaviour regarding induced abortion were collected using a self-administered questionnaire. RESULTS: The study sample comprised 1820 adolescents. These were 1048 school girls (SG), 580 school boys (SB) and 192 post-abortion (PA). Many adolescents were aware of abortion dangers, with the awareness being significantly lower among the SB whose girlfriends (GF) had aborted than those whose GF had not (p < 0.01). The practice of abortion was reported among 3.4% SG, 9.3% SBs' GF and 100% PA. Direct and indirect costs of abortion were heavy on the girls. Knowledge of the abortion dangers had no influence on the choice of the abortionist. Abortion encounter positively influenced approval by the adolescents, of abortion for pregnant school girls (p < 0.01). CONCLUSION: Despite the costs and awareness of abortion dangers by adolescents, they will take risks.

Abortion: knowledge and perceptions of adolescents in two districts in Kenya.

BACKGROUND: Pregnancy among adolescents is unplanned in many instances. Although some pregnant adolescents carry the pregnancy to term, abortion, in many instances unsafely induced, is a commonly sought solution in Kenya. OBJECTIVE: To determine adolescents' perceptions of induced abortion. DESIGN: A cross-sectional descriptive study carried out between July 1995 and June 1996. SETTING: An urban and a rural district in Kenya. PARTICIPANTS: Adolescents aged 10-19 years in schools in Nairobi and Kiambu districts, and a group of immediate post-abortion adolescent girls in some health facilities in Nairobi. MAIN OUTCOME MEASURES: The number of health programmes formulated and put into use, which are adolescent-friendly and providing information, education and communication on abortion issues. DATA COLLECTION: One thousand eight hundred and twenty adolescents were subjected to a self-administered questionnaire that collected demographic and health data as well as perceptions of induced abortion. Focus group discussions on perceptions of abortion were held with 12 groups of adolescents in schools and the information obtained recorded on paper and in a tape-recorder. RESULTS: One thousand nine hundred and fifty two adolescents, comprising of 1048 school girls (SG), 580 boys (SB), 192 post-abortion girls (PA) and 132 adolescents in the focus group discussions, formed the study sample. More than 90% were aware of induced abortion (IA). Knowledge of IA correlated positively with level of education (P < 0.01). Seventy one per cent of SG, 84% of PA and 40% of SB were aware of abortion-related complications, the most common being infections, death and infertility. Eighty three per cent of PA felt that complications were preventable by seeking care from a qualified doctor compared to one quarter each for the SB and SG. 56% PA, 69% SB and 72% SG felt that abortions were preventable. However, less than 40% proposed abstinence as a primary strategy. The most important source of information on abortion was the media followed by friends and teachers. CONCLUSION: Adolescents are aware of abortion and the related complications, but there is more variability in their knowledge and preventive measures.

Testicular morphology and testosterone levels in dogs immunized with antibodies generated against an androgen binding antigen in the epididymal cauda.

Adult dogs (Alsatian crosses) were passively immunised intrascrotally or intramuscularly with antibodies generated against an epididymal cauda androgen binding antigen (CABA) for 10 days. The testes were examined histologically 10 or 30 days posttreatment. Testosterone levels were determined on blood obtained daily for 10 days before, during and after treatment. A dose-dependent exfoliation of sperm, spermatids and spermatocytes, in that order, was observed in immunised animals. This was concomitant with the ballooning of luminal ends of Sertoli cells. The effects were, however, reversible. The Leydig cells were not affected by the treatments and plasma testosterone levels before, during and after treatment remained unchanged. It is concluded that an antigen similar to CABA is present in the testis, the neutralisation of which causes testicular lesions without interfering with testosterone levels.

Effects of 6-hydroxydopamine on testosterone production by mouse leydig cells in vitro.

Increasing doses (15 to 1000 micrograms/ml) of 6-hydroxydopamine (6-OHDA) stimulated, then suppressed testosterone production by mouse leydig cells incubated for 3 h in vitro. The stimulating doses ranged between 50 and 100 micrograms/ml, with maximal effects occurring at 30 to 60 minutes after the start of the treatments. At doses of 500 micrograms/ml, 6-OHDA exhibited inhibitory effects. When added to leydig cell incubations together with stimulating doses of luteinising hormone (LH), 1-(3',4'-dihydroxyphenil)2-isopropylaminoethanol (L-isoproterenol) or 8-bromoadenosine 3':5'-cyclic monophosphate (8-Br-cAMP), 6-OHDA abolished the effects of the latter compounds. Prolactin and prostaglandin E2 (PGE2) inhibited the stimulating effects of 8-Br-cAMP but not LH. It is proposed that the actions of 8-OHDA affect intracellular sites yet to be identified, thereby inhibiting testosterone production by mouse Leydig cells. Some of the actions of 6-OHDA seem to be medicated via beta-adrenergic receptors as the latter abolishes the stimulatory effects of L-isoproterenol, a potent beta-adrenergic agonist. However, the inability of stimulatory doses of LH and 8-Br-cAMP to reverse the inhibitory effects of 6-OHDA point to the possibility that other actions of 6-OHDA may be relayed via a second messenger system separate from that involving cAMP.

The role of trophoblastic binucleate cells in implantation in the goat: a morphological study.

In the goat conceptus individual intra-epithelial trophectodermal binucleate cells first appear 18 days post coitum and their incidence rapidly increases where the trophectoderm is apposed to the caruncular and intercaruncular sites of initial attachment to the uterine epithelium. Special staining techniques reveal that these cells, when mature, contain prominent Golgi bodies and numerous characteristic granules. Our evidence shows that at 19 days post coitum the binucleate cells migrate to the microvillar junction and fuse with individual uterine epithelial cells to form hybrid feto-maternal trinucleate cells. It is proposed that subsequent continued binucleate cell migration and fusion with trinucleate cells produce the syncytial plaques typical of the remainder of pregnancy. It is further suggested that the fusion is important in facilitating the delivery of the characteristic granules to the base of the uterine epithelial layer with subsequent exocytosis of their contents into maternal tissue.

Regulation of steroid synthesis and metabolism in isolated binucleate cells of the placenta in sheep and goats.

Binucleate cells of sheep and goat fetal placentae comprise about one-fifth of the trophectodermal layer at the feto-maternal interface. When isolated and incubated in vitro they produce the steroids that are synthesized by the placenta in vivo (progesterone in sheep, 5 beta-pregnane-3 alpha,20 alpha diol in goats). This study demonstrates that progesterone synthesis in binucleate cell preparations in sheep was increased by prostaglandin (PG) E-2, nordihydroguaiaracetic acid (NDGA) and methylisobutylxanthine, but reduced by indomethacin, whereas in goats only NDGA produced any effect (an increase). None of the other compounds tested (luteinizing hormone, follicle stimulating hormone, prolactin, dibutyryl cAMP, A23187 or phorbolmyristic acetate) had any effect. Sheep binucleate cells also produced PGE-2 from arachidonic acid. These results suggest that, in sheep, products of both the cyclooxygenase (producing PGE-2) and lipoxygenase (inhibited by NDGA) pathways of arachidonic acid metabolism have regulatory roles in placental steroid synthesis, but only the lipoxygenase pathway is relevant in goats.

Epididymal epithelial cell involution following a single intraperitoneal administration of ethane dimethanesulfonate in the goat (Capra hircus).

Ethane dimethanesulfonate (EDS) selectively destroys Leydig cells in rats and a few other smaller animal species but not in mice and quail. In the teleost fish, it stimulates testicular activity instead. It also causes formation of sperm granulomas, reduction of sperm fertilizing ability, and destruction of clear cells in the epididymis. Investigations involving larger animal species are scanty. We have previously reported that EDS has no effect on goat Leydig cells but appears to have a direct cytotoxic effect on the seminiferous epithelium. This study was therefore designed to investigate the effects of EDS on goat epididymal cytoarchitecture. EDS was administered intraperitoneally at two dose levels, 75 and 25 mg/kg body wt. The former dose was rather toxic, killing three of five goats in this group within 24 h whereas the latter dose was well tolerated. Six days after treatment, the goats were hemicastrated and the epididymis was isolated and processed for light and electron microscopy. Involution associated with EDS was observed in epithelial cells of all regions of the epididymis, each having its own specific and peculiar changes. In the caput, there was increased cytoplasmic density accompanied by enlarged vacuoles and paucity of secretory vesicles in the apical cytoplasm. The Golgi cisternae were dilated and disorganized and, in the basal aspect, large dense staining bodies or inclusions, degenerative mitochondria, and lamellated bodies were observed. In the corpus, large vacuoles containing flocculent materials occurred in the entire cell cytoplasm but were particularly numerous and large in the midcytoplasm, completely obliterating the Golgi area. There was a dramatic reduction in epithelial height in the cauda epididymis accompanied by sparse distribution of markedly shortened microvilli. The epithelial cells had extensively lobulated nuclei and disorganized cytoplasm with dilated Golgi apparatus and large conglomerations of tubular structures. These structural changes suggest that EDS causes degeneration of goat epididymal epithelial cells. These effects are likely to result from the direct action of the compound on the epithelium.

Partial purification of a putative membrane bound androgen binding protein in the dog cauda epididymis.

1. An androgen binding protein(s) has been partially purified from cell plasma membranes of dog epididymides. 2. The protein(s) has a pI of 5.3 and an association constant of (1.13 x 10(9) M-1). 3. Conclusive demonstration of androgen receptors in epididymal plasma membranes would be of significance in understanding epididymal physiology.