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.

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.

Effect of menstrual cycle on mucosal immunity to SHIV within the reproductive tract of baboons (Papio anubis): preliminary findings.

The presence of human immunodeficiency virus (HIV) in genital secretions is regarded as a risk factor for sexual and perinatal transmission of HIV. A better understanding of correlates of genital shedding of HIV is crucial to the development of effective strategies against transmission of this virus. Events during menstrual cycle are likely to influence local immune responses and viral load in genital secretions, and hence determine susceptibility to HIV or efficiency of virus transmission. We report, in this study, preliminary findings on the relationship of menstrual cycle to genital mucosal and systemic immunity in female olive baboons (Papio anubis) experimentally inoculated with simian/human immunodeficiency virus (SHIV)89.6P.

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.

Progesterone; Estradiol and their Receptors in Leiomyomata and the Adjacent Normal Myometria of black Kenyan Women

The contents of progesterone and oestrogen; and their respective receptors in uterine leiomyomata and adjacent normal myometrial tissue in indigenous black women in Kenya were studied. A random selection of twenty women undergoing hysterectomy for uterine fibroids at Kenyatta National Hospital was used for the studies. The myometria contained higher levels of E(2 ) (181: P 0.001); and P(4 ) (240.6: P 0.001); as compared to the leiomyomata. On the other hand uterine leiomyomata contained significantly higher levels of ER (147.6: P 0.001); and PR (178.7: P 0.001 ); than normal myometria. These findings differ slightly from those reported in black women in developed countries; but support the proposal that manipulation of sex steroids may be useful in the treatment and management of uterine leiomyomata

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.

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.

Purification and partial characterisation of goat placental IgG: A possible model for the study of human maternal-foetal interaction.

Viviparous pregnancy in vertebrates is a major immunological puzzle. Ideally the maternal immune system should reject the foetus, which is antigenically different by virtue of its compliment of paternal genes and proteins. Instead the mother accommodates the foetus until term. This is partly thought to result from production of blocking antibodies, down regulation of the maternal immune responses and existence of a placental barrier among others. This report presents findings that antibodiess exist on goat placentae that could hypothetically block rejection of the fetal allograft. The total obtainable placental IgG was approximately 110Ug per term placenta. Analysis of eluate antibodies by SDS PAGE showed that placental IgG is approximately 214.4kDa and had a pI of 6.02. Trypsin digestion of acidified plantal microvesicles led to release of a 53kDa peptide similar to one reported earlier in humans. This observation suggest that certain placental proteins may be conserved across the mammalian species for reproductive purposes. We propose that goat placental IgG may be useful as a model for the study of maternal-foetal interaction during pregnancy.

Purification and Partial Characterization of Goat Placenta IgG : a Possible Model for the Study of Human Maternal-Foetal Interaction

Viviparous pregnancy in vertebrates is a major immunological puzzle. Ideally the maternal immune system should reject the foetus; which is antigenically different by virtue of its compliment of paternal genes and proteins. Instead the mother accommodates the foetus until term. This is partly thought to result from production of blocking antibodies; down regulation of the maternal immune responses and existence of a placental barrier among others. This report presents findings that antibodiess exist on goat placentae that could hypothetically block rejection of the fetal allograft. The total obtainable placental IgG was approximately 110Ug per term placenta. Analysis of eluate antibodies by SDS PAGE showed that placental IgG is approximately 214.4kDa and had a pI of 6.02. Trypsin digestion of acidified plantal microvesicles led to release of a 53kDa peptide similar to one reported earlier in humans. This observation suggest that certain placental proteins may be conserved across the mammalian species for reproductive purposes. We propose that goat placental IgG may be useful as a model for the study of maternal-foetal interaction during pregnancy

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.

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.

Immunohistochemical localization of retroviral-related antigens expressed in normal baboon placental villous tissue.

Endogenous retroviral particles (ERVs) have been detected in the genome of all eukaryotes. They are generally non-pathogenic except in mice where they have been found to induce tumors and immunological disorders. The ERVs have morphological features consistent with type-C retroviral particles and are commonly expressed in normal placental villous tissues. ERVs may have a role in the regulation of placental gene expression, syncytiotrophoblast formation, or pregnancy-related immunosuppression. In this study, well-characterized antibodies (monoclonal and polyclonal antibodies) raised against retroviral proteins (anti-HIV and anti-SIV) and endogenous retroviral (ERV) particles were assessed for their cross-reactivity (by using immunohistochemistry) with normal baboon placental and other adult tissues. The monoclonal antibodies to exogenous retroviral proteins (anti-HIV-2 gp120, anti-HIV-1 gp41, anti-SIVmac p27, anti-HIV-1 RT, and anti-HIV-2 core protein) showed specific immunohistochemical reactivity with the syncytiotrophoblast. Antibodies to endogenous retroviral gene products (anti-ERV3 env, anti-HERV-K RT, and anti-HERV-K env) also reacted in a similar manner and did not cross-react with other adult tissues. These studies have shown that retroviral-cross-reactive proteins are expressed in baboon placental syncytiotrophoblast and may have a role to play at the feto-maternal interface.

Characterisation of retroviral-related antigens expressed in normal baboon placental tissues.

The genomes of all eukaryotes contain multiple copies of DNA sequences that are related to sequences found in infectious retroviruses. Endogenous retroviruses (ERVs) are generally non-pathogenic although they have been implicated in the induction of tumours and immunological disorders. The ERVs have morphological features consistent with type-C retroviral particles and are expressed in normal placental tissue in most mammals. They have antigenic similarity with exogenous retroviruses such as HIV-1 and may have a role to play in the regulation of cellular gene expression, syncytiotrophoblast formation or pregnancy-related immunosuppression. Some of the human endogenous retroviruses have been well-characterised. Among the non-human primates, the baboon endogenous virus (BaEV) is the only endogenous retrovirus so far which has been shown to be effective in vitro. The entire nucleotide sequence of BaEV has been determined. It has been shown to have a chimeric genomic structure of about 8 kb long. BaEV particle expression in placental tissues has been demonstrated using electron microscopy. However, to date, very little work has been done to evaluate the expression of retroviral-related antigens in normal baboon tissues. In this study, mouse polyclonal antibodies were produced against isolated baboon placental ERV particles and characterised using immunohistochemistry and immunoblotting techniques. Most of the anti-BERV antibodies displayed specific immunoperoxidase staining on placental syncytiotrophoblast and cross-reacted with exogenous retroviral proteins on immunoblot analyses. Reverse transcriptase (RTase) activity associated with sucrose gradient-purified placental retroviral-like particles were also demonstrated. These studies indicate that endogenous retroviral particles are expressed in baboon placental villous tissue and suggest retroviral proteins may play an immunomodulatory role at the maternal-foetal interface.

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.

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.

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).