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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.

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Heptachlor, a chlorinated hydrocarbon pesticide, suppresses the production of progesterone and estradiol in the female rat in vivo or in isolated ovaries in vitro. In this study the effect of heptachlor on steroid hormone production by isolated rat luteal and follicular cells, in the presence of two precursor hormones was investigated. Ovaries were isolated from anesthetized mature normocyclic virgin rats (3 to 4 months old), under sterile conditions. Corpora lutea and follicles were microscopically dissected out and separately enzymatically dispersed with collagenase at 37 degrees C. Viable cells collected after centrifugation were used at a concentration of approximately 2.5 x 10(5) cells/10 mL. Both luteal and follicular cell preparations were separately incubated overnight (15 h) at 37 degrees C in the presence of pregnenolone (P5) and androstenedione (A4) at a concentration of 6.0 nmol/L each, and heptachlor at either 0.12 microg/mL (low dose) or 1.20 microg/mL (high dose) (test cells) or in the absence of heptachlor (control cells). At the end of the incubations, progesterone and estradiol 17beta levels were analyzed in the incubation media. The results indicate that heptachlor significantly suppressed the production of both progesterone and estradiol in both cell types in a dose related manner even in the presence of A4 and P5 as precursor hormones (P<0.05).

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Acetophenone and veratrole have been identified as two major behaviourally active components of the oviposition aggregation pheromone of the desert locust, Schistocerca gregaria. These compounds were identified from the volatiles of egg pod froth using gas chromatography-electroantennographic (GC-EAD) and gas chromatography-mass spectrometric (GC-MS) analysis. Both compounds were shown to elicit aggregation of gravid females in oviposition bioassays; however, they do not act synergistically. Both acetophenone and veratrole individually at optimum doses induced about 70% egg laying, a value similar to that evoked with froth volatiles.

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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.

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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.

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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.

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A total of 257 boys (age range 4-55 months), who had acute diarrhoea with moderate to severe dehydration, were randomly assigned to treatment with either the World Health Organisation/United Nations Childrens Fund (WHO/Unicef) recommended oral rehydration solution or cereal based oral rehydration solution made either of maize, millet, sorghum, or rice. After the initial rehydration was achieved patients were offered traditional weaning foods. Treatment with oral rehydration solution continued until diarrhoea stopped. Accurate intake and output was maintained throughout the study period. Efficacy of the treatment was compared between the different treatment groups in terms of intake of the solution, stool output, duration of diarrhoea after admission, and weight gain after 24, 48, and 72 hours, and after resolution of diarrhoea. Results suggest that all the cereal based solutions were as effective as glucose based standard oral rehydration solution in the treatment of diarrhoea.

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