In the structure of brain the medial preoptic area (MPO) and ventromedial nucleus of hypothalamus (VMN)are the two parts where the estrogen receptors concentrate but have opposite effects on sexual behavior. Recently ...In the structure of brain the medial preoptic area (MPO) and ventromedial nucleus of hypothalamus (VMN)are the two parts where the estrogen receptors concentrate but have opposite effects on sexual behavior. Recently estrogen receptors have been known to be located in the locus coeruleus(LC), where noradrenergic(NE) fibres terminate in the hypothalamus arising from cell bodies. The discharge rate of NE-ergic neurons in LC can be increased by electrical stimulation of MPO in a female rat at estrus stage, and decreased at diestrus stage. These studies help us to infer that VMN might have some modulation influence on NE-ergic neurons in LC. In order to study the pattern activities展开更多
Several studies showed that sex hormone receptors are in close relationship with classical neurotransmitter neurons especially catecholaminergic(CA) neurons. There are many gonadotrophin releasing hormone (GnRH) neuro...Several studies showed that sex hormone receptors are in close relationship with classical neurotransmitter neurons especially catecholaminergic(CA) neurons. There are many gonadotrophin releasing hormone (GnRH) neurons in hypothalamus and the medial preoptic area (MPO). Electrical stimulation of MPO can cause a rise in secretion展开更多
Objective: To investigate the effect of different fractions from the aqueous methanolic root bark of Adansonia digitata (Linn) on the estrous cycle of female Wistar rats and to elucidate their phytochemical content. M...Objective: To investigate the effect of different fractions from the aqueous methanolic root bark of Adansonia digitata (Linn) on the estrous cycle of female Wistar rats and to elucidate their phytochemical content. Methods: Crude aqueous methanol extract of Adansonia digitata (Linn) root bark was fractionated by column chromatography using various ratios of hexane, acetyl acetate, methanol and distilled water. Fractions with similar trails on a thin layer chromatography were pooled into four fractions. Each fraction was then screened for its phytochemical content. Forty mature Wistar female rats weighing (135±28) g with regular estrous cycles were given each fraction at two dose levels while a control group received distilled water of equal volume. Treatments were given per os for 15 days starting from the day of estrus. Vaginal smears were observed daily for the duration of each cycle, frequency of occurrence of each stage of the estrous cycle and number of cycles for 15 days before and during treatment. At the end of treatment, rats were humanely sacrificed. Ovaries and uteri were weighed and processed for histopathology. Results: Hexane acetyl acetate and acetyl acetate methanol fractions at 150 mg/kg body weight and 300 mg/kg body weight prolonged the occurrence of proestrus and diestrus and produced atretic cyst-like ovaries at 300 mg/kg body weight. Acetyl acetate methanol treated rats also had low relative ovarian weights when compared to the control. Conclusions: Sterols and triterpenes in hexane acetyl acetate and acetyl acetate methanol fractions of the root bark may be responsible for the disruption of estrous cycle in female Wistar rats and may have a contraceptive effect.展开更多
文摘In the structure of brain the medial preoptic area (MPO) and ventromedial nucleus of hypothalamus (VMN)are the two parts where the estrogen receptors concentrate but have opposite effects on sexual behavior. Recently estrogen receptors have been known to be located in the locus coeruleus(LC), where noradrenergic(NE) fibres terminate in the hypothalamus arising from cell bodies. The discharge rate of NE-ergic neurons in LC can be increased by electrical stimulation of MPO in a female rat at estrus stage, and decreased at diestrus stage. These studies help us to infer that VMN might have some modulation influence on NE-ergic neurons in LC. In order to study the pattern activities
文摘Several studies showed that sex hormone receptors are in close relationship with classical neurotransmitter neurons especially catecholaminergic(CA) neurons. There are many gonadotrophin releasing hormone (GnRH) neurons in hypothalamus and the medial preoptic area (MPO). Electrical stimulation of MPO can cause a rise in secretion
文摘Objective: To investigate the effect of different fractions from the aqueous methanolic root bark of Adansonia digitata (Linn) on the estrous cycle of female Wistar rats and to elucidate their phytochemical content. Methods: Crude aqueous methanol extract of Adansonia digitata (Linn) root bark was fractionated by column chromatography using various ratios of hexane, acetyl acetate, methanol and distilled water. Fractions with similar trails on a thin layer chromatography were pooled into four fractions. Each fraction was then screened for its phytochemical content. Forty mature Wistar female rats weighing (135±28) g with regular estrous cycles were given each fraction at two dose levels while a control group received distilled water of equal volume. Treatments were given per os for 15 days starting from the day of estrus. Vaginal smears were observed daily for the duration of each cycle, frequency of occurrence of each stage of the estrous cycle and number of cycles for 15 days before and during treatment. At the end of treatment, rats were humanely sacrificed. Ovaries and uteri were weighed and processed for histopathology. Results: Hexane acetyl acetate and acetyl acetate methanol fractions at 150 mg/kg body weight and 300 mg/kg body weight prolonged the occurrence of proestrus and diestrus and produced atretic cyst-like ovaries at 300 mg/kg body weight. Acetyl acetate methanol treated rats also had low relative ovarian weights when compared to the control. Conclusions: Sterols and triterpenes in hexane acetyl acetate and acetyl acetate methanol fractions of the root bark may be responsible for the disruption of estrous cycle in female Wistar rats and may have a contraceptive effect.
