Changes in the pituitary and serum gonadotropin levels of Cranoglanis bouderius were studied at different stages of ovarian development. Based on African catfish gonadotropin (cfGTH) and its anti-serum (Racf), heterol...Changes in the pituitary and serum gonadotropin levels of Cranoglanis bouderius were studied at different stages of ovarian development. Based on African catfish gonadotropin (cfGTH) and its anti-serum (Racf), heterologous radio-immunoassay (RIA) for the gonadotropin (GTH) of Cranoglanis bouderius was developed. The pituitary GTH contents at the late development stage were significantly higher than that at the mature, ovulation or regressed stages, while serum GTH levels at maturation and ovulation were significantly higher than that at late development and regressed stages. Injection of gonadotropin-releasing hormone analogue (GnRH-A) stimulated GTH secretion. Domperidone (DOM) had no effect on the basal serum GTH level. Injection of GnRH-A and DOM significantly enhanced the GTH levels stimulated by GnRH-A alone. These results indicate that GTH release in Cranoglanis bouderius is under the dual regulation of gonadotropin releasing hormone (GnRH) and dopamine (DA) from the hypothalamus, but DA can only inhibit GTH release induced by GnRH and not basal GTH release.展开更多
S-(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-iodo-2,3-dimethoxybenzamide (proposed generic name, epidepride) is a very potent dopamine D2 antagonist. It was synthesized by five steps from 3-methoxysalicylic acid. [131I]...S-(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-iodo-2,3-dimethoxybenzamide (proposed generic name, epidepride) is a very potent dopamine D2 antagonist. It was synthesized by five steps from 3-methoxysalicylic acid. [131I]epidepride was obtained in 97.3% radiochemical yields from the corresponding 5-(tributyltin) derivative using hydrogen peroxide as the oxidant. The aryltin precursor was prepared from non-labelled epidepride by palladium-catalyzed stannylation using bis(tri-n-butyltin) in triethylamine. [131I]epidepride was stable under 4℃, and partition coefficient was 72.3 at pH 7.40. The biodistribution study in rats exihibited high localization in the striatum of the brain with the striatum/cerebellum ratio reaching 237/1 at 320 min postinjection. All these results suggest that [131I]epidepride may be used widely as a useful dopamine D2 receptor imaging agent for SPECT.展开更多
文摘Changes in the pituitary and serum gonadotropin levels of Cranoglanis bouderius were studied at different stages of ovarian development. Based on African catfish gonadotropin (cfGTH) and its anti-serum (Racf), heterologous radio-immunoassay (RIA) for the gonadotropin (GTH) of Cranoglanis bouderius was developed. The pituitary GTH contents at the late development stage were significantly higher than that at the mature, ovulation or regressed stages, while serum GTH levels at maturation and ovulation were significantly higher than that at late development and regressed stages. Injection of gonadotropin-releasing hormone analogue (GnRH-A) stimulated GTH secretion. Domperidone (DOM) had no effect on the basal serum GTH level. Injection of GnRH-A and DOM significantly enhanced the GTH levels stimulated by GnRH-A alone. These results indicate that GTH release in Cranoglanis bouderius is under the dual regulation of gonadotropin releasing hormone (GnRH) and dopamine (DA) from the hypothalamus, but DA can only inhibit GTH release induced by GnRH and not basal GTH release.
文摘S-(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-iodo-2,3-dimethoxybenzamide (proposed generic name, epidepride) is a very potent dopamine D2 antagonist. It was synthesized by five steps from 3-methoxysalicylic acid. [131I]epidepride was obtained in 97.3% radiochemical yields from the corresponding 5-(tributyltin) derivative using hydrogen peroxide as the oxidant. The aryltin precursor was prepared from non-labelled epidepride by palladium-catalyzed stannylation using bis(tri-n-butyltin) in triethylamine. [131I]epidepride was stable under 4℃, and partition coefficient was 72.3 at pH 7.40. The biodistribution study in rats exihibited high localization in the striatum of the brain with the striatum/cerebellum ratio reaching 237/1 at 320 min postinjection. All these results suggest that [131I]epidepride may be used widely as a useful dopamine D2 receptor imaging agent for SPECT.
