• 作者： 張震東; 蔡淑娟; 黃火鍊
• 作者服務機構： 國立台灣大學生化科學研究所; 國立台灣大學漁業科學研究所; 中央研究院生物化學研究所
• 中文摘要： 本報告以放射免疫測定法定量離體鯉魚腦下線促性腺激素的釋放情形。促性腺激素之基礎釋放量呈現年周期變化，基礎釋放量於生殖季節前及生殖季節間顯著上升而高於生殖季節後及頂備期。正腎上腺素可刺激促性腺激素之分泌，但是和生殖季節有關；生殖季節後的腦下腺對正腎上腺素缺乏反應。 以電化學偵測法配合高效液相管柱分析，本報告分析大腦及腦下腺多巴氨及正腎上線素等神經傳導物質。腦下腺可偵測到多巴氨及正腎上腺素。正腎上腺素的含量由十一月每腦下腺625 pg升至二月1520 pg而多巴氨由十一月每腦下腺720 pg升至二月2200 pg。 本報告提出證據證明正腎上腺素於鯉魚腦下腺能刺激促性腺激素之釋放，而且和生殖季節有關。同時也發現正腎上線素於腦下腺的含量於生殖季節期間有上升現象，可能因此造成促性腺激素分泌量上升。鯉魚腦下腺多巴氨的含量周期變化和正腎上腺素的變化相似，也是於生殖季節期間上升，但是多巴氨的作用係抑制促性腺激素分泌。
• 英文摘要： Release of radioimmunoassayable gonadotropin from freshly prepared common carp pituitary frag-ments was measured using an in vitro superfusion system. Spontaneous and norepinephrine-stimulatedrelease of gonadotropin was measured. Norepinephrine, at concentrations of M, M and M,elicited significant increases in gonadotropin release from the pituitary. Interestingly, the stimulatory effectof norepinephrine was observed when pituitary was derived from animals with developing or developedgonads but not when derived from animals with regressing gonads. Spontaneous release rates of gonadotropinshowed clearly seasonal fluctuation with progressively increasing release rates entering the spawning period,reaching maximal release rates during and immediately after the spawning period. Detectable amounts of norepinephrine and dopamine within the pituitary could be measured using aliquid chromatography-electrochemical detector. Levels of norepinephrine and dopamine increased sig-nificantly from November, 1989, to February, 1990. The contents of norepinephrine were between 625 to1,520 pg per pituitary and those of dopamine were between 720 to 2,180 pg per pituitary. Significant amountsof norepinephrine, dopamine and serotonin could also be detected in the hypothalamus. The results providedevidence to show direct norepinephrine stimulation of carp gonadotropin release and to show that the extentof norepinephrine effect was affected by seasonal factors. In addition, the existence of detectable amountsof norepinephrine within carp pituitary strongly suggested a possible physiological role of norepinephrinein the regulation of gonadotropin secretion.
• 中文關鍵字： gonadotropin; pituitary; norepinephrine; dopamine; seasonal changes.
• 英文關鍵字： --