摘要
利用 350至 4 50日龄的就巢粤黄鸡观察多巴胺 (DA)和 5 羟色胺 ( 5 HT)受体拮抗剂氯丙嗪和赛更啶对就巢的影响。就巢第 2d开始每天口服氯丙嗪 60mg/ (kg·d)或赛更啶 8mg/ (kg·d) ,7d后或于就巢终止后停止药物处理。试验 1:13只氯丙嗪处理鸡中 92 3% ( 12 / 13)于处理后5 4± 1 1d终止就巢 ;15只赛更啶处理鸡有 60 0 % ( 9/ 15)在处理后 3 2± 0 3d终止就巢 ;全部( 10 0 % ) 10只同时处理氯丙嗪和赛更啶的鸡于处理后 3 2± 0 3d终止就巢 ;8只对照组鸡在不受任何处理时持续就巢 ,其就巢期被主观认为 2 2d。试验 2 :7只就巢鸡在就巢的第 2、4、9、14和 19d血浆PRL水平维持在 2 0 0～ 4 0 0ng/ml之间 ;9只氯丙嗪处理后终止就巢的 7只鸡以及 13只赛更啶处理后终止就巢的 6只鸡 ,血浆PRL由就巢第 2d与对照组类似的高水平急剧下降到第 4d小于 2 0ng/ml,并至第 19d一直处于较低水平。对照组在持续就巢期间的血浆LH水平低于 1 0ng/ml,而用药后终止就巢鸡的血浆LH水平从处理前的小于 1 0ng/ml逐渐上升至第 19天的 3 0ng/ml左右。药物处理后仍未终止就巢鸡的血浆PRL和LH水平都与对照组的类似。以上结果说明用DA和 5 HT受体拮抗剂氯丙嗪和赛更啶处理后 ,抑制了垂体PRL的分泌并使鸡终止就巢 ,在整体水平证明了?
Two experiments were conducted on 350 to 450 day old broody chicken hens of the synthetic Yuehuang strain to investigate the effects of dopamine and 5 HT receptor antagonists chlorpromazine and cyproheptadine on broodiness Drugs were orally administered at 60mg/(kg·d) chlorpromazine or 8mg/(kg·d) cyproheptadine starting on day 2 of broodiness for 7 days or stopped when hens terminated broodiness In experiment 1,12 of 13 chlorpromazine treated (92 3%)hens terminated broodiness after 5 4±1 1 days of treatment,and 9 of 15 cyproheptadine treated (60 0%) hens terminated broodiness after 3 2±0 3 days of treatment,and all 10 (100%)hens treated with chlorpromazine and cyproheptadine simultaneously terminated broodiness after 3 2±0 3 days of treatment Eight control hens continued to brood so their broody period was arbitrarily defined as 22 days Experiment 2 monitored changes in blood concentrations of prolactin and LH in correlation to termination of broodiness as a consequence of treatment with chlorpromazine or cyproheptadine In 7 non treated control broody hens,plasma PRL concentrations in samples taken on day 2,4,9,14 and 19 of broodiness were elevated and in the range of 200～400 ng/ml In seven out of 9,and 6 out of 13 hens treated with chlorpromazine or cyproheptadine terminated broodiness following drug treatment,blood PRL levels all decreased from high levels on day 2 of broodiness to levels below 20 ng/ml on day 4 and maintained at low levels to day 19 after onset of broodiness Blood LH concentrations of these hens gradually increased from initial value of less than 1 ng/ml on day 2 to values about 3 0 ng/ml on day 19 after onset of broodiness Hens maintaining broodiness even after being treated with drugs had PRL and LH levels similar to those of controls These results demonstrated for the first time in vivo that DA and 5 HT receptors antagonists terminated maintenance of broodiness by inhibiting secretion of PRL from pituitary gland These findings indicate that hypothalamic DA and 5 HT activities are the upmost causes of development and maintenance of broodiness above hypothalamic VIP and pituitary PRL
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
2000年第6期487-492,共6页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
基金
教育部回国留学生启动基金! (教留司研 [1994]99)
