MLT埋植剂对准备配种期水貂卵巢形态学和显微结构的影响

Effects of melatonin implant on morphology and microstructure of mink’s ovaries in mating preparation period

为探讨褪黑素(melatonin,MLT)埋植剂埋植不同时间对准备配种期水貂卵巢形态学和显微结构的影响,试验随机将75日龄、平均体重为(875±5)g的120只健康雌性白色水貂平均分为A、B、C、D 4组,于7月2日对A、C组水貂颈部皮下埋植MLT埋植剂1粒(含MLT 18 mg),B、D组作为对照组不做任何处理,分别在埋植满98 d(10月8日)的A、B组及埋植满158 d(12月7日)的C、D组宰杀3只水貂并采集卵巢,进行形态学检测和显微结构观察。结果表明:与同期对照组相比,埋植满98 d和158 d,A、C两组水貂卵巢体积均显著增大(P<0.05),次级卵泡直径极显著增大(P<0.01),三级卵泡的直径和卵母细胞直径显著增加(P<0.05),生殖上皮细胞分别提前发育为椭圆状和柱状,三级卵泡颗粒细胞层数增多;与D组相比,A组卵巢长径、宽径、厚径、体积、次级卵泡直径、三级卵泡直径和卵母细胞直径差异不显著(P>0.05)。说明埋植MLT埋植剂满98 d和158 d可促进水貂卵巢发育,埋植满98 d时卵巢可提前发育至158 d的对照组水平。

The purpose of the experiment was to study the effects of melatonin(MLT)implant time on microstructure of mink’s ovaries in mating preparation period.A total of 120 healthy female white minks aged 75 days with an average body weight of(875±5)g were randomly divided into four groups(Group A,B,C and D).One MLT implant(including MLT18 mg)was implanted subcutaneously in the neck of groups A and C on July 2,and groups B and D were treated as control group without any treatment.The ovaries of 3 minks were collected from groups A and B implanted for 98 days(October 8),and groups C and D implanted for 158 days(December 7),respectively,for morphological detection and microscopic structure observation.The results showed that compared with the control group,after 98 and 158 days of implantation,the ovary volume in groups A and C was significantly increased(P<0.05);the diameter of secondary follicle was extremely significantly increased(P<0.01);the diameter of tertiary follicle and oocyte were significantly increased(P<0.05),and the germ epithelium cells developed into ellipses and columns in advance,respectively.Tertiary follicle granulosa cell layer increased.Compared with group D,there were no significant differences in ovary length diameter,width diameter,thickness diameter,volume,secondary follicle diameter,tertiary follicle diameter and oocyte diameter in group A(P>0.05).Under the experimental conditions,MLT implantation for 98 days and 158 days could promote the development of mink ovary,and the ovary could be predeveloped to the control level of 158 days after implantation.