高原鼠兔发情周期性激素与性器官变化特征OA北大核心CSTPCD

In order to study the phenotypic change of estrus in female plateau pika(Ochotona curzoniae)and its relation-ship with sex hormone level and reproductive organ development,plateau pikas in breeding period and non-breeding pe-riod were selected for our experiment.The periodic vaginal changes were detected by vulvar morphological observation and vaginal smear,and the result showed that the estrus cycle of breeding pika was between 7 and 11 days and the oes-trus stage lasted 3 to 4 days,while the vaginal state of non-breeding pika was close to proestrus stage.The serum and urine samples of pikas from oestrus,dioestrus and non-breeding periods were collected,and the concentrations of estradi-ol and progesterone were detected by enzyme-linked immunosorbent assay.The serum estradiol content of oestrus pika was significantly higher than those of dioestrus and non-breeding pikas(P=0.033 8),while the serum progesterone con-tent of non-breeding pika was significantly higher than those of oestrus and dioestrus pikas(P=0.019 5).The sensitivi-ty of urine detection was weaker than serum detection,and the difference was only found in the urine estradiol between oestrus and non-breeding periods(P=0.000 9).The ovarian weight of oestrus pika was significantly higher than those of dioestrus and non-breeding pikas(P＜0.000 1),and the ovarian weight of dioestrus pika was also significantly higher than that of non-breeding pika(P=0.007 2).Hematoxylin and eosin staining showed that the oestrus ovary was mainly composed of antral follicles,the dioestrus ovary contained secondary follicle,antral follicle and corpus luteum.Addition-ally,there were large amounts of primordial and primary follicles in the non-breeding ovary.There were three distinct layers in the uterus of plateau pika,including endometrium,myometrium and perimetrium.At the oestrus period,the en-dometrium was thicker and the glands and blood vessels were abundant;at the dioestrus period,the numbers of glands and blood vessels were dramatically reduced;at the non-breeding period,the uterus was obviously degraded with the thinner endometrium and the glands and blood vessels were almost completely disappeared.We confirmed the validity of the vaginal smear method in determining the estrus cycle of plateau pika and described the characteristics of sex hor-mone level and sex organ histology in pikas from different estrus periods.This study can provide an important reference for clarifying the regulation mechanism of seasonal reproduction in female plateau pika.