Antifertility Effects And Mechanisms Of Cabergoline On Rattus Losea

Contraception control can reduce the birth rate instead of increasing mortality of rodent population One hand, it influences animal reproductive capability, the other hand, steriled individuals impact hierarchical relation and social structure of populations, and cause reproductive interference to normal animals. In order to understand the effects and mechanisms of cabergoline and the duration of infertility on Rattus losea, forty male and female rats were randomly divided into five groups and treated with cabergoline for3consecutive days at varying doses (0,50, and100μg/kg). We observed these indices of reproductive organs, hormone content and the activities of concered enzymes in testis and so on; we also observed some social behaviors concerd reproduction between the same sex and the opposite sex.1. The male Rattus losea treated with50μg/kg cabergoline for3consecutive days and on24d after administration, the wet weight of testis and epididymis decreased, and testicular tissue sections showed that testicular seminiferous epithelium atrophied, spermatogenic cells, Leydig and Sertoli cells were damaged or even fell off and disintegrated in seminiferous tubule, lumen were empty, only a few spermatogonia and loosely arranged. Time course affected sperm density and sperm deformity rate. Drug dosage and time course significantly affected male sperm vitality at50μg/kg. Moreover, cabergoline significantly decreased the percentage of’ rapid’,’slow or sluggish’progressive motility sperms, and increased the percentage of "immotility" sperms.100μg/kg cabergoline treatment decreased the ACP enzyme activity, and restored on24d after cabergoline administration. The dose increased will decreased the amount of increasing of LDH enzyme activity, and recovery on24d after cabergoline treatment. The activity of GSH-Px was significantly increased at24d at100μg/kg cabergoline compared with the control group, and more than those in50μg/kg group. Compared with the control, at100μg/kg cabergoline, testosterone concentrations decreased significantly by48.6%at7d. LH concentrations were significantly reduced by cabergoline dosage and time course. Hence, cabergoline may reduce luteinizing hormone level, and impair sperm quality, and significantly affect the activities of enzymes in testis, which hint weakening reproductive effects on male R. losea.2. Dosage of50μg/kg cabergoline treatment on7d after administration, the wet weight of ovary was higher than that of control group and24d after administration. Cabergoline affected the uterus significantly of female Rattus losea, the suffer uterus edema, uterine cavity filled with liquid and uterus wall gores. The microstructure of ovary showed that50μg/kg cabergoline treatment increased the number of ovarian tissue atretic follicles slightly, and interstitial gland developed. And the100ug/kg cabergoline treatment decreased the number of follicles in ovarian tissue cells. There were no dose or time course of cabergoline dependence of serum estradiol and progesterone concentration in females. In contrast, the PRL content in females was affected by time course of cabergoline significantly, and the dosage dependence of cabergoline did not indicate significantly. The present study suggested that cabergoline interferenced PRL and estrogen secretion in females, inhibited follicular maturation and suppressed ovulation, which may reduce reproductive effects on female R. losea. 3. Cabergoline also indicated negative effects on the investigative and aggressive behavior of male R. losea, and the time of self-grooming and resting were increased. The investigation time of the treated females toward the C-female was longer than that of the pre-treatment group, but the self-grooming and resting time were shorter than pre-treatment.50μg/kg cabergoline reduced the aggression time of females toward the C-female, but increased the defense time. The frequency of investigation and self-grooming and resting exhibited significant differences between the pre-treatment and the post-treatment of100μg/kg cabergoline treatment male that encountered a C-female counterpart. The aggression times and frequency were reduced in cabergoline-treated males that encountered female rats than the pre-treatment groups. When cabergoline-treated females encountered normal male rats, the aggression and defense behavior were decreased compared with pre-treatment. Furthermore, the behavioral data in our experiment suggested that cabergoline treatment can significantly disturb the inter-or intra-sexual social behavior of R. losea. Cabergoline reduced aggressive behavior of individuals toward normal rats, treatment females showed more friendly behavior to normal males than pre-treatment, may induce the competitively reproductive interference by sterile individuals to reproductive ones.