The experiments reported here were designed to determine if there are sex- and/or estrus cycle-dependent differences in amphetamine (AMPH)-elicited rotational behavior in unlesioned rats. Whole brain or striatal levels of AMPH produced by systemic administration of the drug were also measured. At all doses tested (1.0-10.0 mg/kg) systemic administration of AMPH resulted in significantly higher ...

Muskox farming is an emerging industry in Alaska. For such an endeavor to succeed, it is necessary to develop fundamental husbandry tools specifically for this species. This study examined the role of the bull in the onset of seasonal ovarian activity and the synchrony of estrus and tested the efficacy of a radiotelemetric estrus detection system. Twenty parous female muskoxen, ranging in age f...

An estrus synchronization protocol (7-11 Synch) was developed to synchronize the first follicular wave and timing of ovulation in postpartum beef cows. In Exp. 1, follicular development and timing of ovulation in response to the following protocol were evaluated. Beef heifers (n = 12) and cows (n = 6), at random stages of the estrous cycle, were fed melengestrol acetate (MGA; .5 mg x animal(-1)...

This study examined the uterine oxytocin- (OTR) and estrogen- (ER) receptor mRNA levels during and after pseudopregnancy (PSP) in rats. An increased OTR mRNA level was observed from day 14 of PSP, and the maximal level was attained during the following proestrus. The levels of ERalpha mRNA were low during PSP and significantly increased during the following estrus. The level of ERbeta mRNA was ...

The effect of time of OvuGel administration on timing of estrus and ovulation and fertility results was evaluated in a study involving 448 gilts that had been synchronized for estrus by administering Matrix for 14 d. A RCBD with the following treatments was used: 1) Control (no OvuGel administration), 2) OvuGel administration on d 5 (118 h) after the end of Matrix administration (OV5), and 3) O...

Vascular endothelial growth factor (VEGF) is a well known angiogenic factor that has been suggested to play some physiological roles in reproductive organs. To clarify whether VEGF is involved in regulating bovine endometrial function locally, in experiment 1, we determined the expression of VEGF, VEGF receptor (VEGFR) 1 and VEGFR2 throughout the estrous cycle in endometrial tissues. Endometria...

The microbial population of the uterus fluctuates during the estrous cycle. Microflora of uterus may affect the establishment and maintenance of pregnancy in bitches. The endoscopic samples obtained from the vagina and uterus of 20 female adult mixed‑breed dogs. The uterine lavage samples were prepared for cytology, bacterial (aerobic and anaerobic) and fungal cultures. Uterine tissue samples w...

Corpus luteum (CL) function following spontaneous or prostaglandin F2 alpha-induced estrus was studied in 27 Brahman cows and 16 Brahman heifers. Females received one injection of 0, .38, .75 or 2.25 mg alfaprostol (PGF)/100 kg body weight at 12 +/- .1 d post-estrus. Serum progesterone (P4) during CL formation, following the subsequent estrus, increased over time (P less than .001, 1 to 13 d po...

Treatment with GnRH and PGF2 alpha is a practical method for controlling ovarian follicular and luteal functions and increasing the precision of estrus synchronization in cyclic and acyclic postpartum cows and heifers. This method reduces considerably the period of time needed for estrus detection; it synchronizes the estrous cycle of 70 to 80% of the cyclic cows to within a 4-d interval withou...

When conducting vaginal irritation studies, ovariectomized rats or rabbits are typically used according to practical reports. In the present study, we evaluated the influence of the estrus cycle in a vaginal irritation study using intact rats and ovariectomized rats, which exhibit a late diestrus-like condition, to determine whether intact rats can be useful for evaluating vaginal irritancy. Ra...