Melanocortin- 4 receptor (MC4R) and agouti- related peptide (AgRP) are involved in energy homeostasis in rats. According to MC4R and AgRP effects on luteinizing hormone (LH) secretion, they may influence the estrous cycle of rats. Therefore, the aim of this study was to investigate the expression of MC4R and AgRP mRNAs at different stages of estrous cycle in the rat's hypothalamus. The estrous ...

Steroid hormones are produced by the porcine uterus. We hypothesized that the uterus in pigs possesses active 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4) isomerase (3β-HSD) responsible for progesterone and androstenedione production, that uterine steroids may supplement the amount of steroid hormones produced by embryos and corpus luteum and that these steroids are necessary for maintenance of pr...

Mating stimulation, particularly vaginal-cervical stimulation, causes estrous abbreviation in female rats. In most previous studies, female rats were repeatedly tested for sexual behavior until estrous termination occurred. Thus, it was not clear whether sensory stimulation (e.g., flank stimulation, olfactory cues) received during the repeated testing procedure contributed to estrous abbreviati...

Synchronizing estrus is an effective way to maximize the use of time and labor required to detect standing estrus in cattle. However, estrous synchronization can also benefit overall herd management. Cows that are synchronized 1) exhibit standing estrus at a predicted time, 2) conceive earlier in the breeding season, 3) calve earlier in the calving season, and 4) wean calves that are older and ...

Our previous study in male rats demonstrated that bilateral administration of flutamide, an androgen receptor (AR) antagonist, into the posterodorsal medial amygdala (MePD) increased the time sniffing male odors to as high as that sniffing estrous odors, eliminating the preference for estrous odors over male odors. This made us speculate that under blockade of AR in the MePD, testosterone-deriv...

We investigated changes in the peripheral plasma concentrations of ovarian steroids and gonadotropins throughout the estrous cycle of the Microminipig (MMpig), a novel experimental animal model. The mean (± standard error of the mean (SEM)) duration of estrous and the estrous cycle in seven animals was 66.0 ± 5.2 h and 20.6 ± 0.3 days, respectively. A luteinizing hormone (LH) surge was observed...

Methomyl is an oxime carbamate pesticide that is widely used in the Philippines. This insecticide is known to be an endocrine disrupting chemical and a potent genotoxic in mammalian cells. However, limited studies were conducted specifically on its direct effects on estrous cycle and its teratogenic effect. This study aimed to (a) assess the effect of methomyl on the body weight and on the estr...

the transcriptional factor oct4 regulates pluripotency of stem cells and has an important role during oocyte growth. whereas, its role has remained ambiguous in ovarian tissue during reproductive cycle. therefore, this study was aimed to investigate the expression patterns of oct4 in mouse ovaries during the normal estrous cycle. adult national medical research institute mice were classified as...

The objectives of this study were to determine 1) the ability of charcoal-extracted bovine follicular fluid (bFF) to suppress endogenous follicle stimulating hormone (FSH) at various stages of the estrous cycle and 2) the effects of suppression of FSH on luteal function and lengths of the current and subsequent estrous cycles. Twenty-six mature ewes were assigned randomly to receive 5 ml of eit...

To investigate uterine fluid and serum copper (Cu) and zinc (Zn) variations during the estrous cycle in water buffaloes, 71 genital tracts and blood samples were collected from the abattoir in Urmia, Iran. The phase of the estrous cycle was determined by examining ovarian structures; 18, 15, 16 and 22 were pro-estrous, estrous, met-estrous and diestrous, respectively. The uterine fluid was coll...