Gene expression in the amygdala and hippocampus of cyclic and acyclic gilts

Age at first estrus is the earliest phenotypic indicator of future reproductive success of gilts. Prebreeding anestrus is a major reason for reproductive failure leading to culling of replacement gilts. The two types of prebreeding anestrus are delay in attaining puberty (prepubertal anestrus, PPA) and silent ovulation (behavioral anestrus, BA). Neural tissues such as amygdala and hippocampus play a major role in regulating sexual behavior, social interactions, and receptivity to males. Differences in gene expression in the amygdala and hippocampus of gilts were analyzed in three comparisons; 1) PPA cases and cyclic controls at follicular phase of estrous cycle, 2) BA cases and cyclic controls at luteal phase of estrous cycle, and 3) gilts at different stages of the ovarian cycle (cyclic gilts at follicular phase and luteal phase of estrous cycle) to gain functional understanding of how these rarely studied tissues may differ between pubertal phenotypes and different stages of the estrous cycle of gilts. Differentially expressed genes (DEG) between PPA and BA cases and their respective cyclic controls were involved in neurological and behavioral disorders as well as nervous system functions that could directly or indirectly involved in development of behaviors related to estrus. The comparison between cyclic follicular and luteal phase control gilts identified the greatest number of DEG in the hippocampus and amygdala. These DEG were involved in adult neurogenesis and neural synapse (e.g., GABAergic, dopamine, cholinergic) suggesting that these tissues undergo structural changes and synaptic plasticity in gilts. This is the first report to demonstrate that the stage of estrous cycle is associated with dynamic changes in gene expression within porcine hippocampus and amygdala and indicates a role of gonadal steroids in regulating their biology.

STRATEGIES TO INCREASE FERTILITY DURING FIXED-TIME ARTIFICIAL INSEMINATION IN BEEF CATTLE

The application of Fixed Time Artificial Insemination (FTAI) protocols has strongly boosted artificial insemination in Brazilian bovine herds. The control of the estrous cycle with protocols based on progesterone and estrogen involves synchronizing the emergence of a follicular wave, controlling the progesterone phase, and inducing ovulation in a synchronized manner. The increase in pregnancy rates starts with the preparation of the breeding season and the choice of protocols and females. Thereafter, based on the characteristics of the property and the lots of animals, small adjustments can be made to the hormonal protocols as needed. Finally, resynchronization can increase usability by allowing multiple inseminations within short periods. The search for new strategies is of paramount importance for the development of the FTAI protocol and the increase in final pregnancy rates. Thus, this review sought to highlight the main critical points and adjustments of the FTAI protocols and their applicability in the reproduction of beef cattle.

Effect of Electroacupuncture on Reproductive Disorders and Insulin Resistance in a Murine Polycystic Ovary Syndrome Model

Polycystic ovarian syndrome (PCOS) is a common, complex, and heterogeneous endocrine and metabolic disorder. There is no standardized treatment, and it therefore requires individualized therapies according to the symptoms and pathogenesis of each patient. The present study aimed to determine the effect of electroacupuncture at the acupoints Zusanli (ST36), Sanyinjiao (SP6), and Neiguan (PC6) on reproductive disorders and insulin resistance in a murine model of PCOS induced by dehydroepiandrosterone (DHEA). Vaginal smear analysis was used to determine mice estrous cycle; intraperitoneal glucose and insulin tolerance tests were adopted to analyze metabolic characteristics; enzyme-linked immunosorbent assay was used to measure hormone levels; gene expression was quantified with real-time PCR; hematoxylin and eosin staining was used to observe ovarian morphology. We observed disordered estrous cycle, polycystic ovarian morphology, and higher levels of homeostasis model assessment-insulin resistance (HOMA-IR) and testosterone (T), indicating successful modeling of PCOS. DHEA increased levels of estrogen (E2), progesterone (P), testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone (FSH), and EA treatment restored them to levels seen in the control group. EA reduced the days in estrus caused by DHEA, improved the abnormal sex hormone receptor genes, and attenuated the DHEA-induced histomorphological changes in mouse ovaries. The average expressions of the androgen receptor (AR), estrogen receptor (ER), luteinizing hormone receptor (LHR), and follicle-stimulating hormone receptor (FSHR) genes in the ovary greatly increased after DHEA treatment and significantly decreased in the DHEA + EA group. After EA treatment, the cystic follicle (CF) number was reduced and corpora lutea (CL) increased in the DHEA + EA group compared to the DHEA group. EA improved glucose intolerance and insulin intolerance. Statistical analysis of intraperitoneal glucose tolerance test-area under curve (IPGTT-AUC) glucose levels revealed a significant decrease in DHEA group mice compared to the control and DHEA + EA groups. EA was found to restore fasting blood glucose, fasting serum insulin, and HOMA-IR. In summary, our study suggests that EA has a remarkable effect in the DHEA-induced murine PCOS model. Management of EA could improve estrous cycle, hormonal disorders, abnormal sex hormone receptors in ovaries, ovary morphology, and insulin resistance in PCOS mice.

Effect of Penicillin on Reproductive Function in Female Wistar Rats

This study was designed to investigate the effect of penicillin on reproductive function in female Wistar rats. Fifteen female rats (120 – 160 g) were used for the estrous cycle and histopathological studies. Penicillin (17.14 mg/kg) was administered orally on daily basis for 21 and 50 days respectively for the estrous cycle and histological studies. Estrous cycle was carried out using the technique of Marcondes et al., histologies of the ovaries and uteri were also carried out. Data were analysed using descriptive statistics and student’s t-test at p=0.05. Treatment of rats for 21 days with penicillin (17.14 mg/kg) produced significant (p<0.05) increments in the estrous and metestrous phases as well as a significant (p<0.05) reduction in the proestrous phase of the estrous cycle relative to their respective controls. The histopathological study presented with a moderate endometrial congestion. It can therefore be concluded that penicillin probably has a pro-fertility effect with a moderate deleterious effect on the uteri at histological level in female Wistar rats.

Effect of Artesunate on Reproductive Function in Female Wistar Rats

This study was designed to investigate the effect of artesunate on reproductive function in female Wistar rats. Fifteen female rats (120 – 160 g) were used for the estrous cycle and histopathological studies. Artesunate (1.43 mg/kg) was administered orally on daily basis for 21 and 50 days respectively for the estrous cycle and histological studies. Estrous cycle was carried out using the technique of Marcondes et al., histologies of the ovaries and uteri were also carried out. Data were analysed using descriptive statistics and student’s t-test at p=0.05. Treatment of rats for 21 days with artesunate (1.43 mg/kg) produced significant (p<0.05) increments in the estrous and metestrous phases as well as a significant (p<0.05) reduction in the proestrous phase of the estrous cycle relative to their respective controls. The histopathological study presented with ovarian medullar that is severely congested (hemorrhagic) including expanded lumen of the endometrial glands. It can therefore be concluded that artesunate probably has pro-fertility effect with deleterious effect on the ovaries at histological level in female Wistar rats.

Effect of Methotrexate on Reproductive Function in Female Wistar Rats

This study was designed to investigate the effect of methotrexate on reproductive function in female Wistar rats. Eighteen female rats (120 – 160 g) were used for the estrous cycle and histopathological studies. Methotrexate (0.071 mg/kg) was administered orally on daily basis for 21 and 50 days respectively for the estrous cycle and histological studies. Estrous cycle was carried out using the technique of Marcondes et al., histologies of the ovaries and uteri were also carried out. Data were analysed using descriptive statistics and student’s t-test at p=0.05. Treatment of rats for 21 days with methotrexate (0.071 mg/kg) produced significant (p<0.05) reductions in the proestrous and estrous phase of the estrous cycle as well as significant (p<0.05) increments in the metestrous and diestrous phases of the estrous cycle relative to their respective controls. The histopathological study revealed that treatment of rats with methotrexate (0.071 mg/kg) for 50 days presented with ovarian medullary part that is congested and oedematous as well as with multiple foci of hemorrhage within the endometria. It can therefore be concluded that that methotrexate probably has dominant pro-fertility effect, but also probably induced deleterious effects on the ovaries and uteri in female Wistar rats.

Effect of Chloramphenicol on Reproductive Function in Female Wistar Rats

This study was designed to investigate the effect of chloramphenicol on reproductive function in female Wistar rats. Fifteen female rats (120 – 160 g) were used for the estrous cycle and histopathological studies. Chloramphenicol (7.14 mg/kg) was administered orally on daily basis for 21 and 50 days respectively for the estrous cycle and histological studies. Estrous cycle was carried out using the technique of Marcondes et al., histologies of the ovaries and uteri were also carried out. Data were analysed using descriptive statistics and student’s t-test at p=0.05. Treatment of rats for 21 days with chloramphenicol (7.14 mg/kg) produced significant (p<0.05) reductions in the proestrous and diestrous phases as well as a significant (p<0.05) increment in the estrous phase of the estrous cycle relative to their respective controls. The histopathological study presented with no visible lesions on the ovaries and uteri, but few endometrial glands have expanded lumen. It can therefore be concluded that chloramphenicol probably has pro-fertility as well as exhibits non-deleterious effects on the reproductive tissues of female Wistar rats.