-
Iranian Journal of Basic Medical... Apr 2019Baicalein (BC), a phytoestrogen of the flavonoid family shows beneficiary and adverse effects. Effect of BC on reproduction is still not understood. Reproductive toxic...
OBJECTIVES
Baicalein (BC), a phytoestrogen of the flavonoid family shows beneficiary and adverse effects. Effect of BC on reproduction is still not understood. Reproductive toxic effects on female mice were tested in this study.
MATERIALS AND METHODS
Inseminated Wistar mice were divided into four groups and administered IP with 30, 60, and 90 mg/Kg body weight of BC on gestation days 11, 13, 15, and 17, and controls treated with DMSO. They were allowed to deliver pups and offspring were separated gender-wise on day 21. The stages of the estrus cycle and its lengthlengths of three successive cycles were measured from day 38 of young females. The mature female offspring of at 60 days age havewere cohabited with control males and the female reproductive endpoints and body weights of dams were measured.
RESULTS
The BC exposure increased the length of the estrus cycle, especially the metestrus and diestrus phases were prolonged among other phases of the estrus cycle. Recorded significant reduction in the body weights (<0.05) of prenatally BC exposed dams on 8 and 18 days of gestation. A significant increase in the conception time (<0.0001), pre (53.42%) and post (8.82%) implantation loss, and resorptions (=0.055), whereas a significant decrease in the number of implantations and live fetuses (<0.0001) were found in BC exposed dams in a dose-dependent manner.
CONCLUSION
Prenatal BC exposure prolonged the estrus cycle due to the augmented length of metestrus and diestrus phase, and is reportingreported for the first time. Female fertility output in mice is affected severely by prenatal BC exposure.
PubMed: 31168352
DOI: 10.22038/ijbms.2019.33376.7972 -
Physiological Reports Mar 2019Emerging evidence suggests that sex differences exist in the control of lung innate immunity; however, the specific roles of sex hormones in the inflammatory response,... (Comparative Study)
Comparative Study
Emerging evidence suggests that sex differences exist in the control of lung innate immunity; however, the specific roles of sex hormones in the inflammatory response, and the mechanisms involved are unclear. Here, we investigated whether fluctuations in circulating hormone levels occurring in the mouse estrous cycle could affect the inflammatory response to air pollution exposure. For this, we exposed female mice (C57BL/6J, 8 weeks old) at different phases of the estrous cycle to 2 ppm of ozone or filtered air (FA) for 3 h. Following exposure, we collected lung tissue and bronchoalveolar lavage fluid (BAL), and performed lung function measurements to evaluate inflammatory responses and respiratory mechanics. We found a differential inflammatory response to ozone in females exposed in the luteal phase (metestrus, diestrus) versus the follicular phase (proestrus, estrus). Females exposed to ozone in the follicular phase had significantly higher expression of inflammatory genes, including Ccl2, Cxcl2, Ccl20, and Il6, compared to females exposed in the luteal phase (P < 0.05), and displayed differential activation of regulatory pathways. Exposure to ozone in the follicular phase also resulted in higher BAL neutrophilia, lipocalin levels, and airway resistance than exposure in the luteal phase (P < 0.05). Together, these results show that the effects of ozone exposure in the female lung are affected by the estrous cycle phase, and potentially hormonal status. Future studies investigating air pollution effects and inflammation in women should consider the menstrual cycle phase and/or circulating hormone levels.
Topics: Airway Resistance; Animals; Estradiol; Estrous Cycle; Female; Gene Expression Regulation; Gene Regulatory Networks; Inflammation Mediators; Lung; Luteinizing Hormone; Mice, Inbred C57BL; Neutrophil Infiltration; Ozone; Pneumonia; Progesterone; Respiratory Mechanics; Transcriptome
PubMed: 30848106
DOI: 10.14814/phy2.14026 -
Behavioural Brain Research Apr 2019Although there are clear sex differences in individuals with schizophrenia, preclinical research has historically favored the use of male rats for behavioral studies....
Although there are clear sex differences in individuals with schizophrenia, preclinical research has historically favored the use of male rats for behavioral studies. The methylazoxymethanol acetate (MAM) model is a gestational disruption model of schizophrenia and has been reported to produce robust behavioral, neurophysiological and anatomical alterations in male rats; however, whether similar effects are observed in female rats is less well known. In this study, we characterize the behavioral, electrophysiological and molecular alterations induced by prenatal MAM administration in female rats while also examining the potential effects of the estrous cycle on schizophrenia-like behaviors. Specifically, MAM-treated female offspring demonstrated deficits in sensorimotor gating, latent inhibition, and social interaction, consistent with those observed in male animals. Interestingly, amphetamine-induced locomotor activity, latent inhibition, and social interaction were also affected by the estrous cycle. To examine the potential cellular mechanisms associated with these behavioral alterations, we analyzed hippocampal parvalbumin (PV) interneurons. Deficits in PV interneuron number and high-frequency gamma oscillations were disrupted in female MAM-treated rats regardless of the stage of the estrous cycle; however, alterations in PV protein expression were more prominent during metestrus/diestrus. Taken together, these data suggest that prenatal MAM exposure in female rats produces robust behavioral, molecular, and physiological deficits consistent with those observed in the male MAM model of schizophrenia. Moreover, our results also suggest that specific schizophrenia-like symptoms can also be influenced by the estrous cycle, and further emphasize the importance of sex as a biological variable when using preclinical models.
Topics: Amphetamine; Animals; Behavior, Animal; Disease Models, Animal; Estrous Cycle; Female; Hippocampus; Methylazoxymethanol Acetate; Parvalbumins; Pregnancy; Prenatal Exposure Delayed Effects; Rats, Sprague-Dawley; Schizophrenia; Sensory Gating
PubMed: 30660776
DOI: 10.1016/j.bbr.2019.01.031 -
Physiological Reports Dec 2018Previous studies indicate women have a higher blood alcohol (i.e., ethanol) and acetaldehyde concentration after consuming an equivalent amount of alcohol, and that...
Previous studies indicate women have a higher blood alcohol (i.e., ethanol) and acetaldehyde concentration after consuming an equivalent amount of alcohol, and that women are more susceptible to the long-term negative health effects of alcohol. However, there is a paucity of data pertaining to whether there is a sexual dimorphic response in skeletal muscle to alcohol. Adult male and female Sprague-Dawley rats were used and the primary endpoint was in vivo determined muscle (gastrocnemius) protein synthesis (MPS). The initial study indicated MPS did not differ in female rats during proestrus, estrus, metestrus, or diestrus; hence, subsequent studies used female rats irrespective of estrus cycle phase. There was no difference in MPS between male and female rats under basal fasted conditions, and the time- and dose-responsiveness of both groups to the inhibitory effect of acute alcohol did not differ. The ability of alcohol to suppress MPS was comparable in male and female rats pretreated with alcohol dehydrogenase inhibitor 4-methylpyrazol. Chronic alcohol feeding for 6 weeks decreased MPS in male but not in female rats; however, MPS was reduced in both sexes at 14 weeks. Finally, oral gavage of leucine increased MPS similarly in male and female rats and chronic alcohol feeding for 14 weeks prevented the anabolic effect in both sexes. These data suggest normal fluctuations in ovarian hormones do not significantly alter MPS in female rats, and that there is no sexual dimorphic response to the effects of acute alcohol intoxication on MPS. While chronic alcohol consumption appeared to decrease MPS at an early time point in male compared to female rats, there was no sex difference in the suppressive effect of alcohol at a later time point. Overall, these data do not support the prevailing belief that females are more susceptible than males to alcohol's catabolic effect on MPS.
Topics: Alcohol Dehydrogenase; Alcohol Drinking; Animals; Central Nervous System Depressants; Enzyme Inhibitors; Estrogens; Ethanol; Female; Fomepizole; Leucine; Male; Metabolism; Muscle Proteins; Muscle, Skeletal; Rats; Rats, Sprague-Dawley; Sex Factors
PubMed: 30512248
DOI: 10.14814/phy2.13929 -
Scientific Reports Oct 2018Oviductosomes (OVS) are nano-sized extracellular vesicles secreted in the oviductal luminal fluid by oviductal epithelial cells and known to be involved in sperm...
Oviductosomes (OVS) are nano-sized extracellular vesicles secreted in the oviductal luminal fluid by oviductal epithelial cells and known to be involved in sperm capacitation and fertility. Although they have been shown to transfer encapsulated proteins to sperm, cargo constituents other than proteins have not been identified. Using next-generation sequencing, we demonstrate that OVS are carriers of microRNAs (miRNAs), with 272 detected throughout the estrous cycle. Of the 50 most abundant, 6 (12%) and 2 (4%) were expressed at significantly higher levels (P < 0.05) at metestrus/diestrus and proestrus/estrus. RT-qPCR showed that selected miRNAs are present in oviductal epithelial cells in significantly (P < 0.05) lower abundance than in OVS, indicating selective miRNA packaging. The majority (64%) of the top 25 OVS miRNAs are present in sperm. These miRNAs' potential target list is enriched with transcription factors, transcription regulators, and protein kinases and there are several embryonic developmentally-related genes. Importantly, OVS can deliver to sperm miRNAs, including miR-34c-5p which is essential for the first cleavage and is solely sperm-derived in the zygote. Z-stack of confocal images of sperm co-incubated with OVS loaded with labeled miRNAs showed the intracellular location of the delivered miRNAs. Interestingly, individual miRNAs were predominantly localized in specific head compartments, with miR-34c-5p being highly concentrated at the centrosome where it is known to function. These results, for the first time, demonstrate OVS' ability to contribute to the sperm's miRNA repertoire (an important role for solely sperm-derived zygotic miRNAs) and the physiological relevance of an OVS-borne miRNA that is delivered to sperm.
Topics: Animals; Cell Proliferation; Centrosome; Embryonic Development; Endocytosis; Estrous Cycle; Extracellular Vesicles; Female; Gene Expression Profiling; Gene Expression Regulation; Gene Ontology; Male; Mice; MicroRNAs; Oviducts; Reproducibility of Results; Spermatozoa
PubMed: 30382141
DOI: 10.1038/s41598-018-34409-4 -
International Neurourology Journal Sep 2018To characterize the relationship between serum estradiol levels and the expression of glucose transporter type 4 (Glut4) in the pubococcygeus and iliococcygeus muscles...
PURPOSE
To characterize the relationship between serum estradiol levels and the expression of glucose transporter type 4 (Glut4) in the pubococcygeus and iliococcygeus muscles in female rats.
METHODS
The muscles were excised from virgin rats during the metestrus and proestrus stages of the estrous cycle, and from sham and ovariectomized rats implanted with empty or estradiol benzoate-filled capsules. The expression of estrogen receptors (ERs) was inspected in the muscles at metestrus and proestrus. Relative Glut4 expression, glycogen content, and serum glucose levels were measured. Appropriate statistical tests were done to identify significant differences (P≤0.05).
RESULTS
The pubococcygeus and iliococcygeus muscles expressed ERα and ERβ. Glut4 expression and glycogen content in the pubococcygeus muscle were higher at proestrus than at metestrus. No significant changes were observed in the iliococcygeus muscle. In ovariectomized rats, the administration of estradiol benzoate increased Glut4 expression and glycogen content in the pubococcygeus muscle alone.
CONCLUSION
High serum estradiol levels increased Glut4 expression and glycogen content in the pubococcygeus muscle, but not in the iliococcygeus muscle.
PubMed: 30286578
DOI: 10.5213/inj.1836116.058 -
Epilepsy Research Nov 2018Childhood absence epilepsy (CAE) is the most common pediatric epilepsy syndrome and is characterized by typical absence seizures (AS). AS are non-convulsive epileptic...
Childhood absence epilepsy (CAE) is the most common pediatric epilepsy syndrome and is characterized by typical absence seizures (AS). AS are non-convulsive epileptic seizures characterized by a sudden loss of awareness and bilaterally generalized synchronous 2.5-4 Hz spike and slow-wave discharges (SWD). Gamma butyrolactone (GBL) is an acute pharmacological model of AS and induces bilaterally synchronous SWDs and behavioral arrest. Despite the long use of this model, little is known about its strain and sex-dependent features. We compared the dose-response profile of GBL-evoked SWDs in three rat strains (Long Evans, Sprague-Dawley, and Wistar), and examined the modulatory effects of estrous cycle on SWDs in female Wistar rats. We evaluated the number of seizures, the cumulative time seizing, and the average seizure duration as a function of dose, strain, and sex/estrous phase. Long Evans rats displayed the greatest sensitivity to GBL, followed by Wistar rats, and then by Sprague-Dawley rats. GBL-evoked SWDs were modulated by estrous cycle in female rats, with the lowest sensitivity to GBL occurring during metestrus. Wistar rats showed the greatest variability as a function of dose, and the least variability within dose; these features make this strain desirable for interventional studies. Moreover, our finding that the SWD response to GBL differs as a function of estrous cycle underscores the importance of cycle monitoring in studies examining female animals using this model. Together, these strain and sex-dependent findings provide guidance for future studies.
Topics: 4-Butyrolactone; Analysis of Variance; Animals; Convulsants; Disease Models, Animal; Dose-Response Relationship, Drug; Electrodes, Implanted; Electroencephalography; Estrous Cycle; Female; Immobility Response, Tonic; Male; Rats; Rats, Long-Evans; Rats, Sprague-Dawley; Rats, Wistar; Seizures; Sex Characteristics; Species Specificity
PubMed: 30261353
DOI: 10.1016/j.eplepsyres.2018.09.007 -
ENeuro 2018Surge release of gonadotropin-releasing hormone (GnRH) is essential in the activation of pituitary gonadal unit at proestrus afternoon preceded by the rise of serum...
Surge release of gonadotropin-releasing hormone (GnRH) is essential in the activation of pituitary gonadal unit at proestrus afternoon preceded by the rise of serum 17β-estradiol (E2) level during positive feedback period. Here, we describe a mechanism of positive estradiol feedback regulation acting directly on GnRH-green fluorescent protein (GFP) neurons of mice. Whole-cell clamp and loose patch recordings revealed that a high physiological dose of estradiol (200 pM), significantly increased firing rate at proestrus afternoon. The mPSC frequency at proestrus afternoon also increased, whereas it decreased at metestrus afternoon and had no effect at proestrus morning. Inhibition of the estrogen receptor β (ERβ), intracellular blockade of the Src kinase and phosphatidylinositol 3 kinase (PI3K) and scavenge of nitric oxide (NO) inside GnRH neurons prevented the facilitatory estradiol effect indicating involvement of the ERβ/Src/PI3K/Akt/nNOS pathway in this fast, direct stimulatory effect. Immunohistochemistry localized soluble guanylate cyclase, the main NO receptor, in both glutamatergic and GABAergic terminals innervating GnRH neurons. Accordingly, estradiol facilitated neurotransmissions to GnRH neurons via both GABA-R and glutamate/AMPA/kainate-R. These results indicate that estradiol acts directly on GnRH neurons via the ERβ/Akt/nNOS pathway at proestrus afternoon generating NO that retrogradely accelerates GABA and glutamate release from the presynaptic terminals contacting GnRH neurons. The newly explored mechanism might contribute to the regulation of the GnRH surge, a fundamental prerequisite of the ovulation.
Topics: Animals; Estradiol; Glutamic Acid; Gonadotropin-Releasing Hormone; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neurons; Nitric Oxide; Proestrus; Signal Transduction; Synaptic Transmission; gamma-Aminobutyric Acid
PubMed: 30079374
DOI: 10.1523/ENEURO.0057-18.2018 -
Journal of Dairy Science Oct 2018The relationship of the estrous cycle to milk composition and milk physical properties was assessed on Holstein (n = 10,696), Brown Swiss (n = 20,501), Simmental (n =...
The relationship of the estrous cycle to milk composition and milk physical properties was assessed on Holstein (n = 10,696), Brown Swiss (n = 20,501), Simmental (n = 17,837), and Alpine Grey (n = 8,595) cows reared in northeastern Italy. The first insemination after calving for each cow was chosen to be the day of estrus and insemination. Test days surrounding the insemination date (from 10 d before to 10 d after the day of the estrus) were selected and categorized in phases relative to estrus as diestrus high-progesterone, proestrus, estrus, metestrus, and diestrus increasing-progesterone phases. Milk components and physical properties were predicted on the basis of Fourier-transform infrared spectra of milk samples and were analyzed using a linear mixed model, which included the random effects of herd, the fixed classification effects of year-month, parity number, breed, estrous cycle phase, day nested within the estrous cycle phase, conception, partial regressions on linear and quadratic effects of days in milk nested within parity number, as well as the interactions between conception outcome with estrous cycle phase and breed with estrous cycle phase. Milk composition, particularly fat, protein, and lactose, showed clear differences among the estrous cycle phases. Fat increased by 0.14% from diestrus high-progesterone to estrous phase, whereas protein concomitantly decreased by 0.03%. Lactose appeared to remain relatively constant over diestrus high-progesterone, rising 1 d before the day of estrus followed by a gradual reduction over the subsequent phases. Specific fatty acids were also affected across the estrous cycle phases: C14:0 and C16:0 decreased (-0.34 and -0.48%) from proestrus to estrus with a concomitant increase in C18:0 and C18:1 cis-9 (0.40 and 0.73%). More general categories of fatty acids showed a similar behavior; that is, unsaturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, trans fatty acids, and long-chain fatty acids increased, whereas the saturated fatty acids, medium-chain fatty acids, and short-chain fatty acids decreased during the estrous phase. Finally, urea, somatic cell score, freezing point, pH, and homogenization index were also affected indicating variation associated with the hormonal and behavioral changes of cows in standing estrus. Hence, the variation in milk profiles of cows showing estrus should potentially be taken into account for precision dairy farming management.
Topics: Animals; Cattle; Estrous Cycle; Fatty Acids; Female; Italy; Lactation; Milk; Pregnancy
PubMed: 30055916
DOI: 10.3168/jds.2018-14480 -
International Journal of Reproductive... May 2018Establishment of a standardized animal endometriosis model is necessary for evaluation of new drug effects and for explaining different ethological aspects of this...
BACKGROUND
Establishment of a standardized animal endometriosis model is necessary for evaluation of new drug effects and for explaining different ethological aspects of this disease. For this purpose, we need a model which has more similarity to human endometriosis.
OBJECTIVE
Our objective was to establish an autologous endometriosis mouse model based on endogenous estrogen level and analyze the influence of estrus cycle on the maintenance of endometriotic lesions.
MATERIALS AND METHODS
In this experimental study, endometriotic lesions were induced in 52 female NMRI mice by suturing uterine tissue samples to the abdominal wall. The transplantation was either performed at proestrus/estrus or at metestrus/diestrus cycles. Urine-soaked beddings from males and also male vasectomized mice were transferred to the cages to synchronize and maintenance of estrus cycle in female mice. The mice were sacrificed after different transplantation periods (2, 4, 6 or 8 wk). The lesions size, macroscopic growth, model success rate, histological and immune-histochemical analyses were assessed at the end.
RESULTS
From a total of 200 tissue samples sutured into the peritoneal cavity, 83 endometriotic lesions were confirmed by histopathology (41.5%). Model success rate for proestrus/estrus mice was 60.7% vs. 79.2% for metestrus/diestrus mice. The endometriotic lesions had similar growth in both groups. Number of caspase-3, Ki67-positive cells and CD31-positive micro vessels were also similar in endometriotic lesions of two groups.
CONCLUSION
If we maintain the endogenous estrogen levels in mice, we can induce endometriosis mouse model in both proestrus/estrus and metestrus/diestrus cycle without any significant difference.
PubMed: 30027146
DOI: No ID Found