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BMC Veterinary Research Jun 2024The present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via...
AIM
The present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via natural mating, artificial insemination (AI), or intravaginal deposition (vaginal fundus) of different biological fluids or a placebo.
MATERIALS AND METHODS
In a double-blind study, six German Holstein cows were administered PGF during dioestrus and 48 h later treated with GnRH. Intravaginal or intrauterine treatments were carried out 12 h after GnRH was administered. Animals served as their controls, using a cross-over design with an interval of 14 days between experiments. The experimental animals were allocated to receive the following treatments: natural mating (N), intrauterine artificial insemination (A), intravaginal deposition (vaginal fundus) of 6 mL raw semen (R) or 6 mL seminal plasma (S), and compared to their controls [control 1: 6 mL placebo (P: physiological saline); control 2: no treatment (C)). Corresponding time intervals were chosen for the untreated control oestrus. Blood flow volume (BFV) in the uterine (u) and vaginal (v) arteries ipsilateral to the ovary bearing the preovulatory follicle was determined using transrectal Doppler sonography.
RESULTS
All animals exhibited oestrus and ovulated between 30 and 36 h after GnRH. Transient increases (P < 0.05) in vaginal blood flow occurred between 3 and 12 h following mating as well as 3 to 9 h after deposition of raw semen and seminal plasma, respectively. The most distinct increases (199%) in vBFV occurred 6 h after mating compared to values immediately before mating (= time 0 h). Neither AI nor deposition of a placebo into the vagina affected vBFV (P > 0.05). Only mating and deposition of either raw semen, seminal plasma or AI increased uBFV (P < 0.003). The greatest rise in uBFV occurred after natural mating. Maximum uBFV values were detected 9 h after mating when values were 79% greater (P < 0.05) than at 0 h.
CONCLUSIONS
The natural mating, deposition of raw semen or seminal plasma and conventional AI affect vaginal and/or uterine blood flow to different degrees. The factors responsible for these alterations in blood flow and their effects on fertility remain to be clarified in future studies.
Topics: Animals; Insemination, Artificial; Female; Semen; Cattle; Vagina; Uterus; Male; Administration, Intravaginal; Double-Blind Method; Gonadotropin-Releasing Hormone; Cross-Over Studies; Regional Blood Flow
PubMed: 38926710
DOI: 10.1186/s12917-024-03919-x -
Reproduction in Domestic Animals =... Jun 2024Understanding the normal physiology of the canine mammary gland (CMG) is crucial, as it provides a foundational reference for understanding canine mammary neoplasms. The...
Understanding the normal physiology of the canine mammary gland (CMG) is crucial, as it provides a foundational reference for understanding canine mammary neoplasms. The relation between the Proliferation Index (PI) indicated by Ki-67 expression, along with the Apoptotic Index (AI) determined through Caspase-3 expression during the oestrous cycle, is inadequately documented in existing literature. This study seeks to offer insights into the interplay between PI and AI in the CMG across oestrous cycle phases. An extensive investigation was conducted on a diverse case series of bitches (n = 18). Oestrous cycle stages were determined through vaginal cytology, histological examination of the reproductive tract and serum progesterone and oestradiol concentrations. The entire mammary chain was histologically examined, and proliferation and apoptosis were assessed via double immunohistochemistry employing anti-Ki-67 and Caspase-3 antibodies. PI and AI were evaluated through a systematic random sampling approach, counting a minimum of 200 cells for each cell type. There was a significantly higher PI during early dioestrus in all mammary gland components, with a greater proportion of positive cells observed in epithelial cells compared to stromal cells. The highest PI was detected in epithelial cells within the end buds. Significant differences were found in Ki-67 labelling across the cranial mammary glands. A positive and strong correlation was noted between progesterone concentration and PI in epithelial cells. The AI remained consistently low throughout the oestrous cycle, with few differences observed across histological components. Caspase-3 labelling displayed the highest positivity in caudal mammary pairs. A negative and moderate correlation was identified between progesterone concentration and AI in interlobular mesenchymal cells. This study highlights the influence of endocrine regulation on cell proliferation indices in mammary tissue, emphasizing the need to consider these hormonal variations in toxicopathological studies involving canine mammary gland.
Topics: Animals; Female; Ki-67 Antigen; Dogs; Apoptosis; Mammary Glands, Animal; Caspase 3; Cell Proliferation; Estrous Cycle; Progesterone; Estradiol; Epithelial Cells
PubMed: 38924202
DOI: 10.1111/rda.14655 -
Biology of Reproduction Jun 2024In cattle, the endometrium during diestrus and early pregnancy displays cellular responses that are consequences of prior, transient stimuli. Goal was to establish a...
In cattle, the endometrium during diestrus and early pregnancy displays cellular responses that are consequences of prior, transient stimuli. Goal was to establish a model to study cellular memory in the endometrium. The hypothesis is that stimuli given to endometrium in vivo are retained as a cellular memory that remains after bovine uterine epithelial cells (BUECs) are isolated, cultured, and further stimulated in vitro. Objectives were to measure BUEC proliferation/migration and responsiveness to recombinant bovine Interferon-tau (rbIFNT) in vitro: among cows that showed estrus (experiment 1 [Exp1]), cows that became or not pregnant to artificial insemination (Exp2), cows that received or not supplemental progesterone (P4; Exp3) and cows that received or not a COX-1/2 inhibitor (Exp4). Only cows that displayed estrus were included in studies. For all experiments endometrial cytology was collected 4 days after estrus, BUECs were cultured, propagated, and submitted to rbIFNT treatment and an in vitro scratch assay. In Exp1, different cows spontaneously grouped according to proliferative/migratory capacity and responsiveness to rbIFNT of their respective BUECs. In Exp2, BUECs from pregnant cows showed greater rbIFNT responsiveness and cellular proliferation. In Exp3, BUECs from cows supplemented with P4 presented inhibited proliferation and increased expression of RSAD2. In Exp4, Flunixin Meglumine modified rbIFNT responsiveness of BUECs in an IFN-signaling pathway-specific manner. In conclusion, physiological and pharmacological stimuli received by the endometrium in vivo were retained as cellular memory in BUECs, persisted in culture, and changed BUEC proliferation/migration and responsiveness to rbIFNT, which are characteristics associated with fertility in cattle.
PubMed: 38910516
DOI: 10.1093/biolre/ioae093 -
Reproduction in Domestic Animals =... Jun 2024This study evaluated whether the treatment of pseudopregnancy in bitches with vitamin B6 modulates uterine expression of receptors for progesterone (PR), oestrogen...
This study evaluated whether the treatment of pseudopregnancy in bitches with vitamin B6 modulates uterine expression of receptors for progesterone (PR), oestrogen (ERα), androgen (AR), thyroid hormone (TRα) and the kisspeptin/Kiss1r system. Eighteen pseudopregnant bitches were treated for 20 days in groups receiving placebo (n = 6); cabergoline (5 μg/kg/day; n = 6); or vitamin B6 (50 mg/kg/day; n = 6). Blood was collected on the 1st day of drug administration and 120 h later to measure serum prolactin (PRL). After treatment, they were ovariohysterectomized and uterine fragments were collected for histomorphometry and immunohistochemical evaluation of PR, ERα, AR, TRα, Kiss1 and Kiss1r. After 120 h of cabergoline or vitamin B6 treatment, PRL levels were reduced in the bitches, confirming the antiprolactinemic effect of these drugs. Furthermore, regardless of treatment, the animals exhibited uterine histomorphometry consistent with dioestrus. The PR showed strong immunostaining in all regions and an increase in scores was observed for this receptor in animals treated with vitamin B6 in deep glands. In contrast, ERα and Kiss1R receptors showed weak to no immunostaining in all uterine regions and no changes between groups. Regarding AR, most animals treated with vitamin B6 showed increased trends in the deep gland and myometrium marking scores. In contrast, in both vitamin B6 and cabergoline treatments, a reduction in TRα marking scores was observed compared to the control group. In addition, on the endometrial surface, a reduction was observed in the marked area of Kiss1 after administration of cabergoline when compared to the pseudopregnant control group. These findings shed valuable insight into the use of vitamin B6 as a drug with actions similar to cabergoline in reducing PRL and uterine modulation in bitches.
Topics: Animals; Female; Dogs; Kisspeptins; Uterus; Cabergoline; Prolactin; Pseudopregnancy; Receptors, Progesterone; Receptors, Androgen; Ergolines
PubMed: 38847348
DOI: 10.1111/rda.14630 -
BioRxiv : the Preprint Server For... May 2024Many neuropsychiatric disorders show sex differences in prevalence and presentation. For example, Tourette's Syndrome (TS) is diagnosed 3-5 times more often in males....
BACKGROUND
Many neuropsychiatric disorders show sex differences in prevalence and presentation. For example, Tourette's Syndrome (TS) is diagnosed 3-5 times more often in males. Dopamine modulation of the basal ganglia is implicated in numerous neuropsychiatric conditions, including TS. Motivated by an unexpected genetic finding in a family with TS, we previously characterized the modulation of striatal dopamine by histamine.
METHODS
We used microdialysis to analyze striatal dopamine response to the targeted infusion of histamine and histamine agonists. siRNA knockdown of histamine receptors was used to identify the cellular mediators of observed effects.
RESULTS
Intracerebroventricular histamine reduced striatal dopamine in male mice, replicating previous work. Unexpectedly, histamine increased striatal dopamine in females. Targeted infusion of selected agonists revealed that the effect in males depends on H2R receptors in the substantia nigra pars compacta (SNc). Knockdown of H2R in SNc GABAergic neurons abrogated the effect, identifying these cells as a key locus of histamine's regulation of dopamine in males. In females, in contrast, H2R had no role; instead, H3R agonists in the striatum increased striatal dopamine. Strikingly, the effect of histamine on dopamine in females was modulated by the estrous cycle, appearing in estrus/proestrus but not in metestrus/diestrus.
CONCLUSIONS
These findings confirm the regulation of striatal dopamine by histamine but identify marked sexual dimorphism in and estrous modulation of this effect. These findings may shed light on the mechanistic underpinnings of other sex differences in the striatal circuitry, perhaps including the marked sex differences seen in TS and related neuropsychiatric conditions.
PubMed: 38826392
DOI: 10.1101/2024.05.20.595049 -
Journal of Neuroendocrinology Jun 2024Reproduction in all mammalian species depends on the growth and maturation of ovarian follicles, that is, folliculogenesis. Follicular development can culminate with the...
Reproduction in all mammalian species depends on the growth and maturation of ovarian follicles, that is, folliculogenesis. Follicular development can culminate with the rupture of mature follicles and the consequent expulsion of their oocytes (ovulation) or in atresia, characterized by the arrest of development and eventual degeneration. These processes are regulated by different neuroendocrine signals arising at different hypothalamic nuclei, including the suprachiasmatic nucleus (SCN). In the later, the activation of muscarinic receptors (mAChRs) and nicotinic receptors (nAChRs) by acetylcholine is essential for the regulation of the pre-ovulatory signals that stimulate the rupture of mature follicles. To evaluate the participation of the nAChRs in the SCN throughout the oestrous cycle in the regulation of the hypothalamic-pituitary-ovarian axis. For this purpose, 90-day-old adult female rats in metoestrus, dioestrus, proestrus or oestrus were microinjected into the left- or right-SCN with 0.3 μL of saline solution as vehicle or with 0.225 μg of mecamylamine (Mec), a non-selective antagonist of the nicotinic receptors, diluted in 0.3 μL of vehicle. The animals were sacrificed when they presented vaginal cornification, indicative of oestrus stage, and the effects of the unilateral pharmacological blockade of the nAChRs in the SCN on follicular development, ovulation and secretion of oestradiol and follicle-stimulating hormone (FSH) were evaluated. The microinjection of Mec decreased the serum levels of FSH, which resulted in a lower number of growing and healthy follicles and an increase in atresia. The higher percentage of atresia in pre-ovulatory follicles was related to a decrease in the number of ova shed and abnormalities in oestradiol secretion. We also detected asymmetric responses between the left and right treatments that depended on the stage of the oestrous cycle. The present results allow us to suggest that during all the stages of the oestrous cycle, cholinergic signals that act on the nAChRs in the SCN are pivotal to modulate the secretion of gonadotropins and hence the physiology of the ovaries. Further research is needed to determine if such signals are generated by the cholinergic neurons in the SCN or by cholinergic afferents to the SCN.
PubMed: 38826071
DOI: 10.1111/jne.13421 -
Scientific Reports May 2024Sex hormones affect structural and functional plasticity in the rodent hippocampus. However, hormone levels not only differ between males and females, but also fluctuate...
Sex hormones affect structural and functional plasticity in the rodent hippocampus. However, hormone levels not only differ between males and females, but also fluctuate across the female estrous cycle. While sex- and cycle-dependent differences in dendritic spine density and morphology have been found in the rodent CA1 region, but not in the CA3 or the dentate gyrus, comparable structural data on CA2, i.e. the hippocampal region involved in social recognition memory, is so far lacking. In this study, we, therefore, used wildtype male and female mice in diestrus or proestrus to analyze spines on dendritic segments from identified CA2 neurons. In basal stratum oriens, we found no differences in spine density, but a significant shift towards larger spine head areas in male mice compared to females. Conversely, in apical stratum radiatum diestrus females had a significantly higher spine density, and females in either cycle stage had a significant shift towards larger spine head areas as compared to males, with diestrus females showing the larger shift. Our results provide further evidence for the sexual dimorphism of hippocampal area CA2, and underscore the importance of considering not only the sex, but also the stage of the estrous cycle when interpreting morphological data.
Topics: Animals; Male; Female; Dendritic Spines; Mice; Estrous Cycle; CA2 Region, Hippocampal; Sex Characteristics; Neurons
PubMed: 38806649
DOI: 10.1038/s41598-024-62951-x -
International Journal of Molecular... May 2024Congenital Adrenal Hyperplasia (CAH) is an autosomal recessive disorder impairing cortisol synthesis due to reduced enzymatic activity. This leads to persistent...
Congenital Adrenal Hyperplasia (CAH) is an autosomal recessive disorder impairing cortisol synthesis due to reduced enzymatic activity. This leads to persistent adrenocortical overstimulation and the accumulation of precursors before the blocked enzymatic step. The predominant form of CAH arises from mutations in , causing 21-hydroxylase deficiency (21-OHD). Despite emerging treatment options for CAH, it is not always possible to physiologically replace cortisol levels and counteract hyperandrogenism. Moreover, there is a notable absence of an effective in vivo model for pre-clinical testing. In this work, we developed an animal model for CAH with the clinically relevant point mutation p.R484Q in the previously humanized mouse strain. Mutant mice showed hyperplastic adrenals and exhibited reduced levels of corticosterone and 11-deoxycorticosterone and an increase in progesterone. Female mutants presented with higher aldosterone concentrations, but blood pressure remained similar between wildtype and mutant mice in both sexes. Male mutant mice have normal fertility with a typical testicular appearance, whereas female mutants are infertile, exhibit an abnormal ovarian structure, and remain in a consistent diestrus phase. Conclusively, we show that the animal model has the potential to contribute to testing new treatment options and to prevent comorbidities that result from hormone-related derangements and treatment-related side effects in CAH patients.
Topics: Animals; Adrenal Hyperplasia, Congenital; Disease Models, Animal; Steroid 21-Hydroxylase; Mice; Female; Male; Humans; Corticosterone; Aldosterone; Adrenal Glands; Mutation; Progesterone
PubMed: 38791102
DOI: 10.3390/ijms25105062 -
Genes May 2024Insulin receptor signaling promotes cell differentiation, proliferation, and growth which are essential for oocyte maturation, embryo implantation, endometrial...
Insulin receptor signaling promotes cell differentiation, proliferation, and growth which are essential for oocyte maturation, embryo implantation, endometrial decidualization, and placentation. The dysregulation of insulin signaling in women with metabolic syndromes including diabetes exhibits poor pregnancy outcomes that are poorly understood. We utilized the Cre/LoxP system to target the tissue-specific conditional ablation of insulin receptor () and insulin-like growth factor-1 receptor () using an anti-Mullerian hormone receptor 2 () Cre-driver which is active in ovarian granulosa and uterine stromal cells. Our long-term goal is to examine insulin-dependent molecular mechanisms that underlie diabetic pregnancy complications, and our conditional knockout models allow for such investigation without confounding effects of ligand identity, source and cross-reactivity, or global metabolic status within dams. Puberty occurred with normal timing in all conditional knockout models. Estrous cycles progressed normally in females but were briefly stalled in diestrus in and double receptor (DKO) mice. The expression of vital ovulatory genes (, , ) was not significantly different in 12 h post-hCG superovulated ovaries in knockout mice. Antral follicles exhibited an elevated apoptosis of granulosa cells in and DKO mice. However, the distribution of ovarian follicle subtypes and subsequent ovulations was normal in all insulin receptor mutants compared to littermate controls. While ovulation was normal, all knockout lines were subfertile suggesting that the loss of insulin receptor signaling in the uterine stroma elicits implantation and decidualization defects responsible for subfertility in -Cre-derived insulin receptor mutants.
Topics: Animals; Female; Receptor, Insulin; Receptor, IGF Type 1; Mice; Ovary; Mice, Knockout; Infertility, Female; Ovulation; Granulosa Cells; Pregnancy; Signal Transduction
PubMed: 38790245
DOI: 10.3390/genes15050616 -
Animal Reproduction 2024As a positional and geometrical isomer of linoleic acid, trans 10, cis 12 conjugated linoleic acid (t10c12-CLA) reduces white fat by reducing food intake, modulating...
As a positional and geometrical isomer of linoleic acid, trans 10, cis 12 conjugated linoleic acid (t10c12-CLA) reduces white fat by reducing food intake, modulating lipid metabolism, and stimulating energy expenditure. However, the t10c12-CLA products are mostly mixtures, making it difficult to obtain accurate results. Studies are needed to investigate the effects of pure t10c12-CLA on animals and humans. In this study, we used the biallelic transgenic (tg) mice, which could produce t10c12-CLA itself, to investigate the effects of pure t10c12-CLA on female reproductive ability. The results showed that the body and relative ovary weights had no significant difference between tg and wild-type (wt) littermates at ages 3 or 10 weeks. While the fecundity test found that tg mice had a significantly longer first litter time (32.0 ± 4.70 days vs. 21.3 ± 2.31 days, <0.05), and a significantly lower number of litters (4.75 ± 2.75 vs. 6.67 ± 0.57, <0.05) when compared with wt mice during continuous mating within seven months. Hormone profiles showed that serum estradiol levels did not change in tg mice; however, significantly (<0.05) decreased progesterone and increased prostaglandin E2 levels were observed in tg mice compared with those of wt mice. Hematoxylin-eosin staining showed no pathological characteristics in tg ovaries, except for the increased atresia follicles (<0.05). Moreover, the tg mice had a significantly more extended diestrus period than the wt mice (48.4 ± 6.38% vs. 39.6 ± 3.81%, <0.05). In summary, t10c12-CLA could affect serum progesterone and prostaglandin E2 levels, lead to a disordered estrus cycle, and impact the reproductive performance of female mice. This study provided theoretical and biosafety recommendations for applying t10c12-CLA in female mammals.
PubMed: 38756621
DOI: 10.1590/1984-3143-AR2024-0010