Domestic animal endocrinology最新文献

Circulating microRNAs (miRNAs) are stable in body fluids and can serve as biomarkers for various diseases and physiological states. Although pregnancy˗related miRNAs have been identified in various mammals, studies on parturition˗related circulating miRNAs in mares are limited. Therefore, this study aimed to identify parturition˗related miRNAs and examine their potential applications in the prediction of parturition date. miRNAs were extracted from the plasma of Thoroughbred mares 30 days (295–326 days pregnant) and 5 (323–352 days pregnant) – 0 (328–357 days pregnant) days before parturition, followed by small RNA sequencing (small RNA˗seq) and reverse transcription quantitative PCR (RT˗qPCR). Additionally, we measured plasma progestin concentrations in mares using an enzyme-linked immunosorbent assay. Small RNA˗seq data indicated that 18 miRNAs were affected by parturition proximity. Among the 18 miRNAs, two novel miRNAs and three known miRNAs (miR˗361˗3p, miR˗483, and miR˗99a) showed significant changes at 5–0 days before parturition compared with that at 30 days to parturition. Plasma progestin concentrations were higher at 5–3 days to parturition than at 30 days to parturition, and then decreased on the day of parturition. Conclusively, this study provides basic knowledge of parturition˗related circulating miRNAs in mares, and identifies miRNAs that could potentially be used as biomarkers to predict parturition in mares.

Copper is a vital micronutrient necessary for the maintenance of physiological functions. However, excessive amounts can lead to organ damage. Porcine ovarian granulosa cells are damaged by a high concentration of CuSO₄, which can reduce the reproductive capacity of sows. Quercetin has shown remarkable efficacy in mitigating the harmful effects of heavy metals. Therefore, the aim of this study was to investigate the effects of a high concentration of CuSO₄ on autophagy and apoptosis in porcine ovarian granulosa cells and to explore whether quercetin can counteract these toxic effect. Cell morphology, and the mRNA expression levels of autophagy-related genes (LC3-Ⅰ, ATG5, ATG7, ATG12, Beclin1, mTOR, LC3-Ⅱ and P62) were significantly changed upon treatment with 200 and 400 µM CuSO₄. Treatment with 200 µM CuSO₄ increased expression of P62 protein (P<0.05), promoted LC3-Ⅰ to LC3-Ⅱ conversion (P<0.05), and reduced PINK1 protein expression and the ATP content (P<0.05). In addition, expression of Caspase3 protein was increased and TUNEL staining indicated that the number of apoptotic cells was increased. However, co-treatment with 10 µM quercetin significantly decreased expression of P62 and conversion of LC3-Ⅰ to LC3-Ⅱ. Furthermore, flow cytometric analysis revealed that addition of 10 µM quercetin significantly reduced apoptosis induced by a high concentration of CuSO₄. In summary, the results indicate that a high concentration of CuSO₄ can trigger mitochondrial and autophagy dysfunction, activate mitochondrial apoptosis pathway, and exert cytotoxic effects. Quercetin can mitigate autophagy dysfunction, enhance autophagic processes, and alleviate apoptosis.

Porcine adrenocorticotrophic hormone (ACTH) has been considered valid for the ACTH stimulation test (ACTHST) in humans and dogs; however, its safety and efficacy for use in cats are unknown. Also, the equivalence between 5 µg/kg and 125 µg/cat dose of synthetic corticotropin (1-24 ACTH - cosyntropin/tetracosactide) is assumed for ACTHST in cats. This study evaluated the safety and effectiveness of different porcine recombinant ACTH doses for the ACTHST in healthy cats and its equivalence with tetracosactide. The study was divided into two arms. The first evaluated safety and equivalence of intravenous 1 µg/kg, 5 µg/kg, or 125 µg/cat porcine ACTH in seven healthy cats for the ACTHST evaluating basal and post-ACTH androstenedione, aldosterone, cortisol, and progesterone concentrations. In the second arm, the equivalence of the 125 µg/cat porcine ACTH dose was evaluated compared to results obtained using 125 µg/cat of tetracosactide in ten healthy cats regarding cortisol responses. In all tests, several cat-friendly strategies were adopted, and the ACTHST protocol involved basal and 60-minute post-ACTH blood sampling and intravenous ACTH injection. No adverse reactions were documented, and no tested cat showed any complications during the study. No porcine ACTH tested dose significantly increased androstenedione secretion. In contrast, all tested doses were able to increase progesterone concentration significantly (P < 0.05), and Δ-progesterone in response to 5 µg/kg or 125 µg/cat was considered equivalent (P > 0.99). The 125 µg/cat dose promoted greater responses for both cortisol and aldosterone, characterized by Δ-cortisol (P = 0.009) and Δ-aldosterone (P = 0.004). Despite equivalent Δ-cortisol results in response to 5 µg/kg or 125 µg/cat (P = 0.18); post-ACTH results of cortisol in response to 5 µg/kg only approximate statistical significance when compared with basal (P = 0.07). Porcine ACTH and tetracosactide significantly increased post-ACTH cortisol concentration (P < 0.0001) while the Δ-cortisol was slightly greater in response to the porcine ACTH (P = 0.006). These results suggest porcine ACTH could be an alternative source of corticotropin for the ACTHST in cats; however, maximum corticoadrenal stimulation seemed more reliable in response to a 125 µg/cat regarding cortisol and aldosterone.

Hormonal protocols based on progestogens and equine chorionic gonadotrophin (eCG) are efficient for estrus and ovulation synchronization in ewes. Although eCG is indispensable during seasonal anestrus, it may not be necessary during the breeding season. Thus, we tested the hypothesis that GnRH is effective in replacing eCG during the breeding season allowing satisfactory ovulation rate, luteal function and conception rates after timed artificial insemination (TAI). Ewes (n = 134) with a minimum body condition score of 2.5 (0–5 scale) were treated with intravaginal devices (IVD) containing 60 mg of medroxyprogesterone acetate (MPA) for seven days and received 0.26 mg of sodium cloprostenol at the time of IVD removal. In Exp. 1, at IVD removal, ewes (n = 29) were allocated to three groups: eCG (200 IU at IVD removal; n = 10); eCG+GnRH (200 IU eCG at IVD removal and 4 µg of buserelin 36 h later; n = 10); or GnRH (buserelin 36 h after IVD removal; n = 9). Blood samples were collected 2, 6 and 12 days after TAI moment (54 h after IVD removal), for progesterone (P4) analysis. In Exp 2, the ewes were allocated to eCG (n = 10) or GnRH (n = 10) groups, as above described, and ovulation moment was evaluated 54, 66 and 78 h after IVD removal. In Exp 3, TAI was performed in ewes from eCG (n = 45) and GnRH (n = 40) groups using 100 × 10⁶ motile spermatozoa from a pool of semen collected from four rams. In Exp. 1, based on P4 levels, we confirmed that all the ewes ovulated (29/29) and there was no significant effect of group (P = 0.89) or group x day (P = 0.18) on P4 concentration, being observed a significant effect of day (P = 0.0001). In Exp. 2, the maximum DF diameter (P = 0.26) and ovulation moment (P = 0.69) did not differ between groups. In Exp. 3, pregnancy rate was significantly lower (P = 0.02) in GnRH (22.5 %; 9/40) compared to eCG (46.7 %; 21/45). The results indicate that, although ovulation and luteal function were not altered after eCG, eCG+GnRH or GnRH treatment, GnRH alone before TAI cannot be used to replace eCG treatment during the breeding season.

Nerve growth factor (NGF) has long been known as the main ovulation-inducing factor in induced ovulation species, however, recent studies suggested the NGF role also in those with spontaneous ovulation. The first aim of this study was to evaluate the presence and gene expression of NGF and its cognate receptors, high-affinity neurotrophic tyrosine kinase 1 receptor (NTRK1) and low-affinity p75 nerve growth factor receptor (p75NTR), in the ram genital tract. Moreover, the annual trend of NGF seminal plasma values was investigated to evaluate the possible relationship between the NGF production variations and the ram reproductive seasonality. The presence and expression of the NGF/receptors system was evaluated in the testis, epididymis, vas deferens ampullae, seminal vesicles, prostate, and bulbourethral glands through immunohistochemistry and real-time PCR (qPCR), respectively. Genital tract samples were collected from 5 adult rams, regularly slaughtered at a local abattoir. Semen was collected during the whole year weekly, from 5 different adult rams, reared in a breeding facility, with an artificial vagina. NGF seminal plasma values were assessed through the ELISA method. NGF, NTRK1 and p75NTR immunoreactivity was detected in all male organs examined. NGF-positive immunostaining was observed in the spermatozoa of the germinal epithelium, in the epididymis and the cells of the secretory epithelium of annexed glands, NTRK1 receptor showed a localization pattern like that of NGF, whereas p75NTR immunopositivity was localized in the nerve fibers and ganglia. NGF gene transcript was highest (p < 0.01) in the seminal vesicles and lowest (p < 0.01) in the testis than in the other tissues. NTRK1 gene transcript was highest (p < 0.01) in the seminal vesicles and lowest (p < 0.05) in all the other tissues examined. Gene expression of p75NTR was highest (p < 0.01) in the seminal vesicles and lowest (p < 0.01) in the testis and bulbourethral glands. NGF seminal plasma concentration was greater from January to May (p < 0.01) than in the other months. This study highlighted that the NGF system was expressed in the tissues of all the different genital tracts examined, confirming the role of NGF in ram reproduction. Sheep are short-day breeders, with an anestrus that corresponds to the highest seminal plasma NGF levels, thus suggesting the intriguing idea that this factor could participate in an inhibitory mechanism of male reproductive activity, activated during the female anestrus.

The objective of the study was to characterize the mRNA expression patterns of specific steroid hormone receptors namely, estrogen receptors (ESRRA—estrogen related receptor alpha and ESRRB—estrogen related receptor beta) and progesterone receptors (PGR) in superovulation-induced bovine follicles during the periovulation and subsequent corpus luteum (CL) formation. The bovine ovaries (n = 5 cow / group), containing preovulatory follicles or early CL, were collected relative to injection of the gonadotropin-releasing hormone (GnRH) at (I) 0 h, (II) 4 h, (III) 10 h, (IV) 20 h, (V) 25 h (preovulatory follicles) and (VI) 60 h (CL, 2–3 days after induced ovulation). In this experiment, we analyzed the steroid receptor mRNA expression and their localization in the follicle and CL tissue. The high mRNA expression of ESRRA, ESRRB, and PGR analyzed in the follicles before ovulation is significantly reduced in the group of follicles during ovulation (25 h after GnRH), rising again significantly after ovulation in newly formed CL, only for ESRRA and PGR (P < 0.05). Immunohistochemically, the nuclei of antral follicles' granulosa cells showed a positive staining for ESRRA, followed by higher activity in the large luteal cells just after ovulation (early CL). In contrast, the lower PGR immunopresence in preovulatory follicles increased in both small and large luteal cell nuclei after follicle ovulation. Our results of steroid receptor mRNA expression in this experimentally induced gonadotropin surge provide insight into the molecular mechanisms of the effects of steroid hormones on follicular–luteal tissue in the period close to the ovulation and subsequent CL formation in the cow.

Fescue toxicosis is a syndrome occurring from the consumption of endophyte-infected tall fescue and results in substantial economic losses to the beef industry primarily from reduced growth accompanied by decreased dry matter intake (DMI); however, the associations characterizing this reduction in DMI have yet to be elucidated. The objective of this experiment was to identify endocrine changes associated with intake regulation post-consumption of endophyte-infected tall fescue seed (E+). Twelve Holstein steers were stratified by body weight and assigned to 1 of 3 treatments (n=4): 0 ppm ergovaline (ERV), 1.8 ppm ERV, or 2.7 ppm ERV. Treatments were achieved by combining differing proportions of ground E+ and non-endophyte-infected tall fescue seed. Steers were adapted to their diets for 7 d followed by a 7 d DMI collection period. Within treatment, steers were assigned to a sampling day (d 16 or d 17). Blood samples were collected every 20 min for 8 h, beginning 1 h before feeding. Intake data was analyzed using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) with treatment, day, and the interaction as fixed effects. Hormone and metabolite data were analyzed with the fixed effect of treatment, time, and the interaction including time as a repeated measure and orthogonal contrasts. Dry matter intake was linearly decreased with increasing ERV in the diet (P < 0.001). Insulin and leptin concentrations exhibited a quadratic effect (P = 0.018 and P = 0.005) with insulin concentrations highest for the 2.7 ppm treatment and leptin concentrations highest for the 1.8 ppm treatment. No differences were detected for active ghrelin or β-hydroxybuytrate concentrations among treatment groups. Further, steers consuming both the 1.8 and 2.7 ppm ERV treatments had lower prolactin concentrations compared to the 0 ppm treatment (quadratic, P = 0.019). Glucose concentrations had a tendency for a linear increase as ERV concentrations increased (P = 0.091). A treatment × time interaction (P = 0.002) was noted in NEFA concentrations, with the 1.8 ppm ERV treatment showing increased pre-feeding concentrations, and the 2.7 ppm ERV treatment exhibiting elevated NEFA concentrations as time post-feeding progressed. The results suggest that E+ consumption reduces intake likely through alterations in intake-related hormones and post-absorptive metabolism and contributes to our current understanding of E+ effects on intake reduction while providing avenues for future research.

The activity of the enzyme 11β-hydroxysteroid dehydrogenase type II, which can be estimated by the combined measurement of cortisol and cortisone, is gaining importance as a marker for the assessment of stress in pigs. The aim of this study was to investigate the activity of this enzyme and the salivary concentrations of cortisol and cortisone in pigs during pregnancy, farrowing and lactation and to compare it with other stress-related biomarkers such as CgA, S100A12 and alpha-amylase. Salivary cortisol concentrations and 11β-hydroxysteroid dehydrogenase isoenzyme type 2 activity decreased after farrowing, while cortisol concentrations increased. Enzyme activity did not show significant correlations with any of the other stress-related biomarkers measured in this study. Overall, the results of this report indicate a different regulation of 11β-HSD type II activity and of cortisol and cortisone during pregnancy and lactation, which should be considered when evaluating these analytes in saliva during these periods.

The role of glucagon disturbances in diabetes mellitus is increasingly recognized and, hence, glucagon antagonism might aid in treatment of hyperglycemia and other metabolic disturbances. The aim of this study was to assess the pharmacokinetics of the glucagon receptor antagonist MK-3577 and its effect on plasma glucose, insulin, and glucagon concentrations in healthy cats. In a cross-over placebo-controlled study, 5 purpose-bred cats were treated with either Placebo, MK-3577 (1 mg/kg), or MK-3577 (3 mg/kg). Glucose, insulin and glucagon concentrations were measured at 0, 15, 225, 240 min post-treatment administration. Glucagon (20 mcg/kg, IM) was administered at 240 min and glucose and insulin were measured at 255, 265, 275, 285 and 300 min. Plasma MK-3577 concentrations peaked at 4.2 and 3.2 hours after 1 and 3 mg/kg dosing with a half-life of 14.8h and 15.5h respectively. Baseline glucose, insulin and glucagon concentrations did not differ significantly between treatment groups. At a dose of 3 mg/kg, MK-3577 blunted the glucagon-stimulated rise of glucose (p=0.0089) and insulin (p=0.02). Similar trends were observed with MK-3577 at the 1 mg/kg dose but the effect was smaller, and not significant. In conclusion, the GRA MK-3577 has a pharmacokinetic profile suitable for diminishing the glucagon-induced rise of glucose and insulin in healthy cats.

Fibroblast growth factors (FGFs) are a group of structurally homologous yet functionally pleiotropic proteins. Canonical and intracellular FGFs have primarily autocrine or paracrine effects. However, the FGF19 subfamily, composed of FGF15/19, FGF21, and FGF23, act as endocrine hormones that regulate bile acid, metabolic, and phosphorus homeostasis, respectively. Current research in human and rodent models demonstrates the potential of these endocrine FGFs to target various diseases, including disorders of inherited hypophosphatemia, chronic liver disease, obesity, and insulin resistance. Many diseases targeted for therapeutic use in humans have pathophysiological overlaps in domestic animals. Despite the potential clinical and economic impact, little is known about endocrine FGFs and their signaling pathways in major domestic animal species compared with humans and laboratory animals. This review aims to describe the physiology of these endocrine FGFs, discuss their current therapeutic use, and summarize the contemporary literature regarding endocrine FGFs in domestic animals, focusing on potential future directions.