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BMC Veterinary Research Sep 2023Aldosterone represents an important target of heart failure therapy and may be a valuable indicator of the renin-angiotensin-aldosterone system activity. However, its...
BACKGROUND
Aldosterone represents an important target of heart failure therapy and may be a valuable indicator of the renin-angiotensin-aldosterone system activity. However, its assessment might be challenging because of the effect of individual factors. In a recent study, intact female dogs showed the highest value of urinary aldosterone-to-creatinine ratio (UAldo:C) compared to other sex categories. In humans and rodents, an influence of progesterone has been reported by several studies. To our knowledge, the relationship between aldosterone and progesterone has not yet been investigated in dogs. The aim of this prospective study was to investigate this relationship in sexually intact Chihuahua females, measuring both hormones twice in the same bitch, that is in anoestrus when progesterone concentrations are baseline and in dioestrus when they are high.
RESULTS
The study population consisted of 14 sexually intact Chihuahua bitches. Serum progesterone (34.06 (21.17-44.90) vs. 0.19 [0.13-0.38] ng/ml; P < 0.001) and urinary aldosterone (9886.98 ± 5735.22 vs. 5005.72 ± 2127.73 pg/ml; P = 0.01) were significantly higher in dioestrus compared to anoestrous. Urinary aldosterone-to-creatinine ratio was higher in dioestrus compared to anoestrus (4.16 [3.17-6.80] vs. 3.39 ± 1.64 µg/g), but it did not reach the statistical significance (P = 0.056). Serum progesterone showed a moderate positive correlation with urinary aldosterone (ρ = 0.638, P < 0.001) and UAldo:C (ρ = 0.516, P = 0.005).
CONCLUSIONS
The results of the present study suggest the existence of a progesterone-aldosterone relationship in canine species, indicating that sex and phase of reproductive cycle should be taken into account when interpreting aldosterone concentrations. Further studies are needed to confirm these results on a larger canine population and to identify the underlying mechanisms in this species.
Topics: Humans; Animals; Dogs; Female; Aldosterone; Progesterone; Creatinine; Prospective Studies; Diuretics; Anti-Arrhythmia Agents; Cardiotonic Agents
PubMed: 37670293
DOI: 10.1186/s12917-023-03704-2 -
Scientific Reports Nov 2023Despite the prevalent expression of freezing behavior following Pavlovian fear conditioning, a growing body of literature suggests potential sex differences in defensive...
Despite the prevalent expression of freezing behavior following Pavlovian fear conditioning, a growing body of literature suggests potential sex differences in defensive responses. Our study investigated how female defensive behaviors are expressed in different threat situations and modulated by the estrous cycle. We aimed to compare freezing and flight-like responses during the acquisition and retrieval of fear conditioning using two distinct unconditioned stimuli (US) in two different spatial configurations: (1) electrical footshock (FUS) in a small, conventional enclosure with a grid floor, and (2) a predator-like robot (PUS) in a spacious, open arena. Fear conditioning with FUS showed no substantial differences between male and female rats of two different estrous cycles (proestrus and diestrus) in the levels of freezing and flight. However, when PUS was employed, proestrus female rats showed significantly more flight responses to the CS during both acquisition and the retrieval compared to the male and diestrus female rats. Taken together, our findings suggest that hormonal influences on the choice of defensive strategies in threat situations are significantly modulated by both the type of US and the spatial configuration of the environment.
Topics: Rats; Female; Male; Animals; Conditioning, Classical; Estrous Cycle; Fear; Proestrus; Behavior, Animal
PubMed: 38017045
DOI: 10.1038/s41598-023-47591-x -
Animals : An Open Access Journal From... Jun 2020Since in the mare and other animal species such as bitches and cats, the endometrial cell pattern varies depending on the phase of the estrous cycle, the aim of this...
Since in the mare and other animal species such as bitches and cats, the endometrial cell pattern varies depending on the phase of the estrous cycle, the aim of this study was to describe and quantify the endometrial cytological (EC) findings in cycling jennies. EC of eight nonpregnant jennies by cytobrush (CB) at diestrus (day 1 and day 14) and estrous (day 21) were evaluated. All slides were stained with Wright´s stain and microscopically examined at both 400× and 1000× magnification. Seven high-power fields (400×) were assessed in each smear and the endometrial epithelial cells and neutrophils (PMNs) were counted. Endometrial epithelial cells were classified as intact, distorted or fragmented and, on the basis of the presence of dense groups, in monolayer or single clusters. Cytoplasmic characteristics, such as vacuolation or streaming and size, form, position of nuclear characteristics, including karyorrhexis, were recorded. Background aspect, as clear, proteinaceous, or debris, was also considered. In general, sampling by CB provided a yield of cells and clumped endometrial epithelial cells in many smears, being more abundant in estrus than early and late diestrus. Individual endometrial epithelial cells, during estrous, presented a columnar morphology, ciliated or not ciliated and basal nuclei. During diestrus phase, endometrial epithelial cells presented a more cuboidal ciliated or not ciliated morphology. Moderate amount of proteinacious material and red blood cells (RBC) was also observed. Non variation in the percentage of PMNs during diestrus was obtained, but lower and segmented PMNs in CB smears were shown in estrous. This study provides new insights on the physiological changes of endometrial epithelial cells in cycling jennies during the estrus cycle. The CB technique represents a suitable and adequate method for endometrial evaluation, taking into account cytological and/or cytopathological purposes also in jennies.
PubMed: 32575538
DOI: 10.3390/ani10061062 -
Journal of Veterinary Internal Medicine 2010Female Elkhounds are shown to be at increased risk for diabetes mellitus, and occurrence of diabetes during pregnancy has been described in several cases.
BACKGROUND
Female Elkhounds are shown to be at increased risk for diabetes mellitus, and occurrence of diabetes during pregnancy has been described in several cases.
HYPOTHESIS
Onset of diabetes mellitus in Elkhounds is associated with diestrus.
ANIMALS
Sixty-three Elkhounds with diabetes mellitus and 26 healthy controls.
METHODS
Medical records from 63 Elkhounds with diabetes were reviewed and owners were contacted for follow-up information. Blood samples from the day of diagnosis were available for 26 dogs. Glucose, fructosamine, C-peptide, growth hormone (GH), insulin-like growth factor-1, progesterone, and glutamate decarboxylase isoform 65-autoantibodies were analyzed and compared with 26 healthy dogs. Logistic models were used to evaluate the association of clinical variables with the probability of diabetes and with permanent diabetes mellitus after ovariohysterectomy (OHE).
RESULTS
All dogs in the study were intact females and 7 dogs (11%) were pregnant at diagnosis. The 1st clinical signs of diabetes mellitus occurred at a median of 30 days (interquartile range [IQR], 3-45) after estrus, and diagnosis was made at a median of 46 days (IQR, 27-62) after estrus. Diabetes was associated with higher concentrations of GH and lower concentrations of progesterone compared with controls matched for time after estrus. Forty-six percent of dogs that underwent OHE recovered from diabetes with a lower probability of remission in dogs with higher glucose concentrations (odds ratio [OR], 1.2; P=.03) at diagnosis and longer time (weeks) from diagnosis to surgery (OR, 1.5; P=.05).
CONCLUSIONS
Diabetes mellitus in Elkhounds develops mainly during diestrus and pregnancy. Immediate OHE improves the prognosis for remission of diabetes.
Topics: Animals; Case-Control Studies; Diabetes, Gestational; Diestrus; Dog Diseases; Dogs; Female; Logistic Models; Pregnancy; Risk Factors
PubMed: 21054539
DOI: 10.1111/j.1939-1676.2010.0630.x -
Animal Reproduction Science Aug 2023Phoenixin-14 (PNX-14) is a regulatory neuropeptide encoded by the SMIM20 gene, which has been implicated in the reproductive cycle by modulating the...
Phoenixin-14 (PNX-14) is a regulatory neuropeptide encoded by the SMIM20 gene, which has been implicated in the reproductive cycle by modulating the hypothalamic-pituitary-gonadal (HPG) axis. Recently, we showed that PNX-14 is downregulated in bitches with cystic endometrial hyperplasia and pyometra. The objective of this study was to determine the expression of Smim20, PNX-14, and its putative receptor GRP173 in the canine ovary (both healthy and those with ovarian cysts), periovarian adipose tissue (PAT) and in the endometrium during the oestrous cycle. The expression was analysed by RT-qPCR and Western blot. In tissue sections, peptides were localised by immunofluorescent assays, and blood plasma concentrations of PNX-14 were detected by EIA. The results demonstrated increased levels of PNX in bitches in the anestrus groups compared to diestrus animals. The expression of GPR173 increased in PAT during the diestrus phase and endometrial tissue in late diestrus bitches. In the ovary, strong signals of PNX-14 and GPR173 were detected in the luteal and follicular cells. Furthermore, bitches with cystic ovaries were characterised by elevated circulating PNX levels and a significantly higher expression of PNX and GPR173 in gonadal tissues, when compared with healthy animals. Moreover, a positive correlation between PNX and progesterone in the blood of healthy bitches was noted, which changed to a negative correlation in females affected by cystic ovaries. These studies expand the knowledge regarding the expression and localization of the PNX/GRP173 system in canine reproductive organs during physiological and pathological conditions.
Topics: Female; Animals; Dogs; Neuropeptides; Peptides; Endometrial Hyperplasia; Endometrium; Adipose Tissue; Dog Diseases
PubMed: 37356348
DOI: 10.1016/j.anireprosci.2023.107282 -
Heliyon Dec 2022The medial preoptic (MPN) and the ventromedial hypothalamic nuclei (VMN) modulate the estrogen receptor (ER)-dependent female sexual behavior, a response that is...
The medial preoptic (MPN) and the ventromedial hypothalamic nuclei (VMN) modulate the estrogen receptor (ER)-dependent female sexual behavior, a response that is inhibited by tamoxifen (TAM), a modulator of the steroid receptor activation. With the objective to assess TAM action in the brain areas involved in the modulation sexual cues, an animal model on long-term TAM therapy to intact female rats, was used to mimic the 5-year prophylactic TAM therapy offered to women at higher risk of breast cancer. After three months treatment, female sexual behavior with a stud male rat was evaluated. Upon sacrifice, the brains were removed and the MPN and the ventrolateral division of the VMN were screened for the effects of TAM in the expression of ERα, ERβ and progesterone receptor. Results show that TAM inhibited the receptive component of the female sexual behavior. Even though TAM decreased estrogen and progesterone levels to values similar to the ones of estrous and diestrus rats, the biochemical data failed to demonstrate such possible causation for the behavioral response. In fact, TAM administration induced a constant low level of ovarian hormones that changed the pattern of ER and PR expression as well as receptor co-expression in the brain areas regulating the behavioral response, dissimilar to the ones seen in the cycle phases with the same low hormone levels. Nevertheless, present data suggests that by affecting ER- and/or PR-dependent mechanisms, TAM may modulate the hypothalamus, a region known to participate in several social behaviors.
PubMed: 36593822
DOI: 10.1016/j.heliyon.2022.e12362 -
Biology of Reproduction Jul 2021Zearalenone (ZEN), a nonsteroidal estrogenic mycotoxin, is detrimental to female reproduction. Altered chemical biotransformation, depleted primordial follicles and a...
Zearalenone (ZEN), a nonsteroidal estrogenic mycotoxin, is detrimental to female reproduction. Altered chemical biotransformation, depleted primordial follicles and a blunted genotoxicant response have been discovered in obese female ovaries, thus, this study investigated the hypothesis that obesity would enhance ovarian sensitivity to ZEN exposure. Seven-week-old female wild-type nonagouti KK.Cg-a/a mice (lean) and agouti lethal yellow KK.Cg-Ay/J mice (obese) received food and water ad libitum, and either saline or ZEN (40 μg/kg) per os for 15 days. Body and organ weights, and estrous cyclicity were recorded, and ovaries collected posteuthanasia for protein analysis. Body and liver weights were increased (P < 0.05) in the obese mice, but obesity did not affect (P > 0.05) heart, kidney, spleen, uterus, or ovary weight and there was no impact (P > 0.05) of ZEN exposure on body or organ weight in lean or obese mice. Obese mice had shorter proestrus (P < 0.05) and a tendency (P = 0.055) for longer metestrus/diestrus. ZEN exposure in obese mice increased estrus but shortened metestrus/diestrus length. Neither obesity nor ZEN exposure impacted (P > 0.05) circulating progesterone, or ovarian abundance of EPHX1, GSTP1, CYP2E1, ATM, BRCA1, DNMT1, HDAC1, H4K16ac, or H3K9me3. Lean mice exposed to ZEN had a minor increase in γH2AX abundance (P < 0.05). In lean and obese mice, LC-MS/MS identified alterations to proteins involved in chemical metabolism, DNA repair and reproduction. These data identify ZEN-induced adverse ovarian modes of action and suggest that obesity is additive to ZEN-induced ovotoxicity.
Topics: Animals; Estrogens, Non-Steroidal; Female; Mice; Mycotoxins; Ovary; Proteome; Zearalenone
PubMed: 33855340
DOI: 10.1093/biolre/ioab069 -
F&S Science May 2021To establish if the cessation of testosterone (T) therapy reverses T-induced acyclicity in a transgender mouse model that allows for well-defined T cessation timing.
OBJECTIVE
To establish if the cessation of testosterone (T) therapy reverses T-induced acyclicity in a transgender mouse model that allows for well-defined T cessation timing.
DESIGN
Experimental laboratory study using a mouse model.
SETTING
University-based basic science research laboratory.
ANIMALS
A total of 10 C57BL/6NHsd female mice were used in this study.
INTERVENTION(S)
Postpubertal C57BL/6NHsd female mice were subcutaneously implanted with T enanthate (n = 5 mice) or placebo (n = 5 mice) pellets. Pellets were surgically removed after 6 weeks to ensure T cessation, after which the mice were followed for four estrous cycles after the resumption of cyclicity.
MAIN OUTCOME MEASURE(S)
Primary outcomes included daily vaginal cytology and weekly T levels before, during, and after T enanthate or placebo pellet implantation and removal. Secondary outcomes included ovarian follicle distribution and corpora lutea numbers, body metrics, and terminal diestrus hormone levels.
RESULT(S)
T-treated mice (100%) resumed cycling within one week of T pellet removal after six weeks of T therapy. T levels were significantly elevated during T therapy and decreased to control levels after surgical pellet removal. No detectable differences were observed in the follicle count, corpora lutea formation, diestrus hormone levels, or body metrics after four estrous cycles, with the exception of persistent increased clitoral area between T-treated mice and controls. One T-treated mouse was sacrificed early due to vaginal prolapse and not included in subsequent analyses.
CONCLUSION(S)
Our results demonstrated a close temporal relationship between estrous cycle return and T levels dropping to control levels following T pellet removal. The return of regular cyclic ovulatory function is also supported by the formation of corpora lutea and the lack of detectable differences in key reproductive parameters as compared to controls four cycles after T cessation. These results may be relevant to understanding the reversibility of T-induced amenorrhea and possible anovulation in transgender men interested in pausing T to pursue pregnancy or oocyte donation. Results may be limited by the duration of T treatment, lack of functional testing, and physiological differences between mice and humans.
Topics: Animals; Disease Models, Animal; Female; Heptanoates; Mice; Mice, Inbred C57BL; Ovarian Follicle; Pregnancy; Testosterone; Transgender Persons
PubMed: 35559746
DOI: 10.1016/j.xfss.2021.01.008 -
Journal of Veterinary Diagnostic... Jan 2018We investigated the effect of pyometra on kaolin-activated thromboelastography (TEG). Eighteen client-owned dogs with pyometra and 8 healthy spayed dogs were recruited....
We investigated the effect of pyometra on kaolin-activated thromboelastography (TEG). Eighteen client-owned dogs with pyometra and 8 healthy spayed dogs were recruited. TEG parameters and packed cell volume were determined. Results from spayed females and from intact females with pyometra were compared using a Student t-test and Wilcoxon rank sum test. Bitches with pyometra were hypercoagulable compared to spayed bitches as evidenced by elevated maximum amplitude, G, and alpha angle. There were no significant group differences in R time, K time, or clot lysis at 30 or 60 min. Dogs with pyometra should be anticipated to have hypercoagulable TEG variables, and this should be addressed when planning surgical and medical therapy.
Topics: Animals; Dog Diseases; Dogs; Female; Kaolin; Pyometra; Thrombelastography
PubMed: 29059018
DOI: 10.1177/1040638717737349 -
Bio-protocol Sep 2020Endometriosis is a common gynecological disease characterized by the presence of endometrial tissue outside the uterine cavity. It is frequently associated with pain,...
Endometriosis is a common gynecological disease characterized by the presence of endometrial tissue outside the uterine cavity. It is frequently associated with pain, infertility and a reduced quality of life, and it lacks adequate treatment. Several rodent models of endometriosis have been developed through heterologous and homologous transplantation of endometrial tissue into the abdominal compartment. Here we describe a surgical procedure to generate a syngeneic model of endometriosis in immunocompetent mice with intact uterine and ovarian tissues. In this model, four uterine fragments from a donor mouse at diestrus are sutured to the abdominal wall of a recipient mouse. One month after surgeries, endometrial implants develop into cysts with glandular epithelium and stroma, mimicking the endometriotic lesions observed in women with endometriosis. Therefore, this mouse model provides a valuable tool to study the pathophysiology of endometriosis and the efficacy of potential treatments.
PubMed: 33659421
DOI: 10.21769/BioProtoc.3763