Altered luteal expression patterns of genomic and non-genomic progesterone receptors in bitches at different reproductive states

The binding of steroid hormones to their specific receptors is necessary to exert their effects on target cells. Progesterone (P4), a steroid hormone, carries out its effects through both genomic and non-genomic (the cell membrane-associated) receptors. This study aimed to ascertain luteal expression patterns of genomic and non-genomic progesterone receptors in bitches in physiological (early dioestrus and early pregnant) and pathological (pyometra) reproductive states. Luteal tissue was collected from the bitches at early dioestrus (ED, n = 5), early pregnant (EP, n = 5), and pyometra (PY, n = 5). The expression profiles of Steroidogenic Acute Regulator Protein (STAR), Progesterone Receptor (PGR), Membrane Progestin Receptors (PAQR5, PAQR7 and PAQR8), and Progesterone Membrane Components (PGMRC1 and PGMRC2) were examined at the mRNA levels using Real-Time Polymerase Chain Reaction (RT-PCR). Protein levels of PGR, PGMRC1 and PGMRC2 were detected by western blotting (WB). The STAR expression was found in all groups, with a statistical difference observed between EP and PY groups (P < 0.05). The protein level of PGR was determined to be highest in the EP group and lowest in the PY group. The expression of PAQR8 increased in the EP group (P < 0.05). The PAQR5 exhibited high expression in the EP group and low expression in the PY group (P < 0.05). PGRMC1 was more elevated in the EP group and lower in the PY group (P < 0.05). Protein levels of PGMRC1 and PGMRC2 were also observed at the highest expression in EP group. According to the altered expression profiles for examined receptors, we suggest that those progesterone receptors have roles in early pregnancy or pyometra in bitches.

Short-term effect of ovariohysterectomy on urine serotonin, cortisol, testosterone and progesterone in bitches

Objective

This study aimed to investigate the short-term effect of ovariohysterectomy on urine levels of serotonin and its relation to levels of cortisol, testosterone and progesterone in female dogs. Seven bitches were studied before surgical ovariohysterectomy and then once a week during 4 weeks. Spontaneously voided urine samples were collected and concentration ratios of hormone/creatinine in urine were analysed.

Results

The bitches had significantly lower levels of cortisol, testosterone, and progesterone 1 week after ovariohysterectomy compared with before and the levels stayed low throughout the study (P ≤ 0.05). Interestingly, serotonin levels tended to increase 4 weeks after surgery (P = 0.08). A positive correlation between cortisol and progesterone was found before and after surgery. After surgery, serotonin was positively correlated with cortisol and progesterone (P ≤ 0.05).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05680-y.

Genital mycoplasmas of healthy bitches

Little is known about the presence of mycoplasmas in the genital tracts of domestic and stray bitches or in the vaginas of ovariohysterectomized (OHE) bitches. Moreover, to our knowledge, there has been no research to investigate the presence of canine vaginal mycoplasmas during the different stages of the reproductive cycle. We investigated the occurrence of mycoplasmas in the vaginas of healthy domestic and stray intact bitches, to correlate their presence with specific stages of the reproductive cycle, and to compare them with those in OHE bitches. We also investigated the presence of uterine mycoplasmas. Mycoplasmas were isolated from 41 of 122 vaginal swabs (34%) from domestic (27%) and stray (39%) bitches. Mycoplasma canis was the most commonly identified species ( n = 26; 63%), and was detected in both intact (60%) and OHE (73%) bitches. Mycoplasma isolates from the vaginas of healthy bitches did not vary during the various stages of the estrous cycle. Mycoplasmas were not detected in uterine samples.

Serum insulin-like growth factor-1 and C-reactive protein concentrations before and after ovariohysterectomy in bitches with pyometra

Pyometra is one of the most common diseases of the reproductive system in bitches. The inflammatory processes occurring in the uterus result in changes in concentrations of numerous serum biomarkers, which are used for monitoring the postoperative period. The aim of the present report was to study the evolution of serum levels of insulin-like growth factor-1 (IGF-1) and C-reactive protein (CRP) in bitches suffered from pyometra and after ovariohysterectomy in comparison with the control group of healthy dogs submitted to the surgery. Our results indicate that the serum level of IGF-1 is decreased (101.6 ng/mL [73.8-177.8 ng/mL]), whereas CRP is increased (114.6 μg/mL [95.3-131.6 μg/mL]) during severe inflammation. When inflammation caused by pyometra and surgery is resolved, the level of IGF-1 is increased (186.0 ng/mL [94.6-344.3 ng/mL], P < 0.05) and CRP decreased (23.3 μg/mL [9.9-77.0 μg/mL], P < 0.01), suggesting that these markers could be useful for assessment of the postoperative period in bitches.