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Aquaporins have been shown to be regulated by phosphorylation of serine residues, but the possible role of tyrosine residues phosphorylation has not been evaluated. Changes in the localization of aquaporin 2 (AQP2) in the queen endometrium have been related to serum progesterone levels. The aim of this study was to determine whether these AQP2-localization changes are mediated by variations in its tyrosine phosphorylation levels. Twelve queens were included in the study and divided into (a) non-macroscopically pregnant with low levels of progesterone; (b) non-macroscopically pregnant with high levels of progesterone; (c) 30 days of pregnancy; and (d) 60 days of pregnancy. Samples from endometrium and placental transference zone were obtained, immunoprecipitated and analysed by immunoblotting to determine the abundance of AQP2 and its relative levels of tyrosine phosphorylation. No significant differences in the tyrosine phosphorylation levels of immunoprecipated-AQP2 were observed between groups. We can thus conclude that changes in the localization of AQP2 in the queen endometrium are not modulated by tyrosine phosphorylation., (© 2020 Blackwell Verlag GmbH.)

Oestrous suppression by intrauterine devices (IUDs) is caused by prolongation of luteal function, but the biological mechanism is unknown. The aim of the study was to investigate mechanisms which could explain the action of IUDs. Thirty mares were age-matched and either inseminated (AI, n = 15) or fitted with an IUD (IUD, n = 15) and subsequently divided into four groups: AI-P, pregnant (n = 8); AI-N, non-pregnant (n = 7); IUD-P, prolonged luteal phase (n = 7); and IUD-N, normal luteal phase (n = 8). The median ages were 5.5 and 7 years in AI-P and IUD-P groups and 14 and 11 years in AI-N and IUD-N groups, respectively. On Day 15 after ovulation, an endometrial biopsy was obtained to study histomorphological and immunohistochemical expression patterns of uterine proteins (uteroferrin, UF; uterocalin, UC; uteroglobin, UG), oestrogen and progesterone receptors (ER, PR), proliferation marker Ki-67 and content of inflammatory cells. Expression of UF was higher in IUD mares; the difference between pregnant and IUD-P mares was significant. Mares exhibiting a prolonged luteal phase (AI-P, IUD-P) showed only mild angiosclerosis and lower expression of both ER and PR than mares with a normal luteal phase (AI-N, IUD-N). No significant differences were detected in the numbers of inflammatory cells, with the exception of macrophages, which were more numerous in AI-P than AI-N mares. Although inflammatory cells were not detected in IUD mares, increased UF levels may indicate chronic inflammation. Young age and normality of the endometrial blood vessels may improve the efficacy of IUDs., (© 2015 Blackwell Verlag GmbH.)

This short communication describes the case of partial foetal retention in an 18-month-old female French bulldog following induction of abortion owing to an undesired mating. Abortion was induced with aglepristone administered in two consecutive protocols of a dual injection 1 day apart. After failure of the first treatment to achieve abortion, 15 days later, a second treatment was administered. Delivering of aborted foetus occurred 2 days after the last administration. Five weeks after the abortion, the female showed a weak haemorrhagic vaginal discharge. On ultrasound examination, the presence of uterine wall distension as well as a puppy skull inside the uterus was observed. This clinical case makes clear that although aglepristone is a very reliable drug, follow-up of the female during treatment and in the immediate post-partum is necessary to ensure a good outcome., (© 2010 Blackwell Verlag GmbH.)

Seminal plasma (SP) contains several types of compounds derived from the epididymides and accessory glands. The aim of this study was to examine the protein composition of different ejaculate fractions. Trial I: fractionated ejaculates were collected from two normal and two subfertile stallions. Samples containing pre-sperm fluid and the first sperm-rich jets (HIGH-1), the main sperm-rich portion (HIGH-2), the jets with low sperm concentrations (LOW), and a combined whole-ejaculate (WE) sample was centrifuged, and the SP was filtered and frozen. A part of each SP sample was stored (5°C, 24 h) with spermatozoa from HIGH-2 and skim milk extender. Sperm motility was evaluated after storage in extender mixed with the stallion's own SP or SP from one of the other stallions (sperm from a normal stallion stored in SP from a subfertile stallion and vice versa). Protein composition was analysed using reverse-phase liquid chromatography (RP-HPLC), N-terminal sequencing and mass spectrometry. The area-under-the-curve (AUC) was used for quantitative comparison of proteins within fractions. Trial II: semen samples were collected from seven stallions. Fractions with the highest (HIGH) and lowest (LOW) sperm concentrations and WE samples were examined using SDS-PAGE and densitometry. No significant differences emerged between fractions in the AUC-values of the Horse Seminal Protein-1 (HSP-1) and HSP-2 peaks, or the peak containing HSP-3 and HSP-4 (HSP-3/4). Levels of HSP-1, HSP-2 and HSP-3/4 were not significantly correlated with total sperm motility, progressive sperm motility or average path velocity after storage. Significant differences between ejaculate fractions in the amount of different protein groups present in SP were not found in Trial I; but in Trial II, the proteins in the 60-70 kDa range were more abundant in LOW than in HIGH and WE, indicating that this band contained proteins derived mainly from the seminal vesicles, which produce most of the SP in LOW., (© 2010 Blackwell Verlag GmbH.)