Gene Expression of Fresh and Frozen/Thawed Canine Embryos.

BACKGROUND: Canine embryo cryopreservation and subsequent transfer are relevant in the use of reproductive technologies. OBJECTIVE: The purpose of this study is the identification and quantification of the gene expression BAX and Bcl2, AQP3, Na+/K+ ATPase alpha-1 and beta-1 and LIFr in canine embryos obtained in vivo and after freezing. MATERIALS AND METHODS: For the collection of embryos, the bitches were identified at pro-estrous until the detection of 80-90% superficial cells. After that, they were artificially inseminated with fresh semen. The embryos were collected after ovariohysterectomy. RNA was extracted and amplified, and embryos were randomly distributed into fresh (Fr) and frozen/thawed (Ft) groups. RESULTS: Eighteen blastocysts were collected from three bitches. Genes BAX, AQP3 and LIFr did not differ among the studied groups. CONCLUSION: We suggest, through these results, that the genes BAX, Bcl2, AQP3, Na + / K + ATPase alpha-1 and beta-1 and LIFr were expressed in canine blastocysts collected in vivo and after slow freezing cryopreservation.

Concentração de lactato e glicemia em cadelas e neonatos nascidos de cesariana / Lactato concentration in bitch and canine neonates born through cesarean section

Avaliaram-se a concentração de lactato e a glicemia em sete cadelas em trabalho de parto submetidas à cesariana e em seus respectivos neonatos. O lactato materno foi mensurado utilizando-se medidor portátil e pelo método enzimático colorimétrico. Nos neonatos avaliou-se também o peso ao nascimento. Os valores de lactato materno e neonatal foram estatisticamente diferentes, sendo mais elevado nos neonatos. Ao nascimento, as cadelas e os neonatos encontravam-se normoglicêmicos, e não se observou correlação entre a glicemia de ambos. Os valores de lactato obtidos pelo o analisador portátil (3,5±0,6mmol/L) foram mais altos do que os obtidos pelo método enzimático colorimétrico (1,6±0,6mmol/L). Observou-se correlação significativa entre o peso do neonato e a concentração de lactato, isto é, os filhotes de menor peso apresentaram maior concentração de lactato.

This work evaluated the concentration of lactate and blood glucose in seven bitches in labor subject to caesarean section and in their newborns. The lactate concentration was measured using a portable analyzer and enzymatic colorimetric method. In neonates, the birth weight was evaluated. The maternal and neonatal lactate values were statistically different, being higher in newborns. At birth, the bitches and the newborns had normal glucose status, and no correlation was observed between blood glucose in either. The lactate concentration obtained by the portable analyzer (3.5±0.6mmol/L) was higher than that obtained with the enzymatic colorimetric method (1.6±0.6mmol/L). There was significant correlation between the neonate weight and lactate concentration and in puppies with lighter weight there was a higher concentration of lactate.

Ovarian activity reversibility after the use of deslorelin acetate as a short-term contraceptive in domestic queens.

The objective was to evaluate ovarian activity reversibility in domestic queens after short-term contraceptive treatment with deslorelin acetate. Ten mature queens were used. In all queens, the estrous cycle was evaluated every 72 h by vaginal cytology (VC) and behavior assessments. When queens had VC characteristic of interestrus or diestrus, one deslorelin acetate implant (4.7 mg) was placed in the subcutaneous tissue of the interscapular region (day of insertion = Day 0). Thereafter, VC was performed every 48 h and on Day 90, implants were removed. At Day 100, estrus and ovulation were induced with 100 IU eCG (im), followed by 100 IU hCG (im), 84 h later (Day 103.5). Queens were ovariohysterectomized on Day 106. Corpora lutea (CL) were counted, oviducts were flushed, and oocytes were identified, isolated and stained to assess viability. In all queens, blood samples for plasma progesterone concentrations were collected once a week, from Days -21 to 106. After deslorelin acetate application, four queens had VC and behavior typical of estrus, and one ovulated. Furthermore, ovulation occurred in three queens that did not have VC or behavior consistent with estrus. After the initial ovarian stimulation, all females had anestrous VC during the deslorelin treatment period. Implants were readily removed. Following implant removal, all females responded to treatments to induce estrus and ovulation. There were (mean ± SEM) 13.1 ± 5.5 CL and 8.1 ± 5.5 oocytes per queen; the oocyte recovery rate was 56.8 ± 25.4% and all recovered oocytes were viable. We concluded that deslorelin acetate can be used as a reversible short-term contraceptive in domestic cats, because estrus and ovulation were successfully induced following implant removal.

Histological characterization and immunohistochemical localization of ki-67 and VEGF factors in bitches' corpus luteum at cyclic and early and late gestational diestrous.

The luteal phase on pregnant and non-pregnant bitches is characteristic of this species and resembles significantly with respect to the growth pattern and luteal regression. Histological and immunostaining studies of the corpus luteum (CL) may help to elucidate differences between the CL of pregnant and non-pregnant bitches. The purpose of this study was to characterize histologically and localize by immunohistochemistry the cell proliferation (Ki-67) and vascular endothelial growth (VEGF) factors in the CL of pregnant and non-pregnant bitches. Eighteen bitches were analysed and distributed into three groups: In group I (gestational diestrous), seven bitches were subjected to two inseminations at 4 and 6 days after the pre-ovulatory LH surge and ovariohysterectomized (OSH) at 8-21 days after the first insemination. In group II (cyclic diestrous; control), 6 (Ki-67) or 8 (VEGF) bitches that were determined as non-pregnant were OSH at 12-25 days of the pre-ovulatory LH surge. In group III (late pregnancy), three bitches had their ovary removed during caesarean section at 62-64 days after the pre-ovulatory LH surge. Portions of the ovarian cortex containing CLs were cut and stored for histological and immunohistochemical analysis. Histological evaluation of the ovarian cortex showed a marked similarity in the morphological pattern among the CLs in all three groups. The morphology and expression pattern of VEGF and Ki-67 factors in CLs of cyclic and gestational diestrous bitches were similar but significantly lower than that of late pregnant bitches (p < 0.05).

Progesterone (PR), oestrogen (ER-α and ER-ß) and oxytocin (OTR) gene expression in the oviduct and uterus of pregnant and non-pregnant bitches.

The aim was to assess hormone receptor gene expression in the oviduct and uterus during canine pregnancy. Nineteen pregnant bitches divided into four groups were ovariohysterectomized (OVH) at either day 8, 12, 21 or 60 of pregnancy, and five non-pregnant females underwent OVH 12 days after the pre-ovulatory Luteinizant Hormone (LH) surge and served as controls. RT-qPCR for progesterone (PR), oestrogen (ER-α and ER-ß) and oxytocin (OTR) receptors was performed on the oviduct and uterine tissue. The mRNA PR expression in the uterus during early stages of pregnancy and the luteal phase was higher than at other times. The mRNA ER-ß expression in the oviduct during early pregnancy was less than in non-pregnant bitches. In the uterus, the mRNA ER-ß expression was higher in the initial stages of pregnancy. The ER-α expression was higher in the oviduct and uterus in advanced stages of pregnancy. The mRNA OTR expression in the oviduct was lower than in the uterus in control group. The expression of this receptor in oviduct and the uterus was higher in the final stages of pregnancy, when compared with other phases. These data suggested that the serum progesterone concentrations probably exert a direct control on the PR and ER (α and ß) expression and indirectly on OTR expression in the bitch oviduct and uterus.