Biomedical subjects

S Acuña

Publications and source records attributed to S Acuña.

4 recordsLinked to original sources

PubMed2005

Experimentally induced subnormal or normal luteal phases in sheep: reproductive hormone profiles and uterine sex steroid receptor expression.

This study investigated if ewes expected to have subnormal luteal phases (SNLP) present a different pattern of uterine oestrogen receptor (ER) and progesterone receptor (PR) expression at the expected time of premature luteolysis. The concentrations of uterine ER, PR and ERalpha mRNA, and the steroid ovarian hormone were determined in anoestrous ewes treated with either gonadotrophin-releasing hormone (GnRH) to develop a SNLP (n = 16), or progesterone + GnRH to develop a normal luteal phase (NLP; n = 16). The ER, PR and ERalpha mRNA concentrations were measured using binding and solution hybridisation assays, while the hormone level concentration was measured by radioimmunoassay. In all ewes, a luteinising hormone- and follicle-stimulating hormone-synchronised surge was found. The SNLP group had lower preovulatory oestradiol levels than the NLP group. On Day 5, the SNLP group had lower progesterone levels, and higher uterine ER, PR and ERalpha mRNA concentrations than the NLP group. While in the SNLP group the receptor expression increased from Days 1 to 5, in the NLP group the receptor expression decreased. The results suggest that the induction of steroid receptor expression in the uterus and the hormonal environment found in the experimental SNLP group at the expected time of premature luteolysis may be involved in the mechanisms causing SNLP.

Animals↗

PubMed2005

Corpus luteum life span and pituitary oestrogen and progesterone receptors in cyclic and gonadotrophin-releasing hormone-treated anoestrous ewes.

The present study investigated the pituitary oestrogen (ER) and progesterone (PR) receptor concentrations in ewes during the oestrous cycle in the breeding season (n = 19), and in anoestrous ewes treated with gonadotrophin-releasing hormone (GnRH) (n = 11) and anoestrous ewes treated with progesterone + GnRH (n = 11). The pituitary ER and PR concentrations at the expected time of ovulation and in the early and late luteal phases were measured by binding assay. The pattern of pituitary ER and PR concentrations in the progesterone + GnRH-treated ewes resembled the pattern found during the normal oestrous cycle, with ER and PR concentrations decreasing from the time of ovulation to the early luteal phase. In contrast, in ewes treated with GnRH alone, ER and PR concentrations increased in the early luteal phase, which may increase the inhibitory effects of steroid hormones on luteinising hormone secretion, ultimately leading to the development of subnormal luteal phases.

Analysis of Variance↗

PubMed2004

Effect of plane of nutrition on endometrial sex steroid receptor expression in ewes.

The effect of plane of nutrition on progesterone receptor (PR) and estrogen receptor alpha (ERalpha) expression in ovine endometrium was investigated. Rasa Aragonesa ewes (n=26) were fed diets to provide either 1.5 (Group C) or 0.5 (Group L) times the daily maintenance requirement and were slaughtered at Days 5 or 10 of the estrous cycle (Day 0=estrus). PR and ERalpha immunoreactivity were analyzed in eight endometrial cell compartments, defined by cell type and location. Group L had less PR immunostaining on Day 5 (P<0.05), which is consistent with lesser endometrial content of progesterone found in such animals. Most cell types of Group C had down regulation of PR at Day 10, but in Group L, this pattern was observed only in three cell compartments. The lesser PR contents found at Day 5 in Group L ewes may explain the lack of inhibition of PR. No effect of treatment or day of the estrous cycle was observed in ERalpha. Results indicate that endometrial PR is affected in a cell type, in specific manner, by plane of nutrition.

Animals↗

PubMed1989

[Prolonged intergenesic period. A high risk factor?].

A prospective study is effected in 115 pregnant patients with an intergenesic period (IGP) of 7 years or more and it is compared with an equal number of patients with a minor IGP to this age. From these patients, 86 (74.8%) do not present pathology and 29 (25.2%) present it. These groups are divided in turn in two categories, from 35 years old to more and minors to this age. Differences are not found in the form of beginning parturition, way of this form of membranes breakage, duration of working of parturition and expellant between both independent groups to the maternal age. The perinatal results are alike except a minor average weight in mothers with prolonged IGP children. The patients with pathology were managed according to this, independent to their IGP. In conclusion only patients with prolonged IGP must be managed as high risk, when they present furthermore associated pathology and those patients with prolonged IGP independent to this duration have raised possibilities of success in vaginal parturition in absence of pathology.

Adult↗