Biomedical subjects

D R Pascoe

Publications and source records attributed to D R Pascoe.

4 recordsLinked to original sources

PubMed1992

Breed differences in circulating equine relaxin.

Equine relaxin has been previously determined in a small number of pregnant Thoroughbred mares. To better define the normal pregnancy pattern of relaxin, the current study reports on a much larger number of mares. It also was designed to determine if all equids have the same gestational pattern of relaxin secretion. Plasma samples were collected weekly in 24 Standardbred mares, every 7-10 days in 10 pony mares, and daily in late pregnancy from 16 burros. Standardbreds had higher concentrations of relaxin than that reported for Thoroughbreds during most of gestation and did not exhibit the midpregnancy nadir in relaxin concentrations observed in Thoroughbreds. Relaxin concentrations in Standardbreds showed a small but steady decline from Day 150 until delivery. Pony mares had lower relaxin concentrations throughout pregnancy than other mares and had continuously increasing concentrations during gestation. Burros had relaxin concentrations intermediate to ponies and other mares in late gestation. Burros induced to foal with oxytocin showed a sharp increase in relaxin concentrations. No effect of the sex of the offspring was observed in relaxin profiles in Standardbred mares. Each of three Standardbreds with abnormal termination of pregnancy exhibited abnormally low relaxin concentrations at some point in the gestation prior to termination of the pregnancy. Thus, relaxin may be an indicator of placental functioning and used to assess at-risk pregnancies in mares.

Animals↗

PubMed1989

Endogenous prostaglandin F2 alpha release induced by physiologic saline solution infusion in utero in the mare: effect of temperature, osmolarity, and pH.

Thirty mares with normal estrous cycles were allotted equally to 5 groups and infused with 250 ml of saline (NaCl) solution in utero on the seventh day after ovulation to test the effects of temperature, osmolarity, or pH of the saline solution on prostaglandin F2 alpha (PGF2 alpha) release and luteolysis. Intrauterine infusion of phosphate-buffered saline solution failed to alter the duration of the luteal phase, compared with the control group. Similarly, increasing the temperature of phosphate-buffered saline solution to 42 C or increasing (600 mosm) or decreasing osmolarity (less than 10 mosm) did not change the duration of the luteal phase. Decreasing the pH of saline solution to 3 caused significant (P less than 0.0001) releases of PGF2 alpha from the uterus within the first hour after infusion, and the luteal phase was shortened to 8.8 +/- 1.0 days (mean +/- SEM; control, 15 +/- 1.2 days). The results of this study showed that pH is the main factor in eliciting PGF2 alpha release by intrauterine infusion of a saline solution, whereas increased temperature and osmolarity have no effect on the release of PGF2 alpha. The intrauterine infusion of sterile water or physiologic saline (NaCl) solution has been used to induce estrus in mares for the past 50 years. Many investigators have reported that intrauterine infusion of physiologic saline solution or water at body temperature (37 C) or warmer up to 45 C) causes most "anestrous" mares to return to estrus in 1 to 8 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Effect of surgical manipulation, placental fluid, and flunixin meglumine on fetal viability and prostaglandin F2 alpha release in the gravid uterus of mares.

Twenty-one pregnant mares with single or twin conceptuses between 41 and 65 days of gestational age were allotted to 5 treatment groups. A ventral median celiotomy was performed in all mares. In group-1 mares (3 mares, single conceptus), the uterus and fetus were palpated for 5 minutes. In group-2 mares (3 mares, single conceptus, flunixin meglumine), 250 ml of sterile placental fluid was injected into the nongravid uterine horn. In group-3 mares (4 mares, unicornuate twin conceptuses), group-4 mares (3 mares, unicornuate twin conceptuses, flunixin meglumine), and group-5 mares (8 mares, bicornuate twin conceptuses, flunixin meglumine), 1 conceptus was removed from the uterus via hysterotomy. All mares received progesterone prophylactically until day 100 of gestation or until the fetus died. The 3 mares in group 1 delivered clinically normal, live foals. The mean prostaglandin F2 alpha metabolite (PGFM) plasma concentration peaked at 180 +/- 5.2 pg/ml during uterine manipulation and fetal palpation, then declined to baseline by 1 hour. Free placental fluid (group 2) undermined the chorioallantois ventrally and resulted in fetal death within 3 hours after surgery. The mean PGFM plasma concentration peaked at 39 +/- 4 pg/ml following injection of placental fluid. None of the remaining fetuses in the 7 mares with unicornuate twin conceptuses (groups 3 and 4) survived. Five mares with unicornuate twin conceptuses (group 5) delivered single viable foals. In another mare in group 5, the fetus was alive 4 days after surgery, when the mare was euthanatized for a fractured femur.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Induced↗

PubMedDate not supplied

Surgical removal of one conceptus from fifteen mares with twin concepti.

A surgical technique for removal of one conceptus from mares with twin concepti more than 35 days of gestational age was evaluated. One conceptus was removed surgically from each of 15 mares carrying twin concepti that were 41 to 65 days of gestational age. As determined by ultrasonography, eight mares had bicornuate and seven mares had unicornuate twin concepti. For maintenance of pregnancy if surgical trauma should cause prostaglandin release and luteolysis, progesterone was administered prophylactically. Flunixin meglumine was administered perioperatively to minimize prostaglandin release. Five mares with bicornuate twin concepti delivered a single viable foal; in one mare the fetus was alive 4 days after surgery when the mare was euthanatized because of a fractured femur. None of the remaining feti in the seven mares with unicornuate twin concepti survived. The poor survival rate of unicornuate twin concepti was attributed to disruption of the remaining chorioallantois during surgery. Thirteen mares have been rebred successfully.

Abortion, Therapeutic↗