Effects of oxytocin, lipopolysaccharide (LPS), and polyunsaturated fatty acids on prostaglandin secretion and gene expression in equine endometrial explant cultures.

Increased secretion of prostaglandin F(2)α (PGF(2)α) within the uterus because of uterine inflammation can cause luteolysis and result in early embryonic loss. Supplementation with polyunsaturated fatty acids (PUFAs) has been shown to influence PG production in many species, although the effects on the mare remain unknown. The present study aimed to determine fatty acid uptake in equine endometrial explants and evaluate their influence on PG secretion and expression of enzymes involved in PG synthesis in vitro. Equine endometrial explants were treated with 100 µM arachidonic acid, eicosapentaenoic acid, or docosahexaenoic acid and then challenged with oxytocin (250 nM) or lipopolysaccharide (LPS; 1 µg/mL). Production of PGF(2)α and PG E(2) (PGE(2)) was measured, and mRNA expression of enzymes involved in PG synthesis was determined with quantitative real-time PCR. Media concentrations of PGF(2)α and PGE(2) were higher (P < 0.0001) from endometrial explants challenged with oxytocin or LPS compared with controls despite which fatty acid was added. Only DHA lowered (P < 0.0001) media concentrations of PGF(2)α and PGE(2) from explants. Endometrial explants stimulated with oxytocin had increased expression of PG-endoperoxide synthase 1 (PTGS1; P < 0.02), PG-endoperoxide synthase 2 (PTGS2; P < 0.001), PG F(2)α synthase (PGFS; P < 0.01), PG E(2) synthase (PGES; P < 0.01), and phospholipase A(2) (PLA(2); P < 0.005) compared with controls and regardless of fatty acid treatment; whereas stimulation with LPS increased expression of PTGS2 (P < 0.004), PGFS (P < 0.03), PGES (P < 0.01), and PLA(2) (P < 0.01) compared with controls and regardless of fatty acid treatment. Treatment with PUFAs, specifically DHA, can influence PG secretion in vitro through mechanisms other than enzyme expression.

Technical note: equine skeletal preservation techniques to enhance teaching effectiveness.

When the decision was made to euthanatize an acutely laminitic Thoroughbred broodmare, graduate students from the Department of Animal Sciences and Industry reconstructed the skeleton for use as a teaching tool. The reproductive and gastrointestinal tracts were removed and preserved in formalin. The hide, muscle, tendons, ligaments, and organs were removed, and the bones were boiled in water for > or = 48 h to remove all remaining tissue. After boiling, the bones were soaked in gasoline to remove fat from the marrow cavities and then soaked in a bleach/detergent mixture as a final cleaning step. The bones were allowed to dry for several weeks, then a semi-gloss clear lacquer was applied to aid in preservation. The bones were connected with 17-gauge wire and supported by two 1.91-cm galvanized steel rods on a mobile platform. The vertebral column was aligned on flexible copper tube with a 1.27-cm diameter. Additional support was provided for the head and neck by aluminum and steel rods extending from the front support. The final product is a complete, mobile skeleton that will be used as a teaching aid in equine classes. The skeleton serves a function for all levels of the cognitive learning domain. Examples of applications include memorization, identification, and location of bones; use in case studies for synthesis and demonstration of brainstorming efforts; and evaluation of joint ailments for more advanced levels of learning.

Use of different nonglycolysable sugars to maintain stallion sperm viability when frozen or stored at 37 degrees C and 5 degrees C in a bovine serum albumin medium.

Bovine serum albumin (BSA) diluents containing lactose, raffinose or sucrose were not different (P greater than 0.05) in their ability to maintain stallion sperm viability, as determined by percentage motile spermatozoa (PMS) and their rate of forward movement (RFM), when stored at 37 or 5 degrees C for 24 h. These diluents did promote a higher (P greater than 0.05) PMS and RFM, when compared with BSA diluents containing arabinose or galactose. The BSA-arabinose and BSA-galactose diluents did not differ (P less than 0.05) in their ability to support sperm viability and were detrimental to spermatozoa. The fertility of freshly collected and diluted spermatozoa was not different (P greater than 0.05) when extended in BSA diluents containing lactose, raffinose or sucrose. There was no difference (P greater than 0.05) in PMS and RFM of frozen-thawed stallion spermatozoa when the spermatozoa were frozen, thawed and incubated at 37 degrees C for 180 min in BSA diluents containing lactose, raffinose or sucrose. Spermatozoa from 6 of 8 stallions did not survive the freezing process. A one-cycle conception rate of 32% was obtained from frozen-thawed spermatozoa extended in BSA diluents containing lactose, raffinose or sucrose. This rate was 78% of the conception rate obtained when the same mares were inseminated with fresh semen in a subsequent study (41%).