2016 ACVIM Forum Research Abstract Program

In conclusion, for horses deficient in a-TP, the fastest and highest increase in serum a-TP was obtained using water-dispersible RRR-a-TP. A regimen of RRR-a-TP water-dispersible product, tapered to RRR-a-TP acetate, provided an effective means to rapidly and sustainably increase a-TP in serum and CSF over an eight-week period. Equine metabolic syndrome is characterized by regional adiposity, insulin resistance, predisposition to laminitis, and activated inflammation. Regional adiposity in horses is characterized by subcutaneous fat deposits at the nuchal ligament, behind the shoulder, and at the tail head, and increased neck circumference is associated with insulin resistance. In humans and mice, visceral fat is associated with insulin resistance and development of diabetes, and is more metabolically active than other fat depots. In contrast, candidate gene expression studies in horses have suggested that nuchal fat may be more metabolically active than visceral fat. We have collected samples from six adipose tissue depots within the horse; nuchal, shoulder, tail head, (subcutaneous, SQ) and visceral, omental, and retroperitoneal (internal) in six horses of varying age, breed, and sex. To quantify the differences in gene expression in the various depots, an average of 19,085,946 paired-end RNA sequencing reads per sample were generated on the Illumina HiSeq platform. Limma-voom and linear modeling identified 4,252 genes that were differentially expressed between SQ and internal adipose tissue depots. Interestingly, several pathways, including PPAR and PTEN, associated with metabolically active beige/brown fat were highly expressed in SQ compared to internal fat depots. Further, SHOX2 (P = 1.54E-10), a marker for beige fat whose subcutaneous expression levels are also positively correlated with central obesity in humans, was overexpressed in SQ. TBX15 (P = 4.72E-8) and ZIC1 (P = 5.03E-5), genes expressed in brown adipose tissue, were also overexpressed in subcutaneous tissue. Several differences in SQ gene expression were driven by differences in the nuchal fat. There are multiple clinical applications for the acidification of equine urine, including prevention of reoccurrence of urolithiasis. This study evaluated the efficacy of a commercial anionic supplement (SoyChlorÒ) for urinary acidification without altering systemic pH. Eight horses were administered SoyChlorÒ to achieve a DCAD of 0 mEq/kg or À40 mEq/kg or fed a control diet for 14 days in a randomized crossover trial. Urine and plasma pH, plasma strong ion difference, plasma anion gap and fractional excretion of calcium were measured and compared between treatment groups. Mean urine pH across each collection period was significantly greater in control horses compared to either treatment group but there was no difference between treatment groups. Blood pH and anion gap were not affected by treatment, but blood pH decreased and anion gap increased over time. Mean bicarbonate concentration was lower in the 0 mEq/kg group than the control group, but did not differ between the 0 mEq and À40 mEq/kg treatments. Strong ion difference of the 0 mEq treatment was lower than the control group. The mean fractional excretion of calcium over all time points did not differ between treatment groups but there was an effect of time and treatment. Both treatment groups had increased fractional excretion of calcium relative to the control group at trial day 7 only. This study shows SoyChlor supplem