Response of Plasma Concentration of Free Amino Acid to Change of Dietary Protein and Amino Acid Levels in Adult Thoroughbreds

Whole-body phenylalanine kinetics and skeletal muscle protein signaling in horses with pituitary pars intermedia dysfunction

“…In the present study, plasma glucose and insulin concentrations 90 minutes after feeding of horses were higher than concentrations before feeding; however, feeding did not result in an increase in plasma concentrations of any indispensable amino acids. Results of another study 25 indicate plasma amino acids reach peak concentrations approximately 90 minutes after feeding of horses; therefore, the lack of detection of a postprandial increase in plasma amino acids concentrations in the present study was unexpected. In the present study, horses consumed 0.86 g of protein/kg during each meal, which was lower than the amount of protein consumed by horses in other studies of mTOR signaling.…”

“…Peak circulating amino acid concentrations in horses are attained 90 to 180 minutes following a meal. 25 Following collection of the blood sample 90 minutes after feeding, a postprandial muscle biopsy sample was obtained from each horse. Horses were lightly sedated with xylazine hydrochloride (0.5 mg/kg, IV [concentration of xylazine, 100 mg/mL]).…”

Nitrogen Retention and Plasma Amino Acid Responses in Mature Geldings Fed Three Dietary Concentrations of Lysine

“…A 1% subsample of urine and 10% subsamples of feces were frozen at À20 C for later analyses. Orts were also collected daily at 6:00 AM, weighed, and frozen at À20 C. Based upon previous studies characterizing plasma AA concentrations in horses after feeding [12,13], blood samples were collected in vacuum tubes on day 11 at 10:00 AM via jugular venipuncture to harvest serum (Corvac serum separator; Tyco Healthcare Group LP, Mansfield, MA) and plasma (Vacutainer lithium heparin; BD, Franklin Lakes, NJ). Plasma collection tubes were stored on ice until centrifuged.…”