Serum immunoreactive gastrin activity in horses: basal and postprandial values.

Using commercially available diagnostic reagents, serum immunoreactive gastrin activity was measured in five normal horses that were starved of food and water for 24 hours. Blood samples were taken every 15 minutes for two hours. The horses were then fed a pelleted diet for 15 minutes and samples were taken every 15 minutes for a further two hours. Three further samples were taken at hourly intervals. The total sampling period was seven hours. Basal immunoreactive gastrin activity was lower than that reported in other mammals, ranging from a mean of 7.0 pg/ml to 13.8 pg/ml. At 30, 60 and 75 minutes after feeding, mean gastrin immunoreactivity was significantly elevated at 17.4, 19.8 and 18.2 pg/ml respectively. A late significant elevation occurred also five hours after feeding reading 19.4 pg/ml. This low activity may reflect a lower concentration of serum gastrin in the horse than in other mammals, or the methods used in the study may have failed to detect equine serum gastrins.