Effect of protein intake on gastrin secretion in ruminants

Plasma gastrin concentrations were measured in portal and peripheral circulations in sheep and in cows in response to feeding diets of varying protein content. Mean plasma gastrin concentrations did not increase in response to feeding at either sampling site in contrast with the known response in non-ruminants. Plasma gastrin levels were similar when feeding diets of varying protein content to both sheep and cows and also when comparing portal and peripheral concentrations in sheep. Basal jugular venous gastrin concentrations in the cow at 40.5 +/- 4.13 pg gastrin 17/ml were lower than values measured in sheep portal blood at 67.6 +/- 12.70. The latter, however, was comparable with known values for humans.