Gastric acid secretion and gastrin release in the baboon.
Significant species differences have been demonstrated in gastric physiology, a factor that limits extrapolation of animal data to man. Primate physiology is thought to be similar to that of man; however, gastric function has not been adequately documented in the primate. In the present study six baboons (body weight 25.5 +/- 1.8 kg) were trained to sit in a chair and gastric acid secretion and gastrin release was studied in conscious animals. Mean basal acid secretion was 1.3 +/- 0.1 mmol (H+)/hr. Maximum output after pentagastrin (12 micrograms/kg/hr) was 9.5 +/- 0.9 mmol (H+)/hr and 11.0 +/- 0.4 mmol (H+)/hr after histamine (40 micrograms/kg/hr). A statistically significant (by cosinor analysis) circadian rhythm was demonstrated for intragastric pH over 24 hr in fasted baboons (P less than 0.001). Mean basal serum gastrin level was 37.7 +/- 8.3 pg/ml. The integrated gastrin response after administration of a protein rich meal was 2.52 +/- 0.07 ng x min/ml and this increased to 5.17 +/- 0.18 ng x min/ml (P less than 0.05) following simultaneous administration of a meal with atropine (0.2 mg/kg) (P less than 0.05). Our results suggest that there is significant basal and stimulated acid secretion in the baboon; the amount of acid secreted is similar to that reported in man. Gastric pH demonstrated a circadian rhythm. Postprandial gastrin release was significantly enhanced by cotreatment with atropine. As the present findings are similar to those previously reported in man, the baboon may be a useful model for further studies in gastric physiology and experimental peptic ulceration.
Lakhoo
K
K
Department of Surgery, University of the Witwatersrand, Johannesburg, South Africa.
Parekh
D
D
Lawson
H H
HH
Rogers
G
G
Van der Walt
L A
LA
Hunter
S
S
D000818:Animals; D002940:Circadian Rhythm; D004435:Eating; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005755:Gastrins / Q000378:metabolism*; D006632:Histamine / Q000494:pharmacology; D008297:Male; D010215:Papio; D010418:Pentagastrin / Q000494:pharmacology
D005755:Gastrins; D006632:Histamine; D010418:Pentagastrin