Effects of Ostertagia ostertagi and omeprazole treatment on feed intake and gastrin-related responses in the calf.
Infection with the bovine abomasal nematode, Ostertagia ostertagi, results in a loss of acid-secreting parietal cells and an increase in gastric pH. The effects of an experimental infection with Ostertagia and/or daily treatment with omeprazole (OMP) at 2mgkg(-1) bodyweight for four consecutive days (experiment days 24-27, inclusive) on voluntary feed intake, blood and tissue gastrin concentrations, abomasal G-cell numbers, gastric pH, and blood cholecystokinin (CCK) and pepsinogen concentrations were investigated in the calf. Ostertagia-infected calves demonstrated a significant drop in feed intake between days 24 and 27 post-infection (38%; P<0.001) and in G-cell numbers (42%; P<0.05) and significant increases in abomasal pH (P<0.001), fundic mucosal weight (99%; P<0.01), and blood gastrin (P<0.05) and pepsinogen (P<0.0001). OMP treatment of worm-free animals resulted in a significant drop in intake between days 24 and 27 (30%; P<0.001) and in G-cell numbers (17%; P<0.05) and significant increases in abomasal pH (P<0.01) and blood gastrin (P<0.001). OMP treatment of Ostertagia-infected animals with an existing hypergastrinaemia had no effect on feed intake, abomasal pH, blood gastrin or pepsinogen or abomasal G-cell numbers. Blood CCK concentrations were also unaffected by either Ostertagia infection or OMP treatment. These data suggest that: (a) the depression in feed intake associated with OMP in worm-free calves was not due to a side effect of drug treatment; (b) inappetance in Ostertagia-infected animals is closely associated with the parasite-induced hypergastrinaemia; and (c) the elevation in abomasal pH was a major factor responsible for the elevated blood gastrin concentrations seen in parasitised and OMP-treated animals.
Fox
M T
MT
Department of Veterinary Pathology and Infectious Diseases, The Royal Veterinary College, Royal College Street, London NW1 OUT, UK. mfox@rvc.ac.uk
Uche
U E
UE
Vaillant
C
C
Ganabadi
S
S
Calam
J
J
D000018:Abomasum / Q000469:parasitology / Q000473:pathology; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000378:metabolism / Q000469:parasitology* / Q000473:pathology; D002766:Cholecystokinin / Q000097:blood; D004435:Eating / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005243:Feces / Q000469:parasitology; D005260:Female; D005755:Gastrins / Q000097:blood / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry / Q000662:veterinary; D009853:Omeprazole / Q000494:pharmacology*; D010028:Ostertagia / Q000254:growth & development* / Q000378:metabolism; D010029:Ostertagiasis / Q000097:blood / Q000188:drug therapy / Q000378:metabolism / Q000662:veterinary*; D010270:Parasite Egg Count; D020116:Pepsinogen A / Q000097:blood
D004791:Enzyme Inhibitors; D005755:Gastrins; D020116:Pepsinogen A; D002766:Cholecystokinin; D009853:Omeprazole