Intracisternal injection of apolipoprotein A-IV inhibits gastric secretion in pylorus-ligated conscious rats.
OBJECTIVE
Fat feeding increases not only serum but also cerebrospinal fluid concentration of apolipoprotein (apo) A-IV, a protein produced mainly by the small intestine in the rat. We hypothesized that apo A-IV may have a central effect on gastric secretion.


METHODS
Gastric juice was collected by the pylorus ligation method. Rats underwent pylorus ligation and received intracisternal injection of apo A-IV under brief isoflurane anesthesia. Two hours after the injection, gastric juice was collected and gastric acid output determined.


RESULTS
Intracisternal injection of 0.5 microgram apo A-IV had no effect on gastric secretion. However, gastric acid secretion was significantly inhibited by intracisternal injection of 1 microgram apo A-IV. Furthermore, intracisternal administration of higher doses of apo A-IV (2.0 and 4.0 microgram) resulted in greater inhibition of gastric acid secretion in a dose-dependent manner. On the contrary, 4 micrograms of apo A-I intracisternally injected failed to inhibit gastric acid secretion. Intraperitoneal administration of 15 micrograms of apo A-IV did not alter gastric secretion.


CONCLUSIONS
These results suggest that apo A-IV may act in the brain to inhibit gastric acid secretion. Apo A-IV might be a central enterogastrone, which is a gastric inhibitor produced by the small intestine in response to fat feeding.
Department of Surgery, Duke University Medical Center, Durham, North Carolina.
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T
Okumura
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Fukagawa
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Tso
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IL
Taylor
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Pappas
D000818:Animals; D001054:Apolipoproteins A / Q000008:administration & dosage / Q000494:pharmacology*; D002946:Cisterna Magna; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism; D007267:Injections; D007274:Injections, Intraperitoneal; D008026:Ligation; D008297:Male; D011706:Pyloric Antrum; D051381:Rats; D017207:Rats, Sprague-Dawley
D001054:Apolipoproteins A; C022205:apolipoprotein A-IV