Stimulation of intestinal apolipoprotein A-IV by lipid is independent of capsaicin-sensitive afferent signals.
We tested the hypothesis that stimulation of synthesis and secretion of intestinal apolipoprotein A-IV (apo A-IV) by intestinally infused lipid is mediated by capsaicin-sensitive afferent signals. Vehicle or capsaicin (125 mg/kg) was systemically administered to rats; then the effects of intestinal infusion of lipid emulsions on lymph lipid and apo A-IV transport were determined in rats equipped with duodenal infusion cannulas and mesenteric lymph fistulas. Capsaicin treatment did not significantly affect lymph outputs of triglyceride, phospholipid, and apo A-IV during duodenal infusion of triglyceride emulsion. In separate studies the effect of capsaicin treatment on ileal lipid-elicited stimulation of intestinal mucosal apo A-IV synthesis was also examined. Ileal lipid infusion increased apo A-IV synthesis in distal ileum, proximal jejunum, and jejunal Thirty-Vella fistulas; this finding was unaffected by capsaicin pretreatment. However, capsaicin treatment significantly attenuated the inhibitory effects of duodenal acid and fat on gastric emptying. These results do not support a role for capsaicin-sensitive, sensory afferent nerves in the stimulation of intestinal apo A-IV by dietary lipid.
Kalogeris
T J
TJ
Department of Surgery, Louisiana State University Medical Center, Shreveport 71130, USA.
Monroe
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F
Tso
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D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001054:Apolipoproteins A / Q000096:biosynthesis / Q000378:metabolism*; D002211:Capsaicin / Q000494:pharmacology*; D004386:Duodenum; D005217:Fat Emulsions, Intravenous / Q000493:pharmacokinetics* / Q000494:pharmacology*; D005230:Fatty Acids, Nonesterified / Q000493:pharmacokinetics; D005402:Fistula; D005746:Gastric Emptying / Q000187:drug effects; D005989:Glycerides / Q000493:pharmacokinetics; D007082:Ileum; D007408:Intestinal Absorption / Q000187:drug effects; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D007583:Jejunum / Q000502:physiology / Q000601:surgery; D008196:Lymph / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014304:Triolein / Q000493:pharmacokinetics
D001054:Apolipoproteins A; D005217:Fat Emulsions, Intravenous; D005230:Fatty Acids, Nonesterified; D005989:Glycerides; C022205:apolipoprotein A-IV; D014304:Triolein; D002211:Capsaicin