title: Central nervous system influence of prostaglandin E2 on jejunal water and electrolyte transport in conscious dogs.
abstract: The effects of intracerebroventricular (i.c.v.) vs. i.v. administration of prostaglandin E2 (PGE2) on net fluxes of water, Na+, and K+ through a jejunal Thiry-Vella loop were investigated before or after previous treatment with adrenergic blockers, indomethacin, and 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB8) in conscious dogs. Administered intracerebroventricularly at doses of 20-100 ng/kg, PGE2 significantly reduced (p less than 0.01), in a dose-related manner, the net fluxes of water, Na+, and K+, which were reversed from an absorption to a secretion. Intravenously administered PGE2 at a five times higher dosage failed to significantly alter net water and electrolyte fluxes. Phentolamine (0.2 mg/kg body wt) and tolazoline (2 mg/kg body wt) administered intravenously abolished the secretory effects of centrally administered PGE2 (50 ng/kg). However, 10 times lower dosages of phentolamine and tolazoline administered intracerebroventricularly did not prevent the PGE2-induced secretion of water and electrolytes. Intracerebroventricular administration of indomethacin (10 micrograms/kg body wt) and TMB8 (1 microgram/kg body wt), did not modify the effect of i.c.v.-administered PGE2; however, indomethacin administered intracerebroventricularly alone stimulated water and electrolyte absorption. None of these treatments results in a significant (p greater than 0.05) change in mean transit time through the Thiry-Vella loop. We conclude that centrally administered PGE2 influences jejunal water, Na+, and K+ absorption, through a mechanism related to adrenergic innervation and/or involving at least alpha 2-adrenoceptors. The results also suggest that PGE2 in the central nervous system controls jejunal water and ion transport in the dog.
authors.forename: M P
authors.initials: MP
authors.lastname: Primi
authors.forename: L
authors.initials: L
authors.lastname: Bueno
mesh_terms: D000818:Animals; D001834:Body Water / Q000378:metabolism*; D002490:Central Nervous System / Q000502:physiology*; D002552:Cerebral Ventricles; D015232:Dinoprostone; D004285:Dogs; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D007262:Infusions, Intravenous; D007263:Infusions, Parenteral; D007583:Jejunum / Q000378:metabolism*; D010646:Phentolamine / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D011458:Prostaglandins E / Q000008:administration & dosage / Q000502:physiology*; D012964:Sodium / Q000378:metabolism*; D014043:Tolazoline / Q000494:pharmacology
chemical_list: D011458:Prostaglandins E; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D012964:Sodium; D014043:Tolazoline; D015232:Dinoprostone; D011188:Potassium; D007213:Indomethacin; D010646:Phentolamine