Acute increase, stimulated by prostaglandin E2, in glucose absorption via the sodium dependent glucose transporter-1 in rat intestine

Abstract

BACKGROUND/AIMSAcute stimulation by cAMP of the sodium dependent glucose cotransporter SGLT1 has previously been shown. As prostaglandin E2(PGE2) increases intracellular cAMP concentrations via its receptor subtypes EP2R and EP4R, it was investigated whether PGE2 could enhance intestinal glucose absorption.METHODSThe action of PGE2 on carbohydrate absorption in the ex situ perfused rat small intestine and on 3-O-[14C]methylglucose uptake in isolated villus tip enterocytes was determined. Expression of mRNA for the PGE2 receptor subtypes 1–4 was assayed in enterocytes by reverse transcriptase polymerase chain reaction (RT-PCR).RESULTSIn the perfused small intestine, PGE2 acutely increased absorption of glucose and galactose, but not fructose (which is not a substrate for SGLT1); in isolated enterocytes it stimulated 3-O-[14C]methylglucose uptake. The 3-O-[14C]methylglucose uptake could be inhibited by the cAMP antagonist RpcAMPS and the specific inhibitor of SGLT1, phlorizin. High levels of EP2R mRNA and EP4R mRNA were detected in villus tip enterocytes.CONCLUSIONPGE2acutely increased glucose and galactose absorption by the small intestine via the SGLT1, with cAMP serving as the second messenger. PGE2 acted directly on the enterocytes, as the stimulation was still observed in isolated enterocytes and RT-PCR detected mRNA for the cAMP-increasing PGE2 receptors EP2R and EP4R.