Role of prostaglandin E2 in zinc absorption in the rat.

Abstract

The supernatant of cytoplasmic extract of rat small intestine was mixed with 65Zn and subjected to Sephadex G-75 column chromatography. The activity of 65Zn was detected in four peaks with estimated 800, 10,000, 50,000-75,000 mol wt, and larger than 100,000 daltons. The zinc-binding ligand from the 800 mol wt peak was prostaglandin or prostaglandin-like as indicated by ultra-violet absorption spectrum, by absorption spectrum shift in alcoholic potassium hydroxide, by its effects on pulmonary vascular resistance, and by radioimmunoassay. Addition of prostaglandin E2 or prostaglandin extracted from rat small intestine with ethyl acetate into the lumen of intestinal sacs resulted in a two to threefold increase in the activity of 65Zn in the external medium after 15-20 min incubation. The absorption and tissue distribution of orally administered 65Zn were decreased by 60% in indomethacin-treated rats and increased 70% when ethyl acetate-extracted prostaglandin and radioactive zinc were given simultaneously. These data suggest that prostaglandin not only binds zinc, but also facilitates its transport across the intestinal mucosa.

Influence of Picolinic Acid on the Uptake of 65Zinc-Amino Acid Complexes by the Everted Rat Gut

“…Currently there is general agreement among researchers regarding the existence of (a) low molecular weight Zn-binding ligand(s) in human milk, but its(their) identity(ies) remain controversial (Song and Adham, 1978;Cousins and Smith, 1980;Evans, 1980;Hurley and Lonnerdal, 1982;Robello et al, 1982). If the ligand found in milk facilitates Zn absorption, then it is reasonable to expect that presentation of the ligand to intestinal tissue would enhance Zn absorption as well.…”

Plasma and Red Blood Cell Fatty Acid Composition in Children with Protein-Calorie Malnutrition

“…Altered prostaglandins also affect melanocyte function and the formation of edema and could contribute to the changes in pigmentation and edema in kwashiorkor (34,44). Altered prostaglandins might also explain the possible zinc depletion in kwashiorkor because prostaglandin E, assists zinc absorption in rats (37). The role that prostaglandins play in the pathogenesis of kwashiorkor, acrodermatitis enteropathica, and biotin deficiency remains to be determined.…”

Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans

“…The mechanism of its action in facilitating zinc uptake is not fully understood [6], although Johnson and Evans [7] have proposed that the ZBL complex facilitates intestinal transport of zinc and influences transport from plasma to various tissues. Several groups of investigators have suggested various compounds such as picolihate [8,9,10], citrate [11,12,13] and prostaglandins [14] as being the physiologic ZBL. These compounds have all been detected in pancreatic secretions [15].…”