QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Garcia-Aranda, J. A. Articles by Lifshitz, F. Search for Related Content PubMed PubMed Citation Articles by Garcia-Aranda, J. A. Articles by Lifshitz, F.

In Vivo Intestinal Absorption of Manganese in the Rat¹

Department of Pediatrics, North Shore University Hospital, Manhasset, NY 11030 ^* Department of Pediatrics, Cornell University Medical College, New York, NY 10021

The mechanisms of intestinal absorption of Mn in rats and the effects of low-molecular-weight ligands in this process were investigated using an in vivo perfusion system. Segments of either jejunum or ileum were perfused with isotonic solutions containing 0.0125 to 0.1 mM MnSO₄ · 7H₂O, in the presence or absence of double its concentration of either L-histidine (His) or citrate (Cit). In all cases the absorption of Mn declined with time; for example, in the absence of ligand Mn absorption fell from (means ± SEM) 16.0 ± 2.2 at 30 minutes to 2.3 ± 4.1 pmol/(minute · cm) after 90 minutes of perfusion. Comparable declines occurred both in the jejunum and in the ileum in the presence of His or Cit. The initial absorption rates of Mn, obtained by extrapolation, were higher in the jejunum when His or Cit were present than when no ligands were included in the perfusate [means ± SD, with His, 66.4 ± 11.9; with Cit, 79.5 ± 6.2; none = 17.8 ± 3.3 pmol/(minute · cm)]. In the ileum, optimum absorption with His was observed between pH 7 and 8. The kinetics of in vivo Mn ileal absorption in the presence of His yielded a K_t of 0.056 mM and an estimated V_max of 158 pmol/(minute · cm). The coefficient of diffusion was calculated to be 1.5 x 10^-3 cm²/minute. These data are compatible with a high affinity, low capacity, active transport mechanism for Mn in the rat intestine and suggest a limited role for small-molecular-weight ligands associated with both diffusional or active translocation processes.

KEY WORDS: • manganese • intestinal absorption • ligands • trace metals

¹ Presented in part at the 67th annual meeting of the Federation of American Societies for Experimental Biology, Chicago, IL, April, 1983. Fed. Proc. 42, 1320, 1983.

² Present address: Hospital Infantil de Mexico, Department of Gastroenterology and Nutrition, Mexico, D.F., Mexico.

³ Correspondence to R. A. W. at first address.

Manuscript received 17 June 1983.

This article has been cited by other articles:

				S. P. Bai, L. Lu, X. G. Luo, and B. Liu Kinetics of Manganese Absorption in Ligated Small Intestinal Segments of Broilers Poult. Sci., December 1, 2008; 87(12): 2596 - 2604. [Abstract] [Full Text] [PDF]

				F. Ji, X. G. Luo, L. Lu, B. Liu, and S. X. Yu Effect of manganese source on manganese absorption by the intestine of broilers. Poult. Sci., November 1, 2006; 85(11): 1947 - 1952. [Abstract] [Full Text] [PDF]