Summary
Labeled and unlabeled (endogenous) free and phosphorylated thiamine were measured in isolated everted rings of rat jejunumin vitro during short incubation periods (1–10 min). Shortly after the addition of thiamine-14C to the incubation medium, the intracellular specific activity of the free form was higher than the specific activity of the phosphorylated fraction. In the course of time this difference diminished and finally the two specific activities became equal. The conclusion was reached that free thiamine is the likely precursor of intracellular phosphorylated thiamine.
Moreover evidence is presented which indicates that free thiamine entered actively into intestinal epithelial cells. Since free thiamine was modified into phosphorylated form inside the cells, its movement against the endocellular concentration gradient was noticeably favoured.
Similar content being viewed by others
References
Agar, W. T., Hird, F. J. R., Sidhu, G. S.: The uptake of amino acids by the intestine. Biochim. biophys. Acta (Amst.)14, 80–84 (1954)
Burch, H. B., Bessey, O. A., Love, R. H., Lowry, O. H.: The determination of thiamine and thiamine phosphates in small quantities of blood and blood cells. J. biol. Chem.198, 477–490 (1952)
Crane, R. K., Mandelstam, P.: The active transport of sugars by various preparations of hamster intestine. Biochim. biophys. Acta (Amst.)45, 460–476 (1960)
Ferrari, G., Ventura, U., Rindi, G.: The Na+-dependence of thiamine intestinal transportin vitro. Life Sci.10, 67–75 (1971)
Francis, G. E., Mulligan, W., Wormall, A.: Isotopic Tracers. London: University of London, The Athlone Press 1954
Iwashima, A., Nose, Y.: Inhibition of thiamine transport by chloroethylthiamine inEscherichia coli. J. Bact.112, 1438–1440 (1972)
Iwashima, A., Nishino, H., Nose, Y.: Carrier-mediated transport of thiamine in baker's yeast. Biochim. biophys. Acta (Amst.)330, 222–234 (1973)
Kawasaki, T., Miyata, I., Esaki, K., Nose, Y.: Thiamine uptake inEscherichia coli I. General properties of thiamine uptake system inEscherichia coli. Arch. Biochem. Biophys.131, 223–230 (1969)
Kawasaki, T., Yamada, K.: The uptake system of free thiamine in mutants ofEscherichia coli. Biochem. biophys. Res. Commun.47, 465–471 (1972)
Komai, T., Kawai, K., Shindo, H.: Active transport of thiamine from rat small intestine. J. Nutr. Sci. Vitaminol.20, 163–177 (1974)
Komai, T., Shindo, H.: Metabolic fate and mechanism of action of chloroethylthiamine. J. Vitaminol.18, 55–62 (1972)
Krebs, H. A., Henseleit, K.: Untersuchungen über die Harnstoffbildung im Tierkörper. Hoppe-Seylers Z. physiol. Chem.210, 33–66 (1932)
Menon, I. A., Quastel, J. H.: Transport and metabolism of thiamine in Ehrlich ascites-carcinoma cells. Biochem. J.99, 766–775 (1966)
Menon, I. A., Søgnen, E.: Amprolium and transport of thiamine in suspensions of intestinal cells. Acta vet. scand.12, 111–113 (1971)
Neujahr, H. Y.: Transport of B-Vitamins in microorganism I. On the permeability of “Lactobacillus fermenti” to35S-thiamine. Acta chem. scand.17, 1902–1906 (1963)
Neujahr, H. Y.: Transport of B-Vitamins in microorganisms III. Chromatographic studies on the radioactivity extracted from non-proliferating cells ofLactobacillus fermenti after exposure to labelled thiamine. Acta chem. scand.20, 786–798 (1966)
Parsons, D. S.: Mechanisms of intestinal absorption. In: Topics in Gastroenterology 1, Chapter 9, pp. 110–132. Ed. S. C. Truelove and D. P. Jewell. Oxford: Blackwell Scientif. Publ. 1973
Rindi, G., Ventura, U.: Phosphorylation and uphill intestianl transport of thiaminein vitro. Experientia (Basel)23, 175–176 (1967)
Rindi, G., Ventura, U.: Thiamine countertransport in rat small intestine. Pflügers Arch.310, 185–188 (1969)
Rindi, G., Ventura, U.: Thiamine intestinal transport. Physiol. Rev.52, 821–827 (1972)
Sharma, S. K., Quastel, J. H.: Transport and metabolism of thiamine in rat brain cortexin vitro. Biochem. J.94, 790–800 (1965)
Snedecor, G. W., Cochran, W. G.: Statistical methods, 6 ed. Ames, Iowa: The Iowa State University Press 1967
Suzuoki, J.: Thiamine uptake by yeast cells. J. Biochem. (Tokyo)42, 27–39 (1955)
Ventura, U., Ferrari, G., Rindi, G.: Trasporto intestinalein vitro della tiamina: localizzazione asimmetrica della tiaminochinasi nella parete intestinale. Boll. Soc. ital. Biol. sper.45, 1542–1546 (1969a)
Ventura, U., Ferrari, G., Tagliabue, R., Rindi, G.: A kinetical study of thiamine intestinal transportin vitro. Life Sci.8, 699–705 (1969b)
Wilson, T. H., Wiseman, G.: The use of sacs of everted small intestine for the study of the transference of substances from the mucosal to the serosal surface. J. Physiol. (Lond.)123, 116–125 (1954)
Zilversmit, D. B., Entenman, C., Fishler, M. C.: On the calculation ofturnover time andturnover rate from experiments involving the use of labeling agents. J. gen. Physiol.26, 325–331 (1943)
Author information
Authors and Affiliations
Additional information
This work was supported in part by a grant from the Italian Research Council, Rome, Italy.
Rights and permissions
About this article
Cite this article
Ferrari, G., Sciorelli, G., Del Poggio, P. et al. Free thiamine as the likely precursor of endocellular thiamine phosphates in everted rings of rat jejunum. Pflugers Arch. 356, 111–120 (1975). https://doi.org/10.1007/BF00584291
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00584291