Effect of dietary selenite on development and intestinal absorption in offspring rats M.J. Delgado, F. Nogales, M.L. Ojeda, M.L. Murillo, O. Carreras ⁎ Department of Physiology and Zoology, Faculty of Pharmacy, Seville University, 41012 Seville, Spain abstract article info Article history: Received 15 July 2010 Accepted 30 October 2010 Available online 6 November 2010 Keywords: Selenium Intestinal absorption Offspring Deficiency Aim: The present study aims to compare selenium (Se) status in offspring rats born to selenium-deficient and selenium supplemented dams and to analyse Se's influence on intestinal parameters and the intestinal absorption of selenomethionine (Se-Met). Main methods: Male and female Wistar rats (150–200 g) were randomised in: control (C) (0.1 ppm Se), Se- deficient (SD) (0.01 ppm Se) and Se-supplemented (SS) (0.5 ppm Se) groups; and were mated to obtain their offspring. Se levels in serum, urine and faeces in offspring and in mothers' milk were measured by graphite- furnace atomic absorption spectrometry. Duodenal transport studies in offspring were performed using an in vivo perfusion of different Se-Met concentrations (2, 5, 10, 25, 75 and 150 μM). Key finding: A Se-deficient diet provoked a decrease in the offspring's body weight and intestinal parameters, while the supplemented diet increased these values. Serum Se levels were similar between Se-deficient and control offspring because the urinary excretion of Se was smaller to compensate for Se homeostasis. Intestinal Se-Met absorption obeys the Michaellis–Menten equation with lower apparent constant (K m ) and maximal velocity (V max ) in the SD group. However, the C and SS groups presented similar K m and different V max . The V max showed greater values in the following order of rank: SS N C N SD groups. Significance: Selenium intake deficiencies in offspring lead to the development of compensatory mechanisms in order to normalise serum selenium levels. These mechanisms, however, do not permit normal body development; nor do they regulate intestinal parameters and Se-Met transport. © 2010 Elsevier Inc. All rights reserved. Introduction Selenium (Se) is an essential trace element of fundamental importance to human health (Fairweather-Tail et al., in press). It is well known that Se exerts its effects mainly through its incorporation in the selenoproteines such as glutathione peroxidase (GPx), thioredoxin reductases and iodothyronine deiodinase families. Sele- nium is, therefore, a crucial component in several major metabolic pathways, including thyroid hormone metabolism, antioxidant defence systems, immune function and it is also involved in cell growth (Stazi and Trinti, 2008). A deficient and/or low Se status in humans or animals is implicated in a variety of diseases such as endocrine dysfunction. Generally, Se deficiency in adults is caused by an intake of foods low in Se or with low Se availability (Rayman et al., 2008). However, Se deficiency in offspring depends on the concentration and form of the Se in their dams' food. Low selenium levels during gestation and lactation induce oxidative stress in the foetus and impair the development of the neonatal immune system (Pappas et al., 2008). Dietary supplementation with organic or inorganic Se, as seleno- methionine (Se-Met) or selenite respectively, enhanced the growth rate and development of the offspring and it is essential for antioxidant protection and immune function development (Dylewski et al., 2002). Schweizer et al. (2004) described that supplemented inorganic selenium can be transferred efficiently via mother's milk to the developing offspring and Anan et al. (2009) found that Se-Met is a better nutritional source of Se for pups during lactation. But independently of the form ingested, Dorea (2002) reported that Se is present in breast-milk in the form of organic compounds that are well tolerated by breast-fed infants. The intestinal absorption of selenium depends on the Se compounds present in the diet. In general, there is evidence that the transport of inorganic Se-molecules is linear (Vendeland et al., 1992) while organic Se-compound uptake is against a concentration gradient and that it fits with characteristics similar to those for methionine transport (Leblondel et al., 2001). At present, a limited number of studies have explored the uptake of Se in offspring rats (Raghib et al., 1986) or infants (Dorea, 2002; Van Dael et al., 2002). Van Dael et al. (2002) compared the absorption of selenite or selenate in infant formulas, finding a similar impact on the nutritional selenium status of term infants. Intestinal Se transport during growth periods is of interest with regard to of the suitability of supplementary Se in mother's milk. Thereby, the aim of the present study was to compare the development in offspring rats born to Se-deficient and Life Sciences 88 (2011) 150–155 ⁎ Corresponding author. Departamento de Fisiología y Zoología, Facultad de Farmacia, Universidad de Sevilla, C/Tramontana s/n, 41012, Sevilla, Spain. Tel.: +34 954 556 518; fax: +34 954 233 765. E-mail address: olimpia@us.es (O. Carreras). 0024-3205/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.lfs.2010.11.006 Contents lists available at ScienceDirect Life Sciences journal homepage: www.elsevier.com/locate/lifescie