9,10 Plasma is the biological fluid into which fluoride must pass for its distribution elsewhere in the body as well as its elimination from the body. For these reasons, plasma is often referred to as the central compartment of the body.6 Factors that include fluoride intake from various sources may affect plasma fluoride levels, and thus fluoride sellekchem content of breast milk. The aim of this pilot study was to determine the fluoride levels of breast milk and plasma of lactating mothers and the correlation between breast milk and plasma fluoride levels in mothers who regularly consume drinking water with low levels of fluoride. MATERIALS AND METHODS One hundred twenty five mothers aged between 20�C30 years old with hospitalized newborns due to icterus neonatorum were included in the study.

Signed consent was obtained from the participants after explanations regarding the study protocol. The human ethic committee of Selcuk University Experimental Research Center (SUDAM) approved this study (Approval No:2004�C034). Besides being otherwise healthy, the primary selection criteria stipulated the absence of fluoride supplement consumption one month before delivery. The participants regularly consumed drinking water from the same city supply which has been previously shown to contain low levels of fluoride (approx. 0.3 ppm).11 The mothers consumed a regular hospital diet. Milk and plasma samples were collected from lactating mothers within 5 to 7 days after delivery. For milk samples, the breast was swabbed with cotton wool and distilled water before milk collection.

The mother was instructed to press the breast gently to facilitate collection of 5 ml of milk into a polyethylene tube. At the same appointment, 5 ml of blood was obtained and transferred into a fluoride-free heparinized polyethylene tube. Thereafter, the plasma was separated from the blood by centrifugation for 3 min at 3500 g. Milk and plasma samples were further stored at ?18��C until analyses. Before fluoride measurements, the samples were thawed at room temperature. To determine fluoride concentrations, equal volumes of TISAB II buffer (Orion Research, U.S.A.) was added into the samples. All samples were homogenized using magnetic stirrers throughout the measurements. An ion-selective electrode (Model 96�C09, Orion Research, USA) was used in conjunction with a Model EA 910 ion analyzer (Orion Research, USA) to measure the fluoride concentrations of the breast milk and plasma samples.

Paired t test was used to determine AV-951 the differences between fluoride concentration of breast milk and plasma. Pearson correlation analysis was used to assess any possible relationship between plasma and breast milk fluoride levels.12 RESULTS The concentrations of fluoride in breast milk and plasma are presented in Table 1. The mean fluoride concentration of the plasma samples was 0.017��0.011 ppm (range 0.006�C0.054 ppm).