Traditional tea drinking in Senegal. A real source of fluoride intake for the population.

Tea drinking after meals is a traditional practice in Senegal where more than 80% of the population from 15 to 60 years old drink tea. According to the tradition, in one session, each tea consumer has to drink 3 cups of decocted tea. The content of a cup is about 30 ml of liquid. Some people drink tea three times daily, that is to say after each meal. Tea plant is rich in fluoride. To determine the effective intake of the Senegalese population from this source, we measured the fluoride concentration not only for each component of the prepared tea but also for each cup of prepared tea. For this study, we used the two main kinds of tea existing locally. The analyses have been done at Rochester, NY Eastman Dental Center, Oral Biology Dept Fluoride Laboratory using the Taves Microdiffusion Method and the fluoride Ion Specific Electrode. The results so that the mean total fluoride concentration of each cup, from the first to the third one, is: 4.0 mg F-/L, 7.436 mg F-/L and 1.230 mg F-/L. It means that on an average in one session, a Senegalese tea consumer has a daily fluoride intake of 1.139 mg F-/L when taking in count the total fluoride and drinking only 90 ml of tea. If we consider the ionic fluoride the amount of daily ingested fluoride for someone who takes only 3 tea-pots of 30 ml each, is 0.830 mg. To conclude, we state that this traditional practice may have a caries preventive effect. Further studies will be grateful for that practice when setting up a caries preventive program in our country. We will also be careful in extending that practice to children less than 8 years old because it might cause dental fluorosis as in Senegal the optimal dose of fluoride is 0.8 mg F-/L.

Changes in central alpha-adrenoceptors and noradrenaline content after high sodium intake in Sabra salt-sensitive and salt-resistant rats.

Several studies have suggested a correlation between sodium accumulation and the development of hypertension. However, the mechanisms whereby sodium is able to increase blood pressure remain unclear. In the present study, alpha-adrenoceptors and noradrenaline contents have been studied in the cerebral cortex, hypothalamus and medulla oblongata in the Sabra rat strain in order to define their role in the resistance or sensitivity to sodium-induced hypertension. Alpha-Adrenoceptors were defined using the selective ligands 3H-prazosin and 3H-rauwolscine for alpha 1- and alpha 2-adrenoceptors, respectively. Under normal sodium diet, alpha 2-adrenoceptor density was higher in cerebral cortex and lower in hypothalamus and medulla oblongata of SBN (salt-resistant) compared to SBH (salt-sensitive) rats. Five weeks of high sodium intake induced a decrease in alpha 2-adrenoceptor density in cerebral cortex and an increase in hypothalamus only in SBN rats. These changes abolished the differences between SBH and SBN rats observed with a normal sodium diet. No changes in density and affinity of alpha 2-adrenoceptors were observed in medulla oblongata of SBN and SBH rats. Density and affinity of alpha 1-adrenoceptors were similar in SBN and SBH rats in all the tissues studied and they were unaffected by the high sodium diet. Noradrenaline contents in cerebral cortex, hypothalamus and medulla oblongata were also similar in the two rat substrains under normal sodium diet, but high sodium intake induced a decrease cerebrocortical noradrenaline content only in SBN rats.(ABSTRACT TRUNCATED AT 250 WORDS)