Fluoride Metabolism in Pregnant Rats.

Abstract

sponse elicited by the strong erythropoietic stimulus of CoC12 is affected by gonadal hormones. Since the values obtained for the castrated males and females fall between those obtained for the intact males and females, the data support the conclusion of previous investigators that testosterone s timulates and estrogen inhibits erythropoiesis.However, when the probabilities of the differences found between intact and castrated males and between intact and castrated females were calculated. p was greater than -05 but less than 0.1 for the former and less than .01 for the latter, suggesting a greater inhibitory effect of estrogen than a stimulatory effect of testosterone.It is of further interest that an estimate of the survival time of the erythrocyte formed in response to CoCl,! stimulation may be made from the data presented. Jt is our interpretation that maximal hematocrit level is reached when rate of erythrocyte destruction equals rate of formation: further, that this level is attained when the cells formed in response to the initial CoC12 injections begin to be removed. Accordingly, from the curves in Fig. 1 and 2 it is estimated that survival time of the erythrocytes formed in response to CoCls is 42-49 days for the female rat and 49-56 days for the male. Burwell, et al.(3) employing radioiron-tagged erythrocytes established survival time of normal red cells of the rat to be 45-50 days. Therefore, estimates of survival time af erythrocytes formed in response to CaCla stimulation, obtained from the hematwrit curves, compare quite favorably with survival times of n o m l cells established by more elaborate procedures.Summary. Following injection of CoClz for 63 days, intact male and female rats attained significantly different maximal hematocrit values of 66.7% at the end of the seventh week for the former and 59.5% at the end of the sixth week for the latter. Intermediate levels of 64.0% and 63.7% were reached by castrated males and females respectively under the same stimulus, both at the end of the seventh week. Survival time of erythrocytes formed in response to CoC12 stimulation appears to be normal.

Prenatal Fluoride Exposure: Measurement of Plasma Levels and Enamel Uptake in the Guinea Pig

“…1960); and humans (Armstrong et al, 1970;Brzezinski et al, 1960;Ericsson and Malmnas, 1962;Feltman, 1956;Feltman and Kosel, 1955;Gedalia, 1970;Gedalia et al, 1964aGedalia et al, , 1964bGedalia et al, , 1965Held, 1952;Martin, 1948;Shen and Taves, 1974;Yudkin et al, 1954). There is a difference of opinion as to whether the placenta serves as a partial barrier to fluoride diffusion (Armstrong et al, 1970;Bawden et al, 1964Bawden et al, , 1965Bell et al, 1961;Brzezinski et al, 1961;Buttner and Muhler, 1958;Ericsson and Hammarstrom, 1964;Ericsson and Malmnas, 1962;Ericsson and Ullberg, 1958;Evans and Phillips, 1939;Held, 1952;Hudson et al, 1967;Katz and Stookey, 1973;Knouft et al, 1936;Lehman and Muhler, 1954;Reid and Cheng, 1937;Roholm, 1937;Shen and Taves, 1974;Suttie et al, 1957;Truhaut, 1948;Yudkin et al, 1954). These inconsistent views may relate to species differences.…”

Influence of Dietary Fluoride Restriction on Regulation of Plasma and Soft Tissue Fluoride Contents

“…Also, no difference between the fluoride contents of the blood of pregnant and nonpregnant rats was found (2), and the constancy of total fluoride content of plasma of humans using communal waters in the range of 0.15-2.5 ppm has been reported (3); however, persons using communal water containing 5.4 ppm had a distinct elevation of total fluoride contents. Also, no difference between the fluoride contents of the blood of pregnant and nonpregnant rats was found (2), and the constancy of total fluoride content of plasma of humans using communal waters in the range of 0.15-2.5 ppm has been reported (3); however, persons using communal water containing 5.4 ppm had a distinct elevation of total fluoride contents.…”

Fluoride Administration in Single Daily Dose

“…Despite large variations in fluoride concentration of water source, plasma fluoride levels remain remarkably constant in rats16,17 and in humans.18 19. Assembled inTable 1are findings from four investiga-tions 12-15 on plasma fluoride concentrations following single dose fluoride administration.…”