Chang Qing, Rong Chengxing, Shiming Zhang - "Effects of fluoride exposure of female mice on the thyroid’s morphology and function as well as ontogeny of fetuses and neonates" Guangdong Anatomy Bulletin 19(2):17-21 (1997) PFPC Library
GROUP C: Control
GROUP F1: Drinking fluoride water, after mating only (200 mg/L NaF- => 91.2 mg/L of F-)
GROUP F2: Drinking fluoride water for 12 weeks, before and after mating (200 mg/L NaF- => 91.2 mg/L of F-)
"When the mother mouse is exposed to fluoride from conception, the blood T4 and follicular cell height in the fetal (F1) mice are significantly higher than the levels in the normal control group at the same period, exhibiting changes resembling 'hyperthyroidism'. In the case of prolonged chronic fluoride exposure before and during pregnancy in the parent mice, the T4 levels in the fetal (F2) mice are higher at certain sampling times, showing a pattern of 'hyperthyroidism'.
The experiment also observed the impact of fluoride on mouse thyroid development, indicating that the effects on embryonic thyroid development and low iodine are basically similar...These findings suggest that fluoride exposure may lead to thyroid dysfunction in fetal (offspring) mice, and the effects are influenced by the timing and duration of fluoride exposure. The alterations in thyroid function and morphology observed in this study may be associated with the interference of fluoride in the synthesis and secretion of thyroid hormones."
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Chang Q, Li Z - "Study of toxic effect of fluoride on reproduction of female mice and development of their offspring" Guangdong Medical Journal 23(4):353-355 (2002) PFPC Library
Abstract:
Objective:
To discuss the effects of high-fluoride intake and iodine-deficiency on thyroid glands of pregnant mice and their offspring.
Methods:
200 mg/ L sodium fluoride solution was supplied ad.lib. for the adult female Kunming mice before pregnancy and during pregnancy with iodine-sufficiency and iodine-deficiency. The morphological changes and functions of thyroid glands and the body weights of the pregnant mice and their offspring were observed and measured.
Results:
Under the condition of iodine-sufficiency, significantly higher levels of blood T4 in pregnant mice exposed to high-dose fluoride and their offspring were observed compared with those of control group. Significantly heavier body weights were found in 18 d-pregnant mice and 7 d-old offspring compared with those of control group (P<0.01 or P<0.001). Under the condition of iodine-deficiency, significantly lower levels of blood T4 were found in the pregnant mice exposed to high-dose fluoride and their offspring compared with those of control group. Significantly lower levels of body weights were observed in 7 d-old offspring compared with those of control group( P<0.05, P<0.01 or P<0.001) . The indexes, qualitative and quantitative, reflecting the morphological changes of thyroid glands of the mice in each group were consistent with the changes of the functional indexes of thyroid glands.
Conclusion:
Over intake of fluoride revealed a certain impairment on the morphology and function of thyroid glands of the pregnant mice and their offspring. The relative deficiency of iodine and other trace elements might enhance the adverse effects induced by over intake of fluoride. The combination of over intake of fluoride and deficiency of iodine could affect the development of offspring which might be associated with the thyroid glands damaged.
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Chen Peizhong, Yun Zhongjie, Sun Guodong, Wang Yutao, Gao Hongxu, Ma Aihua, Lou Zhanyu - "Effects of high fluoride on endocrine hormone levels in the body" Endemic Disease Bulletin 19(2):14-16 (2004) PFPC Library
Abstract:
Purpose:
Investigate the impact of a high fluoride state on relevant endocrine glands and their relationship with hormone levels.
Methods:
Employing an epidemiological case-control research approach, the serum levels of pituitary, thyroid, and gonadal hormones in experimental animals (Kunming mice) and populations from high-fluoride areas were measured to observe the relationship between high fluoride and the mentioned endocrine glands.
Results:
With an increase in fluoride dosage, the serum levels of thyrotropin (TSH), thyroxine (T4), and estradiol (E2) in experimental mice showed a dose-dependent decrease, with the high-dose group (500mg/L NaF) significantly lower than the control group (P<0.05). Testosterone (T) levels in adult males from high-fluoride areas decreased significantly (P<0.05), while luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels increased (P<0.05). In the female population from high-fluoride areas, serum LH, FSH, E2, and progesterone (P) levels were lower than those in the control group, with LH and E2 levels significantly reduced (P<0.05).
Conclusion:
A high fluoride state can disrupt the secretion function of the pituitary, thyroid, and gonadal endocrine glands. The impact of fluoride on the endocrine function of the body can be transmitted to offspring through the reproductive process, leading to damage in the next generation.
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Wu Nanping, Zhao Zhongliang, Gao Wenhua, Wang Dongyan - "The effect of low-dose fluoride intake on the thyroid function of offspring rats" Chinese Journal of Endemic Diseases Control 8(4):244 (1993) PFPC Library
Pregnant rats were exposed to fluoridated water at concentrations of 1, 5, and 25 mg/L, using boiled and cooled tap water. The control group was given tap water boiled and cooled, containing 0.6mg/L of oxygen. The fluoride water was provided freely. After giving birth, mother rats continued to drink water containing fluoride until weaning. After weaning, the offspring continued to drink water with the same fluoride concentrations until 90 days, after which they were euthanized, and blood serum was collected. Each group consisted of 10 rats, with an equal distribution of males and females.
"In the 5mg/L group, the T4 content was significantly lower than the control and 1mg/L groups (P<0.05). In the 1mg/L group, female T4 content was significantly higher than males in the same group (P<0.05), and it was also significantly higher than females in the 5 and 25mg/L groups (P<0.01). Except for the control group, there were gender differences in the T4/T3 ratio in each group. In the 1mg/L group, females were significantly higher than males, while in the 5 and 25mg/L groups, males were significantly higher than females. The T4/T3 ratio in the 5 and 25mg/L groups for females was also significantly lower than the control and 1mg/L groups (P<0.05). The T4/T3 ratio in the 5mg/L group was significantly lower than the control group (P<0.05)."