An observation of biochemical indexes in the fluorosis accumulation human serum in Qinghai plateau

Objective To observe the content changes of melatonin (MT), serotonin (5-HT), xanthine oxidase (XOD), glutathione over peroxidase (GSH-Px) and calcitionin (CT) in the fluorosis accumulation human serum. Methods Patients with a habit of long-term drinking brick tea and clinically diagnosed skeletal fluorosis were selected in, aged 16~ 65 years, and grouped according to 10-year-old of 16-, 26-, 36-, 46-, 56-years old, each group had 50 people, half males and half females, urine samples were collected for determination of urinary fluoride content; and portable X-ray DR was used to take X-ray photographs; at the same time, their venous blood was collected to detect the content of serum MT, 5-HT, XOD, GSH-Px and CT. Fluoride content of urine was determined by "Fluoride Ion Selective Electrode in Urine" (WS/T 30-1996); X-ray diagnosis of skeletal fluorosis was based on "Diagnostic Criteria for Endemic Skeletal Fluorosis" (WS 192-2008); MT, 5-HT, XOD, GSH-Px and CT were determined with enzyme-linked immunosorbent assay (ELISA). Results Totally 250 patients were checked skeletal fluorosis by X-ray, the prevalence rate of skeletal fluorosis was 73.6% (184/250), of which 88 cases were degree Ⅰ skeletal fluorosis, accounting for 35.2%; 72 cases were degree Ⅱ skeletal fluorosis, accounting for 28.8%; and 24 cases were degree Ⅲ skeletal fluorosis, accounting for 9.6%. Totally 250 urine samples were detected fluoride content, the mean was 2.13 (0.20-12.04) mg/L; of which the urine fluoride content of control group was 1.71 (0.26-4.78) mg/L; that of degree Ⅰ was 1.83 (0.20-10.00) mg/L, that of degree Ⅱ was 2.29 (0.29-8.31) mg/L; that of degree Ⅲ was 3.46 (0.51-12.04) mg/L, as the illness aggravated, there was a tendency of increased urinary fluoride (H= 22.412, P < 0.05). The mean of MT, 5-HT, XOD, GSH-Px and CT in 250 serum samples was (21.80 ± 12.48) ng/L, (362.62 ± 86.70) ng/L, (2 619.83 ± 903.90) ng/L, (51.46 ± 14.13) pmol/L and (762.91 ± 238.18) ng/L. There was a decreasing trends of MT and GSH-Px secretion (F= 197.413, 8.949, all P < 0.05) with aggravation of the disease. MT in the age groups of 16-, 26-, 36-, 46-, 56-was (36.96 ± 3.45), (29.02 ± 3.59), (24.20 ± 1.92), (10.23 ± 5.56) and (5.89 ± 4.12) ng/L, respectively. MT and GSH-Px secretion declined with age (F= 580.021, 2.456, P < 0.05). Conclusion The serum levels of MT and GSH-Px have increased with the severity of the disease and older of age, which needs to be further studied. Key words: Fluorine; Melatonin; Serotonin; Xanthine fluorinated oxidase; Glutathione over peroxidase; Calcitionin