Effect of nourishing and purging fire Chinese herbal mixture on delaying light-induced premature puberty in rats.

OBJECTIVE: To elucidate the mechanism of the nourishing Yin and purging fire Chinese herbal mixture (NYPF) in delaying light-induced premature puberty in rats. METHODS: Twenty-one days old female Sprague-Dawley rats were randomly assigned to normal group (N), long light exposure group (L), NYPF and normal saline group (NS). Rats in the L, NYPF and NS groups were exposed to 16 h: 350 lux light/8 h: dark, while rats in the N group were exposed to 12 h: 50 lux light/12 h: dark. NYPF and normal saline was administered to the rats in the NYPF group or NS group, respectively, from day 21. Five rats in every group were sacrificed at 9 p.m. on day 28 (P28), on the day when rat's vulva opened in the L group (L-VO), on the day when the first estrous interphase occurred in rats of L group (L-E1), and on the day when the second estrous interphase occurred in rats of L group (L-E2), respectively. RESULITS: On day 34, all rats in the L group, 80% of rats in the NS group, 40% of rats in the N group, and 20% of rats in the NYPF group showed complete opening of the vulva. At P28, mRNA level of hypothalamic kisspeptin (Kiss-1) in the L group was significantly higher than that in the N group (P < 0.05). The rats in the L and NS groups had significantly lower hypothalamic arginine-phenylalanine-amide (RFamide)-related peptide 3 (RFRP-3) mRNA levels than those in the N group (P < 0.05), whereas RFRP-3 mRNA level was significantly higher in the NYPF group than that in the L group (P < 0.05). At L-VO, the ovarian index of the L and NS groups was significantly higher than that of the N group (P < 0.05) and estradiol (E2) level of the NYPF group was significantly lower than that of the N and NS groups (P < 0.05); hypothalamic Kiss-1 mRNA level in the L and NS groups was significantly higher than that in the N and NYPF groups (P < 0.05), whereas hypothalamic RFRP-3 mRNA level in the L, NYPF, and NS groups was significantly lower than that in the N group (P < 0.05). At L-E1, E2 level of the L and NS groups was significantly higher than that of the N group (P < 0.01), whereas it was significantly lower in the NYPF group than that of the N, L, and NS groups (P < 0.01), and serum luteinizing hormone level of the L and NS groups was significantly higher than that of the N group (P < 0.05); levels of serum melatonin and ovarian melatonin receptor 1 (MT-1) mRNA in the L, NYPF, and NS groups were significantly lower than those in the N group (P < 0.05). At L-E2, the uterine organ index of the NYPF group was significantly lower than that of the L group (P < 0.05); and ovarian MT-1 mRNA level of the L and NS groups was significantly lower than that in the N group (P < 0.05). CONCLUSIONS: NYPF can delay puberty onset in rats exposed to strong light for a prolonged duration, and regulation of the gene expression of Kiss-1 and RFRP-3 in the hypothalamus has been suggested as one of the mechanisms.

Effects of amino acids on conversion of calcium carbonate to hydroxyapatite.

Conversion of calcium carbonate (calcite; CC) to hydroxyapatite (HAp) was examined when the CC particles of sub µm size were soaked at 37 °C for up to 10 d in 0.15 M K2HPO4 (20 ml), whose pH was set to 3-12. Here, the solution contained amino acids, such as glutamine (Glu), arginine (Arg), and glycine (Gly), and their content varied from 0-1.0 g per ml of solution. From the X-ray diffraction (XRD) intensity of the 104 and 211 diffractions of calcite and apatite, respectively, it was seen that the presence of the amino acids promoted the conversion. This was supported by the thermogravimetry (TG) results. The highest promotion was observed at 0.5 g addition of amino acids to the phosphate solution, while Glu showed the highest promotion among the amino acids and Gly the lowest. A scanning electron microscopy study indicated that petal-like HAp nano-crystallites covered the entire surface of the CC particles when they were soaked in the phosphate solution with 0.1 g or more of amino acid for 10 d. The XRD intensity ratio 104(CC)/211(HAp) indicated greater CC to HAp conversion in the solutions at pH 3 and 6 than in the more alkaline solutions. This was attributed to the dissolution of CC in the acidic solutions, which was confirmed by bubbling in these solutions.

[Changes in chemokine receptor 4, interleukin-6, and collagen X expression in the ATDC5 cell line stimulated by cyclic tensile strain and stromal cell-derived factor-1].

OBJECTIVE: This study further explores the stromal cell-derived factor-1 (SDF-1)/chemokine receptor 4 (CXCR4) signaling axis mechanism in temporomandibular joint osteoarthritis (OA) by detecting the changes in CXCR4, interleukin (IL)-6, and collagen X expression in the ATDC5 cell line stimulated by the cyclic tensile strain and SDF-1. METHODS: Insulin-transferrin-selenium (ITS) was used to induce ATDC5 cells to differentiate into chondrocyte-like cells. After three weeks, the cells were divided into two groups: those with and without cyclic tensile strain. These groups were further divided into the negative control and SDF-1 groups. Strain force of 20% was applied. After 12 h, the total proteins were extracted from cells of the four groups, and Western blot analysis was used to detect the changes in CXCR4, IL-6, and collagen X expression. RESULTS: SDF-1 could enhance CXCR4, IL-6, and collagen X expressions in the chondrocytes, and 20% tensile strain force could further upregulate the three factors. CONCLUSION: Under abnormal tensile force, SDF-1 can upregulate its specific receptor CXCR4, thus increasing its-binding efficiency and resulting in the activation of the SDF-1/CXCR4 axis. This condition enhances the expressions of IL-6 and other inflammatory factors and directly damages to cartilage tissue. Such damage directly promotes chondrocyte hypertrophy, which enhances collagen X expression.