Study on activities and protein and gene expression of renal H(+)-K(+)-ATPase in rats subchronic exposed to trimethyltin chloride / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the activity, protein and gene expression of renal HK-ATPase (HKA) in rats subchronic exposed to trimethyltin chloride (TMT).</p><p><b>METHODS</b>In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 microg x kg(-1) x d(-1) for 14 weeks. Then serum K+ levels were measured; the activities of HK-ATPase (HKA) in kidneys were detected by the method of determinated phosphorus content; Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively.</p><p><b>RESULTS</b>The serum K+ level in super-high dosage group was (5.6 +/- 0.4) mmol/L, which was significantly lower than that [(6.9 +/- 0.3) mmol/L] in control group (P < 0.01). The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50 +/- 1.45 and 4.55 +/- 0.72 micromolPi x mg prot(-1)h(-1), respectively, which were significantly lower than that (6.55 +/- 0.77 micromol Pi x mg prot(-1) h(-1)) in control group (P < 0.05).</p><p><b>CONCLUSION</b>When rats were exposed subchronic to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.</p>

Establishment and application of oncogene over expressed human epithelial cell transformation model / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish human bronchial epithelial cell lines over expressing oncogene and to investigate its application in detection of carcinogen-induced cell transformation.</p><p><b>METHODS</b>Mediated by retrovirus infection, human telomerase catalytic subunit, hTERT was introduced into immortal human bronchial epithelial cells (16HBE) and followed by introduction of the oncogenic allele H-Ras(V12), or c-Myc or empty vector, creating cell lines 16HBETR, 16HBETM and 16HBETV, respectively. Biological characteristics of these cell lines including morphology, proliferation, and chromosomal aberration were examined to access whether they were transformed. Soft agar experiment and nude mice subcutaneous injection were performed using pre-transformed 16HBE cells induced by known carcinogens, nickel sulfate (NiSO4) and 7, 8, -dihydrodiol-9, 10-epoxide benzo[a] pyrene (BPDE).</p><p><b>RESULTS</b>With detection of telomerase activity and Western blotting, the expression of target proteins was verified. Thus, the transgenic 16HBE cell lines were successfully established. Cells expressing oncogene H-Ras or c-Myc grew 30.3% or 10.4% faster than control cells. However, these cells failed to form colonies in soft agar or form tumor in nude mice. 16HBETR, 16HBETM cells obtained transformed phenotype at 5 wks, 11 wks, respectively after treatment with BPDE, which are 15 wks and 9 wks earlier than control cells 16HBETV (20 wks). Meanwhile, 16HBETR, 16HBETM cells obtained transformed phenotype at 11 wks, 14 wks, respectively after treatment with nickel sulfate, which are 21 wks and 18 wks earlier than control cells (32 wks).</p><p><b>CONCLUSION</b>With the advantage of shorter latency, transgenic human cell transformation models could be used in potent carcinogen screening and applied to chemical-carcinogenesis mechanism study.</p>

The effect on apoptosis in anterior pituitary induced by cadmium chloride and its relations with caspase-9 pathway / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the effects of cadmium chloride in anterior pituitary and the relation between apoptosis and expression of procaspase-9 mRNA.</p><p><b>METHODS</b>In vivo studies:40 SD male rats were randomly distributed into four groups which were administered with CdCl2 at different doses by gavage for 6 weeks;</p><p><b>IN VITRO STUDIES</b>the rats' anterior pituitary cells were primarily cultured for 120 hours, then treated with CdCl2 at the dose of 0, 1.56, 3.12, 6.25, 12.50, 25.00, 50.00, 100.00 micromol/L for 6 hours; The indices included: expression of procaspase-9 mRNA, detection of apoptosis with TUNEL assay.</p><p><b>RESULTS</b>The results showed the excretion of ACTH, LH seemed to be decreased dramatically and the apoptosis inclined to enhance remarkably, and further more, the expression of procaspase-9 mRNA appeared to be increased significantly as compared with those of the control. It was show that a dose-effect relationship between the CdCl2 dosing and indices above with the regression analysis and a linear correlation between the mean gray value of apoptosis cell and the relative gray value of procaspase-9 mRNA positive cell. The results indicated that damnification, for example, apoptosis could be caused by certain dose of CdCl2 in anterior pituitary cells with dose dependent manner. Caspase-9 might play a role in the occurrence of apoptosis.</p><p><b>CONCLUSION</b>It was suggested that cadmium could induce apoptosis of anterior pituitary both in vivo and in vitro in the manner of dose-dependent, and caspase-9 might play a role during above processes.</p>