Effects of specimen preservation and transportation on blood paraquat concentration in rats / 中华劳动卫生职业病杂志

Objective: To investigate the effects of duration, temperature and shake on paraquat (PQ) concentration in the blood of PQ-exposed rats during the specinen preservation and transportation. Methods: In March 2021, 60 SD male rats of Specific Pathogen Free class were randomly divided into low-dose group (10 mg/kg PQ) and high-dose group (80 mg/kg PQ). Each group was divided into 5 subgroups (normal temperature group, cold storage group, 37 ℃ storage group, shaking on normal temperature group and shaking on 37 ℃ group), six rats in each subgroup. The rats were given intraperitoneal injection of PQ, 1 h after exposure, the blood samples were obtained by cardiac extraction. After different interventions, the concentrations of PQ were detected and compared before and after the intervention in each subgroup. Results: In the shaking on 37 ℃ group, the results of PQ concentrations in PQ-exposed rats were significantly lower than those before the intervention (P<0.05). In the other subgroups, the results were not significantly different compared with before intervention (P>0.05) . Conclusion: The concentration of PQ in the blood of rats exposed to PQ was decreased by shaking for 4 hours at 37 ℃.

Effect of Paroxysmal Atrial Fibrillation on Parameters Monitored by Transpulmonary Thermodilution Method / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of atrial fibrillation on the accuracy of parameters monitored by transpulmonary thermodilution method.</p><p><b>METHODS</b>Totally 12 patients from emergency intensive care unit with paroxysmal atrial fibrillation were enrolled. The hemodynamic parameters such as heart rate, mean arterial pressure, cardiac index, systemic vascular resistance index, intrathoracic blood volume index, and extravascular lung water index were monitored by transpulmonary thermodilution method before paroxysmal atrial fibrillation and during atrial fibrillation, the number of B-lines was detected by lung ultrasonography before and during paroxysmal atrial fibrillation. The changes of all the parameters were analyzed.</p><p><b>RESULTS</b>When the paroxysmal atrial fibrillation happened, the heart rate increased significantly [(123.3±20.0) beat/min vs. (98.9±12.3) beat/min, P=0.006]; the mean arterial pressure [(86.9±10.2) mmHg vs. (93.0±12.5) mmHg, P=0.058], cardiac index [(2.82±0.62) L/(min·m(2)) vs. (3.31±1.02) L/(min·m(2)), P=0.058] and systemic vascular resistance index [(2254±947) dyn·s·cm(-5)·m(2) vs. (2302±828) dyn·s·cm(-5)·m(2), P=0.351] had no obvious change; however, the intrathoracic blood volume index significantly increased [(1333±90) ml/m(2) vs. (937±111) ml/m(2), P<0.001]; extravascular lung water index also increased significantly [(16.1±1.1) ml/kg vs. (6.5±1.9) ml/kg, P<0.001]. No significant difference was found in the number of B-lines detected by lung ultrasonography before and during atrial fibrillation (10.0±4.2 vs. 9.4±4.4, P=0.180).</p><p><b>CONCLUSION</b>Both intrathoracic blood volume and extravascular lung water monitored by transpulmonary thermodilution method were overvalued during paroxysmal atrial fibrillation, which may mislead the clinical judgment and decision-making.</p>

Study the effects of Salvia miltiorrhiza monomer IH764-3 on the expression of matrix metalloproteinase in lungs of rats exposed to Paraquat (PQ) / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the expression of the matrix metalloproteinase 2 (MMP-2) and membrane-type 1 metalloproteinase (MT1-MMP) in lung of rats exposed to paraquat (PQ) and the effects of Salvia miltiorrhiza monomer IH764-3 on above expression.</p><p><b>METHODS</b>Ninety adult healthy Sprague-Dawley (SD) rats were randomly divided into the control group (group A, 6 rats), the exposure group (group B, 42 rats) and the group treated by Salvia miltiorrhiza monomer IH764-3 (group C, 42 rats). The group B and C were treated intragastrically with 1ml of PQ (50 mg/kg), and the group A was treated intragastrically with normal saline. The group C was treated intraperitoneally with 1 ml Salvia miltiorrhiza monomer IH764-3 at the dose of 40 mg/kg a day. The group A and B were treated intraperitoneally with 1 ml normal saline day. The expression of MMP-2 and MT1-MMP was detected on the 1st, 3rd, 7th, 14th, 21st, 28th and 35th days after exposure for all groups.</p><p><b>RESULTS</b>As compared with the expression level (0.305 ± 0.045) of MMP-2 mRNA in group A, the expression levels of MMP-2 mRNA in Group B significantly increased, which were 0.654 ± 0.077, 0.623 ± 0.051, 0.637 ± 0.024, 0.533 ± 0.043 and 0.552 ± 0.050 on the 1st, 3rd, 7th, 14th, 21st days after exposure, respectively (P < 0.01). As compared with group A, the the expression levels of MMP-2 mRNA on the 1st, 3rd, 7th days in Group C slightly increased, but the expression levels of MMP-2 mRNA on the 1st, 3rd, 7th, 14th, 21st days in Group C were 0.523 ± 0.074, 0.567 ± 0.097, 0.514 ± 0.058, 0.359 ± 0.018 and 0.374 ± 0.020, respectively, which were significantly lower than those in group B (P < 0.01). As compared with the expression level (0.391 ± 0.058) of MT1-MMP mRNA in group A, the expression levels of MT1-MMP mRNA in Group B significantly increased, which were 0.796 ± 0.021, 0.762 ± 0.043, 0.590 ± 0.010, 0.803 ± 0.076 and 0.680 ± 0.034 on the 1st, 3rd, 7th, 14th and 21st days after exposure, respectively (P < 0.01). As compared with group A, the expression levels of MT1-MMP mRNA in Group C significantly increased, which were 0.594 ± 0.010, 0.653 ± 0.044 and 0.564 ± 0.009 on the 1st, 3rd and 21st days after exposure, respectively (P < 0.01). The expression levels of MT1-MMP mRNA in Group C were significantly lower than those in group B (P < 0.05 or P < 0.01).</p><p><b>CONCLUSION</b>The expression changes of MMP-2 and MT1-MMP genes of lungs in rats intragastrically exposed to PQ could result in the unbalance the synthesis and degradation of ECM, which may be a cause of lung fibrosis. The Salvia miltiorrhiza monomer IH764-3 could affect the expression of MMP-2 and MT1-MMP genes to a certain extent, resulting in the reduction of lung fibrosis.</p>

Pathologic changes and expression of Heme oxygenase-1 in paraquat-induced renal injury / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the mechanism of paraquat-induced renal injury in rats.</p><p><b>METHODS</b>Adult healthy Sprague-Dawley (SD) rats (female and male in half) were randomly divided into two groups, the control group and the paraquat poisoned group. The rats in the paraquat poisoned group were treated with PQ (25 mg/kg) intraperitoneally while the rats in the control group were treated with the same dose of normal saline. Its histopathological change was observed and the expression of HO-1 and the mRNA expression of HO-1 were detected by RT-PCR at 3rd h, 6th h, 12th h, on 1st d, 2nd d, 3rd d and 5th d.</p><p><b>RESULTS</b>(1) In the control group, the tissue structure was clear without edema, vacuolar degeneration, cloudy swelling and necrosis. In the paraquat poisoned group, there were obvious lesions in the renal tubule of cortical part, including cellular swelling, the narrow cannula, the mesenchymal congestion and edema. These pathologic changes gradually became more severe, reached the peak on the 1st day, and did not relieve until the end of this study; there was the karyopyknosis and the cyto-architecture disappeared in some severe cases; Some glomerulus and medulla were also involved. (2) In the control group, there was no or weak expression of HO-1 and HO-1 mRNA. At the 3rd hour, the expressions of HO-1 in the paraquat poisoned group were observed in the membrane and cytoplasm of renal tubular epithelial cell of cortical part. Immunohistochemistry score (IHS) in the paraquat poisoned group was higher than that in the control group (P<0.05), except the HIS of the 5th day. At the 3rd hour, the expression of HO-1 mRNA increased, reached the peak on the 1st day, and then decreased. The expression of HO-1 mRNA was (0.53 +/- 0.21), (0.55 +/- 0.31), (0.56 +/- 0.22), (0.64 +/- 0.14) and (0.43 +/- 0.25) at the time point other than on the 3rd and 5th day. It showed statistical difference between the paraquat poisoned group and the control group from the 3rd hour to the 2nd day (P<0.05).</p><p><b>CONCLUSION</b>The mechanism of paraquat induced-renal injury is multiple. The higher expression of HO-1 and HO-1 mRNA were involved in the procedures of paraquat-induced renal injury.</p>