Efficacy of fenestrated atrial septal defect occulders on pulmonary hypertension dogs / 中华心血管病杂志

Objective: To explore the short-term efficacy of fenestrated atrial septal defect (ASD) occulders in the treatment of pulmonary arterial hypertension (PAH). Methods: Thirty-six healthy dogs were divided into the balloon atrial septostomy (BAS)+fenestrated ASD occulders group (n=12), BAS group (n=12) and non-septostomy group (n=12). PAH was induced by intra-atrial injection of dehydrogenized monocrotaline (1.5 mg/kg) in all dogs. Animals in the BAS+fenestrated ASD occulders group underwent atrial septal puncture and fenestrated ASD occulders implantation. Animals in the BAS group underwent balloon atrial septostomy. The non-septostomy group received no surgical intervention. The hemodynamic indexes and blood N-terminal pro-B-type natriuretic peptide (NT-proBNP) of dogs were measured before modeling, 2 months after modeling, 1, 3, and 6 months after surgery, respectively. Echocardiography was performed to observe the patency of the shunt and atrial septostomy of the dogs in the BAS+fenestrated ASD occulders group and BAS group at 1, 3, and 6 months after surgery. Three dogs were sacrificed in each group at 1, 3, and 6 months after surgery, respectively. Atrial septal tissue and fenestrated ASD occulders were removed to observe the patency and endothelialization of the device. Lung tissues were obtained for hematoxylin-eosin (HE) staining to observe the inflammatory cells infiltration and the thickening and narrowing of the pulmonary arterials. Results: Among 36 dogs, 2 dogs died within 24 hours after modeling, and 34 dogs were assigned to BAS+fenestrated ASD occulders group (n=12), BAS group (n=11), and non-septostomy group (n=11). Compared with BAS group, the average right atrial pressure (mRAP) and NT-proBNP of dogs in the BAS+fenestrated ASD occulders group were significantly reduced at 3 months after surgery (P<0.05), and the cardiac output (CO) was significantly increased at 6 months after surgery, arterial oxygen saturation (SaO2) was also significantly reduced (P<0.05). Compared with non-septostomy group, dogs in the BAS+fenestrated ASD occulders group had significantly lower mRAP and NT-proBNP at 1, 3, and 6 months after surgery (P<0.05), and higher CO and lower SaO2 at 6 months after surgery (P<0.05). Compared with the non-septostomy group, the dogs in the BAS group had significantly lower mRAP and NT-proBNP at 1 month after surgery (P<0.05), and there was no significant difference on mRAP and NT-proBNP at 3 and 6 months after surgery (P>0.05). Echocardiography showed that there was a minimal right-to-left shunt in the atrial septum in the BAS group at 1 month after the surgery, and the ostomy was closed in all the dogs in the BAS group at 3 months after the surgery. There was still a clear right-to-left shunt in the dogs of BAS+fenestrated ASD occulders group. The shunt was well formed and satisfactory endothelialization was observed at 1, 3 and 6 months after surgery. The results of HE staining showed that the pulmonary arterials were significantly thickened, stenosis and collapse occurred in the non-septostomy group. Pulmonary microvascular stenosis and inflammatory cell infiltration in the pulmonary arterials were observed in the non-septostomy group. Pulmonary arterial histological results were comparable between BAS+fenestrated ASD occulders group and non-septostomy group at 6 months after surgery . Conclusions: The fenestrated ASD occulder has the advantage of maintaining the open fistula hole for a longer time compared with simple balloon dilation. The fenestrated ASD occulder can improve cardiac function, and it is safe and feasible to treat PAH in this animal model.

Effect of swimming exercise on the expression of apelin and its receptor in pulmonary tissues of rats with hypoxic pulmonary hypertension / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the effects of swimming exercise on the expression of apelin and its receptor (APJ) system in pulmonary tissues of rats with pulmonary hypertension induced by hypoxia.</p><p><b>METHODS</b>Forty-five male SD rats were randomly divided into control group, hypoxia group (seven-week) and swimming group (four-week swimming group after three-week hypoxia). The animal model of hypoxic pulmonary hypertension was established by exposing the rats to isobaric hypoxic chamber (8 h/d, 6 d/w). The rats of swimming group swam 60 min/day, 7 d/week for 4 weeks after three-week hypoxia. The mean pulmonary arterial pressure (mPAP) and the mean carotid arterial pressure (mCAP) were measured by either right or left cardiac catheterization, and the weight ratio of right ventricule/left ventricle plus septum [RV/(LV + S)] were calculated. The Masson's trichrome stained lung specimens were used by light microscope to examine the vessel wall area/total area (WA/TA), vessel cavity area/total area (CA/TA) and media thickness of pulmonary arterioles (PAMT). Meanwhile, apelin/ APJ expressions were determined by Western blot and immunohistochemistry.</p><p><b>RESULTS</b>(1) mPAP and RV/(LV + S) of hypoxia group were higher than those of control group by 73.6% and 31.2% (P < 0.01), and mPAP and RV/(LV + S) of swimming group were lower than those of hypoxia group by 21.1%and 8.9 % (P < 0.05), respectively. (2) Masson's trichrome staining revealed that WA/TA and PAMT of hypoxia group were higher than those of control group by 70.8% and 102%. However, WA/TA and PAMT of swimming group were lower than those of hypoxia group by 24.8% and 40.1% (all P < 0.01), respectively. CA/TA of hypoxia group was lower than that of control group by 15.1%, and CA/TA of swimming group was lower than that of hypoxia group by 10.3% (all P < 0.01). (3) Compared with control group, hypoxia group showed up-regulated apelin expression and down-regulated APJ expression in pulmonary tissues (all P < 0.01). Compared with hypoxia group, swimming group showed decreased apelin expression and elevated APJ expression in pulmonary tissues (all P < 0.01). (4) Apelin localized mainly in intracytoplasm of inflammatory cell and tunica adventitia of vessel, and APJ were in vascular intima and tunica externa and plasmalemma of inflammatory cell.</p><p><b>CONCLUSION</b>The improving effect of swimming exercise on hypoxic pulmonary hypertension in rats could be mediated by regulating the pulmonary apelin/APJ system.</p>

Effect of tamoxifen on proliferation of cultured breast cancer and cervical carcinoma cell lines / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effects of tamoxifen on proliferation of human breast cancer Bcap-37 cells and cervical carcinoma HeLa cells and to explore it's possible mechanism.</p><p><b>METHODS</b>The techniques of cell culture, growth curves, flow cytometry and laser scanning confocal microscope were used.</p><p><b>RESULTS</b>Tamoxifen (10(-6) mol/L) shifted the growth curve of Bcap-37 cells downward, and shifted the growth curve of HeLa cells upward. Tamoxifen (10(-8) - 10(-6) mol/L) inhibited the proliferation of Bcap-37 cells in a dose-dependent manner, but stimulated the proliferation of HeLa cells in a dose-dependent manner. Bcap-37 cells appeared apoptosis when treated with tamoxifen (10(-6) mol/L), and the same dose stimulated the proliferation of HeLa cells at GI/S phases. The apoptotic rate of Bcap-37 cells was 97.5%. It blocked G1 phase of HeLa cells from 55.5% to 32.8%, and increased the S phase from 29.0% to 49.4%. Tamoxifen (10(-6) mol/L) also increased the releasing of calcium in Bcap-37 and HeLa cells.</p><p><b>CONCLUSION</b>Tamoxifen can significantly influence the proliferation of breast cancer and cervical carcinoma cells possibly by affecting cell cycle and stimulating the releasing of Ca2+ in the cells.</p>

Expression of interleukin-2 receptors on breast cancer cell line MCF-7 cells / 中国应用生理学杂志

<p><b>AIM</b>To investigate the expression of interleukin-2 receptors (IL-2Rs) on MCF-7 cells, estradiol's regulation of IL-2Rs expression and the influence of IL-2 on the proliferation of MCF-7 cells.</p><p><b>METHODS</b>Immunocytochemistry and flow cytometric analysis were used to investigate the expression of interleukin-2 receptors (IL-2Rs) by using of specific IL-2R polyclonal antibody; MTT method and 3H-TdR incorporation method were used to examine the changes of proliferation of MCF-7 cells.</p><p><b>RESULTS</b>IL-2Ralpha, beta, gamma like immunoreactive substances can be found on MCF-7 cells and the IL-2Rgamma immunostaining was more strong than the other two. Estradiol of 10(-6) mol/L can increase the percentage of immunoreactive cells of IL-2Ralpha, beta and the expression of IL-2Rgamma. Exogenous addition of recombinant IL-2 of 100 U/ml to 1 000 U/ml can significantly increase the proliferation of MCF-7 cells.</p><p><b>CONCLUSION</b>MCF-7 cell can express IL-2R and estradiol can regulate their expression, IL-2 can influence the proliferation of MCF-7 cells.</p>