Hypoxia has been identified as an important stimulus for gene expression during embryogenesis and in various pathological situations. Its influence under physiological conditions, however, has only been studied occasionally. We therefore investigated the effect of intermittent high altitude hypoxia on the mRNA expression of different cytokines and protooncogenes, but also of other genes described to be regulated by hypoxia, in the left ventricle (LV), the right ventricle (RV), atria and the lung of adult rats after simulation of hypoxia in a barochamber (5000 m, 4 hours to 10 days). Heme oxygenase-1 as well as transforming growth factor-β1 showed an increased expression in all regions of the heart and the lung at different periods of hypoxia. For lactate dehydrogenase-A, we found a significant up-regulation in the RV and the lung, for lactate dehydrogenase-B up-regulation in the RV, but down-regulation in the LV and the atria. Vascular endothelial growth factor was up-regulated in the RV, the LV and the lung, but down-regulated in the atria. Its receptor Flk-1 mRNA was significantly increased in the atria and RV only. Expression of c-fos was found in the LV and RV only after 4 hours of hypoxia. The level of c-jun was significantly increased in the LV but decreased in the atria. Our data clearly demonstrate that intermittent hypoxia is a modulator of gene expression under physiological conditions. It differently regulates the expression of distinct genes not only in individual organs but even within one organ, i.e. in the heart., E. Deindl, F. Kolář, E. Neubauer, S Vogel, W. Schaper, B. Ošťádal., and Obsahuje bibliografii
We investigated neuronal activity of the medulla oblongata
during gastroesophageal reflux-related cough (GERC). A rat
model of GERC was generated by perfusing HCl into lower
esophagus and inducing cough with citric acid. The HCl group rat
was received HCl perfusion without citric acid-induced cough.
The saline control rat was perfused with saline instead and cough
was induced. Citric acid-induced cough rat was only induced by
citric acid. Blank group rats were fed normally. Fos expressions
were observed in medulla oblongata nuclei using
immunohistochemistry. Manganese-enhanced magnetic
resonance imaging (MEMRI) was performed to detect the
Mn2+ signal following intraperitoneal injection of MnCl2. HCl
perfusion and citric acid-induced cough caused Fos expressions in
the nucleus of solitary tract (nTS), dorsal motor nucleus of the
vagus (DMV), paratrigeminal nucleus (Pa5), and intermediate
reticular nucleus (IRt), which was higher than HCl group, saline
control group, citric acid-induced cough group, and blank group.
A high Mn2+ signal was also observed in most of these nuclei in
model rats, compared with blank group animals. The Mn2+ signal
was also higher in the HCl, saline and citric acid-induced cough
group animals, compared with blank group animals. The study
showed medulla oblongata neurons were excited in a HCl
perfusion and citric acid-induced cough rat model, and nTS, DMV,
Pa5 and IRt neurons maybe involved in the cough process and
signal integrate.