We have investigated the maximum tolerance and the ventilatory responses of a bat, P. poliocephalus (PP), to normobaric hypoxic stress. PP can tolerate inspired PO2s (PiO2) down to 30 torr. This bat is one of the most hypoxia-tolerant non-hibernating species of mammals known, and has a tolerance which lies within the range of PiO2s reported for different birds. Unlike most mammals in its size range, PP maintains its normoxic oxygen consumption rate even in deep hypoxia. The maximum hypoxic ventilatory response (HVR), the air convection requirement (Vi/MO2), and the lung oxygen extraction (EL) ability of PP in deep hypoxia are all greater than those of other mammals. These and other data indicate that PP has a superior mammalian tolerance for hypocapnia. The magnitudes of both the V1/MO2 and the EL value of PP fall between those reported for Pekin ducks at corresponding PiO2s, and are inferior to the maximum capabilities of bar-headed geese. Thus, the tolerance and ventilatory adjustments of PP to deep hypoxia are intermediate between those of typical non-flying mammals and the most tolerant avian species, and suggest that at least some of this bat's respiratory adaptations for flight may serve as preadaptations for withstanding acute hypoxic stress.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/0300-9629(95)00091-k | DOI Listing |
Endocr Regul
January 2025
1Department of Molecular Biology, Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine.
For the effective growth of malignant tumors, including glioblastoma, the necessary factors involve endoplasmic reticulum (ER) stress, hypoxia, and the availability of nutrients, particularly glucose. The ER degradation enhancing alpha-mannosidase like protein 1 (EDEM1) is involved in ER-associated degradation (ERAD) targeting misfolded glycoproteins for degradation in an N-glycan-independent manner. EDEM1 was also identified as a new modulator of insulin synthesis and secretion.
View Article and Find Full Text PDFCells
March 2025
Departement of Rheumatology, Erasme-HUB Hospital, Université Libre de Bruxelles, 1070 Brussels, Belgium.
Tubulointerstitial hypoxia is a key factor for lupus nephritis progression to end-stage renal disease. Numerous aquaporins (AQPs) are expressed by renal tubules and are essential for their proper functioning. The aim of this study is to characterize the tubular expression of AQP1, AQP2 and AQP3, which could provide a better understanding of tubulointerstitial stress during lupus nephritis.
View Article and Find Full Text PDFSovrem Tekhnologii Med
March 2025
PhD, Senior Researcher, Laser Biospectroscopy Laboratory, Light-Induced Surface Phenomena Department, Natural Sciences Center; Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov St., Moscow, 119991, Russia; Associate Professor, Department 87 "Laser Micro-, Nano-, and Biotechnologies, Engineering Physics Institute for Biomedicine"; National Research Nuclear University MEPhI, 31 Kashirskoye Highway, Moscow, 115409, Russia.
Unlabelled: The application of photosensitizers for inhibition of oxidative phosphorylation in order to temporally decrease oxygen uptake by tumor cells in the course of photodynamic therapy (PDT) evokes growing interest. is to overcome tumor hypoxia for further photodynamic therapy with simultaneous use of type I photosensitizer methylene blue (MB) and type II photosensitizer chlorin e6.
Material And Methods: A photodynamic activity of MB and its combined use with chlorin e6 has been studied on the HeLa cell culture, their effect on cell metabolism in their co-accumulation and subsequent irradiation has also been assessed.
Diabetes Obes Metab
March 2025
Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München, University of Leipzig and University Hospital Leipzig, Leipzig, Germany.
Obesity is a highly prevalent chronic multisystem disease associated with shortened life expectancy due to a number of adverse health outcomes. Epidemiological data link body weight and parameters of central fat distribution to an increasing risk for type 2 diabetes, hypertension, fatty liver diseases, cardiovascular diseases including myocardial infarction, heart failure, atrial fibrillation, stroke, obstructive sleep apnoea, osteoarthritis, mental disorders and some types of cancer. However, the individual risk to develop cardiometabolic and other obesity-related diseases cannot entirely be explained by increased fat mass.
View Article and Find Full Text PDFNat Commun
March 2025
Department of Biomedical and Pharmaceutical Sciences, Chapman University, Irvine, CA, USA.
Progesterone receptors are classified into nuclear and membrane-bound receptor families. Previous unbiased proteomic studies indicate a potential association between cardiac diseases and the progesterone receptor membrane-bound component-2 (PGRMC2); however, the role of PGRMC2 in the heart remains unknown. In this study, we use a heart-specific knockout (KO) mouse model (MyH6•Pgrmc2) in which the Pgrmc2 gene was selectively deleted in cardiomyocytes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!