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Full-Text Articles in Physiology

Control Of Blood Volume Following Hypovolemic Challenge In Vertebrates: Transcapillary Versus Lymphatic Mechanisms., Stanley S. Hillman, Robert C. Drewes, Michael S. Hedrick Dec 2020

Control Of Blood Volume Following Hypovolemic Challenge In Vertebrates: Transcapillary Versus Lymphatic Mechanisms., Stanley S. Hillman, Robert C. Drewes, Michael S. Hedrick

Biology Faculty Publications and Presentations

Anurans have an exceptional capacity for maintaining vascular volume compared with other groups of vertebrates. They can mobilize interstitial fluids via lymphatic return at rates that are ten-fold higher than mammals. This extraordinary capacity is the result of coordination of specialized skeletal muscles and pulmonary ventilation that vary volume and pressure of subcutaneous lymph sacs, thus moving lymph to dorsally located lymph hearts that return lymph to the vascular space. Variation in the capacity to mobilize lymph within anurans varies with the degree of terrestriality, development of skeletal muscles, lung volume and lung compliance, and lymph heart pressure development. This …


Hydrophobic Surfactant Proteins Strongly Induce Negative Curvature, Mariya Chavarha, Ryan W. Loney, Shankar B. Rananavare, Stephen B. Hall Jul 2015

Hydrophobic Surfactant Proteins Strongly Induce Negative Curvature, Mariya Chavarha, Ryan W. Loney, Shankar B. Rananavare, Stephen B. Hall

Chemistry Faculty Publications and Presentations

The hydrophobic surfactant proteins SP-B and SP-C greatly accelerate the adsorption of vesicles containing the surfactant lipids to form a film that lowers the surface tension of the air/water interface in the lungs. Pulmonary surfactant enters the interface by a process analogous to the fusion of two vesicles. As with fusion, several factors affect adsorption according to how they alter the curvature of lipid leaflets, suggesting that adsorption proceeds via a rate-limiting structure with negative curvature, in which the hydrophilic face of the phospholipid leaflets is concave. In the studies reported here, we tested whether the surfactant proteins might promote …


Cell Cycle Arrest Associated With Anoxia-Induced Quiescence, Anoxic Preconditioning, And Embryonic Diapause In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Camie Lynn Meller, Robert Meller, Roger P. Simon, Kristin M. Culpepper, Jason E. Podrabsky Jan 2012

Cell Cycle Arrest Associated With Anoxia-Induced Quiescence, Anoxic Preconditioning, And Embryonic Diapause In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Camie Lynn Meller, Robert Meller, Roger P. Simon, Kristin M. Culpepper, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Embryos of the annual killifish Austrofundulus limnaeus can enter into dormancy associated with diapause and anoxia-induced quiescence. Dormant embryos are composed primarily of cells arrested in the G1/G0 phase of the cell cycle based on flow cytometry analysis of DNA content. In fact, most cells in developing embryos contain only a diploid complement of DNA, with very few cells found in the S, G2, or M phases of the cell cycle. Diapause II embryos appear to be in a G0-like state with low levels of cyclin D1 and p53. However, the active form of pAKT is high during diapause II. …


Mitochondrial Physiology Of Diapausing And Developing Embryos Of The Annual Killifish Austrofundulus Limnaeus: Implications For Extreme Anoxia Tolerance, Jeffrey M. Duerr, Jason E. Podrabsky Jan 2010

Mitochondrial Physiology Of Diapausing And Developing Embryos Of The Annual Killifish Austrofundulus Limnaeus: Implications For Extreme Anoxia Tolerance, Jeffrey M. Duerr, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Diapausing embryos of the annual killifish Austrofundulus limnaeus have the highest reported anoxia tolerance of any vertebrate and previous studies indicate modified mitochondrial physiology likely supports anoxic metabolism. Functional mitochondria isolated from diapausing and developing embryos of the annual killifish exhibited VO2, respiratory control ratios (RCR), and P:O ratios consistent with those obtained from other ectothermic vertebrate species. Reduced oxygen consumption associated with dormancy in whole animal respiration rates are correlated with maximal respiration rates of mitochondria isolated from diapausing versus developing embryos. P:O ratios for developing embryos were similar to those obtained from adult liver, but were diminished in …