caa a22 4500 605514283 CHVBK 20210128100704.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00360-015-0896-6 doi (NATIONALLICENCE)springer-10.1007/s00360-015-0896-6 Acute and chronic temperature effects on cardiovascular regulation in the red-eared slider ( Trachemys scripta ) [Elektronische Daten] [Dane Crossley II, Oliver Wearing, Bjorn Platzack, Lynn Hartzler, James Hicks] Acute and chronic changes in ambient temperature alter several aspects of reptilian physiology. We investigated the effects of each type of temperature change on reptilian cardiovascular regulation in red-eared slider turtles (Trachemys scripta), a species known to experience marked seasonal changes in ambient temperature. Turtles were instrumented with occlusive catheters in the femoral artery and vein. Following an acclimation period of 10days at 13°C (131), cardiovascular responses to adrenaline, and the cardiac limb of the baroreflex were quantified. Ambient temperature was then reduced 1°Cday−1 until 3°C was reached (31). Turtles were maintained at this temperature for 1-week before cardiovascular responses were reassessed. Turtles were then gradually (1°Cday−1) returned to an ambient temperature of 13°C, (132). After a 1-week re-acclimation period, cardiovascular responses were again determined. Finally, 1-week post-pharmacological manipulation of turtles in the 132 treatment, ambient temperature was reduced to 3°C over 24h (32), and cardiovascular responses were again assessed. Temperature reduction from 131 to 31 decreased mean arterial blood pressure (P m) and heart rate (f H) by ~38 and ~63%, respectively. Acute temperature reduction, from 132 to 32, decreased f H similarly, ~66%; however, while P m decreased ~28%, this was not significantly different than P m at 132. The adrenaline injections increased f H ranging from 90 to 170% at 13°C which was a greater change than that observed at 3°C ranging from a 40 to 70% increase. The increase in P m at the lowest dose of adrenaline did not differ across the temperature treatment groups. The operational point (set-point) P m of the baroreflex was decreased similarly by both methods of temperature reduction (31 or 32). Further, a hypertensive cardiac baroreflex was absent in the majority of the animals studied independent of temperature. Baroreflex gain and normalized gain based on individual estimates of the relationship were decreased by temperature reduction similarly. Collectively, the data suggest that red-eared slider turtles modulate (down-regulate) some cardiovascular control mechanisms during reduced ambient temperature. Springer-Verlag Berlin Heidelberg, 2015 Baroreflex nationallicence Reptilian nationallicence Cardiovascular nationallicence Regulation nationallicence Q10 nationallicence Crossley II Dane Department of Biological Sciences, University of North Texas, 76203, Denton, TX, USA aut Wearing Oliver Faculty of Life Sciences, University of Manchester, M13 9NT, Manchester, UK aut Platzack Bjorn Swedish Toxicology Sciences Research Center (Swetox), SE-151 36, Södertälje, Sweden aut Hartzler Lynn Department of Biological Sciences, Wright State University, 45435, Dayton, OH, USA aut Hicks James Department of Ecology and Evolutionary Biology, University of California, 92697, Irvine, CA, USA aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/4(2015-05-01), 401-411 0174-1578 185:4<401 2015 185 360 https://doi.org/10.1007/s00360-015-0896-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-015-0896-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Crossley II Dane Department of Biological Sciences, University of North Texas, 76203, Denton, TX, USA aut NATIONALLICENCE 700 1- Wearing Oliver Faculty of Life Sciences, University of Manchester, M13 9NT, Manchester, UK aut NATIONALLICENCE 700 1- Platzack Bjorn Swedish Toxicology Sciences Research Center (Swetox), SE-151 36, Södertälje, Sweden aut NATIONALLICENCE 700 1- Hartzler Lynn Department of Biological Sciences, Wright State University, 45435, Dayton, OH, USA aut NATIONALLICENCE 700 1- Hicks James Department of Ecology and Evolutionary Biology, University of California, 92697, Irvine, CA, USA aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/4(2015-05-01), 401-411 0174-1578 185:4<401 2015 185 360