... oxygen: chronic anoxia exposure reduces mitochondrial F 1 F O -ATPase activity in turtle ( Trachemys scripta ) heart . J. Exp. Biol 216 , 3283 - 3293 . 10.1242/jeb.087155 Gardner , P. R. ( 2002 ). Aconitase: sensitive target and measure of superoxide . Methods Enzymol. 349 , 9...

... Trachemys scripta elegans , a species undergoing strong metabolic suppression when cold and anoxic. In warm normoxic turtles, free H 2 S was higher in red blood cells (RBCs) and kidney (∼9–10 µmol l −1 ) than in brain, liver and lung (∼1–2 µmol l −1 ). These values overall aligned with the tissue H 2 S...

... the phenotypic consequences of elevated corticosterone during development, and characterizing the levels of maternally transferred corticosterone in unmanipulated eggs using Trachemys scripta . By dosing eggs with tritiated corticosterone and tracking the steroid throughout development, we found that most...

... and birds, do not maintain high arterial P O 2  during routine activities. Oxygen levels are highly variable and often increase rather than decline during underwater breath holds. Turtle Arterial P O 2 Trachemys scripta Cardiac shunt Blood oxygen depletion Diving Across air...

... in the humoral immune system of the red-eared slider turtle, Trachemys scripta , which supports the idea that non-specific, natural antibody responses are an important line of defense in reptiles. Overall, this demonstrates that a taxon’s immune strategy can influence how the immune system is affected by age...

...Jonathan A. W. Stecyk; Anthony P. Farrell SUMMARY Heart rate ( f H ) of the anoxia-tolerant freshwater turtle ( Trachemys scripta ) during prolonged anoxia exposure is 2.5-to 5-times lower than the normoxic rate, but whether alterations in blood composition that accompany prolonged anoxia...

... synthesis during anoxia with no post-anoxia protein synthesis debt in the red-eared slider turtle Trachemys scripta elegans. J. Exp. Biol. 204 , 4353 -4360. Haddad, J. J. ( 2002 ). Oxygen-sensing mechanisms and the regulation of redox-responsive transcription factors in development...

... ( Oncorhynchus mykiss ) ventricular muscle changes with cycle frequency. J. Exp. Biol. 205 , 697 -706. Hicks, J. M. and Farrell, A. P. ( 2000 ). The cardiovascular responses of the red-eared slider ( Trachemys scripta )acclimated to either 22 or 5°C. I. Effects of anoxic exposure on in vivo cardiac...

...Gina Galli; E. W. Taylor; Tobias Wang SUMMARY Seven freshwater turtles Trachemys scripta were instrumented with flow probes and cannulated for blood pressure measurements. The turtles were warmed from 24 to 34°C, and cooled down to 24°C, with and without atropine. Animals exhibited a hysteresis...

... resistance ( R sys ). Here,we investigate the role of the α-adrenergic system in modulating R sys during anoxia at 5°C and 21°C in the turtle Trachemys scripta , and also describe how anoxia affects relative systemic blood flow distribution(% Q̇ sys ) and absolute tissue blood flows. Turtles were...

...Johannes Overgaard; Jonathan A. W. Stecyk; Anthony P. Farrell; Tobias Wang SUMMARY Freshwater turtles, Trachemys scripta , like all non-crocodilian reptiles, are able to shunt blood between the pulmonary and systemic circulations owing to their undivided ventricle. The prevailing hypothesis...

... ), systemic cardiac output (Q̇ sys ), heart rate ( f H ), systemic stroke volume ( V s,sys ), systemic resistance ( R sys ) and mean arterial pressure ( P sys ) in red-eared sliders ( Trachemys scripta ). The effects of cold acclimation and anoxic exposure were studied. Turtles were acclimated to either 22 °C...

...J. M. T. Hicks; A. P. Farrell ABSTRACT Cardiovascular control in cold-acclimated freshwater turtles during chronic anoxic exposure is not well understood. We tested the hypothesis that the observed bradycardia in Trachemys scripta results from increased cholinergic inhibitory tone and reduced...

... elicits an increase in pulmonary vasculature resistance in anesthetised turtles ( Trachemys scripta ) . J. Exp. Biol . 201 , 3367 – 3375 . 10.1242/jeb.201.24.3367 Douse , M. A. and Mitchell , G. S. ( 1990 ). Episodic respiratory related discharge in turtle cranial motoneurons...

...B. Bagatto; R. P. Henry ABSTRACT The dynamics of bimodal respiration, diving behaviour and blood acid–base status in the softshell turtle Trachemys scripta and the pond slider Apalone ferox were investigated at rest and under conditions of stress induced by exercise and forced submergence. During...

... reptiles respond in a similar fashion. The present study describes the effects of altering lung oxygen levels (at a constant of 0.03) on systemic and pulmonary blood flows and pressures in anaesthetised (Nembumal, 50 mg kg −1 ) and artificially ventilated turtles Trachemys scripta . During severe hypoxia...

... vascular blood flows, we examined the effect of manipulating lung volume (and therefore PSR stimulation) on blood flows and heart rate in the freshwater turtle Trachemys scripta . Turtles were instrumented with blood flow probes on the left aortic arch and the left pulmonary artery for measurements...

... the hypothesis that extracellular adenosine plays a role in the reduction of K + flux (channel arrest) that occurs in the anoxic turtle brain. Changes in extracellular K + concentration ([K + ] o ) in the in situ brain of the turtle Trachemys scripta were monitored following inhibition of Na + /K + -ATPase...

... vertebrates. Using epi-illumination microscopy in vivo to observe CBF velocity on the brain surface (cerebral cortex), we show that turtles ( Trachemys scripta ) exposed to hypercapnia (inspired ) displayed a 62 % increase in CBF velocity, while systemic blood pressure remains constant. Exposing turtles...

...Atsushi Ishimatsu; James W. Hicks; Norbert Heisler ABSTRACT Blood distribution within the ventricle was analysed in acutely prepared turtles Trachemys scripta by measuring the oxygen concentration and flow rates of blood in the central vessels. Pulmonary ( Q̇ p ) and systemic ( Q̇ s ) blood flow...