Lack of effect of helium breathing on catecholamine levels in the adrenal vein blood of the rabbit.
Catecholamine levels were measured in the adrenal vein blood of the chloralose anesthetized rabbit during periods of helium-oxygen breathing (50% He-50% O2) and of air breathing. Blood samples were taken from the T-arm of a venous shunt made by cannulating the renal vein proximally to the orifice of the adrenal vein and connecting the distal end of the cannula to one in the femoral vein. Adrenal vein blood flow varied from 0.09-0.30 g/min in five animals, and catecholamine release from 10-92 ng/min. There were large differences between levels from animal to animal but no significant differences in any one animal between levels measured while breathing helium and levels measured while breathing air. The same held true for respiratory rate, blood pressure, heart rate, and percent change in blood pressure during a simulated valsalva maneuver. Although there were changes seen in catecholamine release during some of these experiments, they could not be related to an effect of gases breathed. It is concluded that if there was an effect of helium breathing on catecholamine release in these anesthetized rabbits it was masked by other conditions with stronger action on the sympatho-adrenal system.
D000311:Adrenal Glands / Q000098:blood supply / Q000378:metabolism*; D000388:Air; D000818:Animals; D001794:Blood Pressure; D002395:Catecholamines / Q000097:blood*; D006339:Heart Rate; D006371:Helium / Q000494:pharmacology*; D011817:Rabbits; D012119:Respiration; D014636:Valsalva Maneuver; D014680:Veins
D002395:Catecholamines; D006371:Helium