title: A comparison of chromium-51 and iron-59 for estimating erythrocyte survival in the cat.
abstract: Erythrocyte survival studies were conducted on eight, normal, healthy, 1-year-old male specific-pathogen-free cats using both chromium-51 and iron-59 simultaneously. The chromium-51 procedure gave a half-life value of 11.1 +/- 0.9 days. This was considerably lower than would be expected on the basis of the experimentally determined iron-59 erythrocyte survival time of 51.2 +/- 14.9 days. The results of this study indicated that there was considerable loss of the chromium-51 label in the cat other than that from senescence alone. An analysis of the chromium-51 disappearance curve indicated that there were two exponential disappearance rates for the chromium-51 label and, in the absence of cell death, approximately 67% of the label was lost with a rate constant of 0.02 per day and 33% was lost with a rate constant of 0.1 per day. An equation is presented which models the loss of chromium-51 label which could be used to calculate erythrocyte survival from a chromium-51 disappearance curve. Blood volume measurements, hemograms, bone marrow differential results, and iron kinetic values also were determined and the results presented. While a reasonable approximation of the erythrocyte life span could be made by correcting the chromium-51 values for losses other than senescence, the iron-59 procedure would be the preferred method in cats.
mesh_terms: D000818:Animals; D002415:Cats / Q000097:blood* / Q000378:metabolism; D002860:Chromium Radioisotopes / Q000378:metabolism; D004905:Erythrocyte Aging; D006207:Half-Life; D007504:Iron Radioisotopes / Q000378:metabolism; D007700:Kinetics; D008297:Male
chemical_list: D002860:Chromium Radioisotopes; D007504:Iron Radioisotopes