Short-term distribution of Cs in relation to Cr-EDTA after intravenous dose in goats.
OBJECTIVE
The aim of this study was to gather information about the short-term rate of caesium uptake (incorporation) in different animal tissues and explain them with known physiological mechanisms affecting ion distribution.


METHODS
Six goats were given an intravenous bolus containing (134)Cs as a tracer and (51)Cr-EDTA as an extracellular marker. After 30 min, the animals were killed and the activity concentration of radioactive isotopes in different tissues and fluid compartments were measured.


RESULTS
The highest relative activity concentration of (134)Cs was found in kidney cortex, with a tissue/plasma-ratio around 50. In urine, the ratio varied between 5 and 28. In the salivary gland, cardiac muscle and small intestine the ratio was around 11, 7 and 6, respectively. The contents of small intestine had an average activity concentration five times that of plasma. In skeletal muscle the terminal activity concentration was surprisingly low, with a tissue/plasma ratio mostly far less than unity. Even in connective tissue and cartilage the terminal activity concentration was generally higher than in skeletal muscle.


CONCLUSIONS
The rate of uptake of caesium varies widely from tissue to tissue. Many of these differences can be explained with differences in Na,K-ATPase activity. Also, perfusion and accessibility play a role in some tissues, like brain and possibly part of the skeletal muscles. The short-term distribution of caesium differs distinctly from the long-term distribution reported in literature.
Kaikkonen
M
M
Department of Basic Veterinary Sciences, PO Box 66, University of Helsinki, FIN-00014 Helsinki, Finland.
de Gritz
B
B
Eriksson
L
L
D000818:Animals; D002588:Cesium Radioisotopes / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002860:Chromium Radioisotopes / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics; D004492:Edetic Acid / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D045604:Extracellular Fluid / Q000378:metabolism; D005260:Female; D006041:Goats; D007275:Injections, Intravenous; D007672:Kidney Cortex / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology; D014018:Tissue Distribution
D002588:Cesium Radioisotopes; D002860:Chromium Radioisotopes; D004492:Edetic Acid; D000254:Sodium-Potassium-Exchanging ATPase