par Schoutens, André 
;Bergmann, Pierre ;Verhas, Michel
Référence American journal of physiology. Heart and circulatory physiology, 236, 1, page (H1-H6)
Publication Publié, 1979
;Bergmann, Pierre ;Verhas, Michel Référence American journal of physiology. Heart and circulatory physiology, 236, 1, page (H1-H6)
Publication Publié, 1979
Article révisé par les pairs
| Résumé : | This paper investigates further the relationship between the initial bone clearance of a bone-seeking radioisotope or labeled substance and the bone blood flow. The bone blood flow of rats was modified over the widest possible range of physiological values by heating and cooling their hindlimbs. Osseous blood flow was measured by the arteriolar trapping of labeled microspheres of 15 μm diameter injected into the left ventricle. The plasma clearances of 45Ca and 99m Tc by bone were measured 10 min after the IV injection of radiocalcium and of 99m technetium pyrophosphate. The extraction ratio for 45Ca over the 10-min interval (45Ca clearance/bone plasma flow) was 0.60 for low blood flows, 0.40 for blood flows at rest, and 0.25 for high values of flow. The data for 99m Tc were, respectively, 0.68, 0.34, and 0.22. Initial bone clearances of either substance should not be used to measure the increases in bone blood flow over the values at rest. |
