[Circulatory changes in the rat tibia in dietary calcium and vitamin D deficiency. Effects of age and sex]. / Obehové zmeny v holenní kosti potkanu pri deficitu kalcia a vitaminu D v potrave. Vliv stárí a pohlaví.

In previous experiments (4) we observed in laboratory rats after a low Ca content diet with no vitamin D a decrease of blood flow through bones. In this study we follow whether the effect of the deficit diet is influenced by age or sex of experimental animals. Tibia blood flow in rats is established by 85Sr-microparticles, bone density is estimated by weighing the bone under water. After 10 days of feeding by the deficit diet 85Sr-microparticles catchment in young males is decreased to 74% of that of controls, in young females to 61%, blood flow is decreased to 46% and 51% respectively. In older males after the diet the microparticles catchment is significantly decreased to 63%, blood flow is non-significantly decreased to 82% (as a result of higher cardiac output). In the category of older females the effect of deficient diet is not demonstrable as regards both microparticles catchment and blood flow. Bone density in preliminary experiment after 40 days of diet is significantly decreased in males of both age categories and in young females, in the main experiment after 10 days of diet it is decreased only in the categories of young males and females. From the results obtained in following the effect of diet deficient in Ca and vitamin D on density and local blood flow in tibia of rats can be concluded 1) that in this respect younger rats are more susceptible, 2) in the category of older males the effect is partly demonstrable in males, but not in females.

[Regional blood flow and uptake of 99mTc-MDP and 85Sr in the femur and tibia in rats: regional differences and mutual relations]. / Místní prutok krve, záchyt 99mTc-MDP a záchyt 85Sr ve stehenní a holenni kosti potkanu: místní diferenciace a vzájemné souvislosti.

We established blood flow (by means of 85Sr-microparticles) and 24 hours 99mTc-methylendiphosphonate (MDP) catchment and that of 85Sr (at different time intervals) in five portions of femur and 4 portions of tibia in rats. 1. We detected a marked differentiation in blood flow among all measured portions with the highest values in growth active distal femur metaphysis and proximal tibia metaphysis and with the lowest value in distal terminal tibia portion. 99mTc-MDP catchment is also highest in both metaphysis parts, and in the other parts it is differentiated similarly as the blood flow. 85Sr catchment in the early phase is very high in both metaphyses, but in several weeks it decreases to very low values; in the other parts the differences are small as well as the changes in the course of several weeks. 2. There is a considerable similarity in blood flow and 99mTc-MDP, in 85Sr catchment only high initial catchment in growth active metaphysis parts corresponds with blood flow. The time course of 99mTc-MDP and 85Sr catchment in the first hours after an intravenous injection is almost identical. The experiments showed great (up to 15-fold) local differences in blood flow among growth active and the other parts of femur and tibia in rats and a similar differentiation in 99mTc-MDP catchment, suggesting a certain relationship (but not quantitative dependency).