[Increased blood flow and incorporation of 3H-proline and 45Ca into the bones of female rats after oophorectomy]. / Vzestup prutoku krve a inkorporace 3H-prolinu a 45Ca v kostech potkaních samic po ooforektomii.

In the submitted experiment the authors investigated changes of the local circulation (by assessing retention of 85Sr microparticles) and incorporation of 3H-proline and 45Ca in bone of female rats following oophorectomy (OOX). Four weeks after OOX retention of 85Sr microparticles in % from 1 g tissue rises significantly in the tibia, distal epiphysis of the femur and in vertebrae (insignificantly in the metaphysis and calva); the blood flow in (1 min-1).kg-1 is significantly increased in the tibia and diaphysis of the femur (the differences are less significant as the scatter of values is greater). No differentiation was found in the circulatory response with regard to the content of compact and trabecular tissue in the tested bone or part of a bone. In the examined soft tissues after OOX no detectable changes of the local circulation were found. It appears thus that the local circulatory reaction after OOX is specific only for bony tissue. Twenty-four hour incorporation of 3H-proline and 45Ca into the tibia of female rats is significantly raised after OOX - along with a rise of circulatory values these changes are obviously part of the enhanced metabolic activity of bony tissue after OOX. The specific reaction of the local circulation in bones to oestrogen deficiency is a potentially significant aspect of their action.

[Reduced blood flow in bones in female rats after administration of estrogen]. / Pokles prutoku krve kostmi potkaních samic po estrogenu.

The authors submit the results of investigations of the action of oestrogens on the blood flow in bones and other tissues of female rats (by means of 85Sr microparticles) on the incorporation of 3H-proline and 45Ca into bone marrow and on bone density and weight of the ashes. Daily s.c. injections of oestradiol dipropionate (Agofollin Spofa, CSFR, 0.1 mg per 100 g) reduce the blood flow in the tibia already on the first days and significantly on the 9th day of administration. After four injections of oestradiol benzoate with protracted action (Agofollin Depot Spofa, 1 mg.s.c. once a week) the retention of 85Sr microparticles is significantly reduced in the distal epiphysis of the femur, in both terminal portions of the tibia and in vertebrae; the blood flow is significantly reduced in the distal epiphysis of the femur and in the proximal end of the tibia. Among various soft tissues where measurements were made only in the kidneys a significant drop of the local circulation was recorded. Twenty-four hour incorporation of 3H-proline and 45Ca into the tibia is significantly reduced after depot oestradiol benzoate. Under the same conditions an inconstant significant rise of bone density or weight of the ash per volume of bone was found. Oestrogen administration to female rats thus causes a drop of the local circulation in bones, in particular in trabecular tissue (among soft parts only in the kidneys) and at the same time a reduced formation of bone matrix and the process of mineralization. So far we are unable to explain the mechanism and impact of the observed reactions.

[Dual-photon densitometry of the lumbar spine. Further experience and findings]. / Dvoufotonová denzitometrie bederní pátere. Dalsí zkusenosti a poznatky.

The authors submit further experience with two-photon absorption measurement of the mineral content of the lumbar spine using a NOVO/Lab BMC 22a (Denmark) apparatus. 1. The authors discuss the problem of evaluation of results in postmenopausal women. For the basic evaluation the authors use the range +/- 2 s of "normal" values classified by decades; another suitable guide to the interpretation could be extrapolation of the lower range of the regression zone in recorded in premenopausal women to higher age groups. 2. The histogram of frequencies of normal values in women in g.cm-2 has two peaks corresponding to the group of premenopausal women and the group of postmenopausal women. 3. Of 573 examined patients with osteoporosis 295, i. e. 51.5%, cannot be reliably evaluated or cannot be evaluated at all (as a rule because of changes of the spine). Of 49 results obtained in men with osteoporosis 34.7% are within the normal range, of 229 results obtained in women with osteoporosis 47.2% are within the normal range. The hitherto assembled experience is consistent with the view that the method is useful and invaluable in particular for the long-term follow up of patients.

[The effect of calcium and vitamin D deficiency in the food on the uptake and retention of 99mTc-methylenediphosphonate and 85Sr in the bones in rats]. / Ucinek deficitu kalcia a vitaminu D v potrave na záchyt a retenci 99mTc-metylendifosfonátu a 85Sr v kostech potkanu.

The effects of vitamin D-free diet with low Ca content on 24 hours' 99mTc-methylendiphosphonate retention (in the whole body and tibia), long-term the whole body 85Sr retention and 2 hours' 85Sr catchment in epiphysis, metaphysis and diaphysis of femur and tibia in rats (at the same time in certain experiments femur density and weight after incineration were established) were followed. The whole body 99mTc-MDP retention increases significantly as early as the third day of the diet administration, retention in tibia and the whole body is in further 2 experiments increased after 1, 2 and 4 weeks of the diet (density decreases from the first or the second week). The whole body 85Sr retention is significantly increased as early as after 2 days of the diet, the great difference against controls only slowly decreases after discontinuation of low-Ca diet. Further experiment followed 2 hours' 85Sr catchment in femur and tibia samples after 2, 5, 10 and 20 days of diet--catchment increase is significant after 20 days (bone density and ash weight is significantly decreased after 10 and 20 days of diet). Thus retention of both osteotrophic substances in bone is as a result of low Ca diet increased. This reaction is in case with 85Sr expected, in that of 99mTc-MDP it suggests a possible relation of the catchment and mineral component of osseous tissue. Increased retention of both the substances obviously fails to be related to local blood circulation which was in this situation in our previous experiments decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

[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).

[Additional observations on age differences in the blood circulation in rats]. / Dalsí poznatky k vekovým rozdílum v krevním obehu krys.

By means of microparticles labelled by radioactive strontium 85Sr (3M, USA) the authors in two experiments established cardiac output and local blood flow through bones and certain other organs and tissues of rats in two distinct age categories (35 and 90 days, 45 and 110 days). The results of both experiments showed 1) significant decrease of blood flow in skull, lumbar vertebrae, distal epiphysis, distal metaphysis and thighbone diaphysis and tibia in older rats of both sexes (proof of previous results with 86Rb), 2) constantly significant decrease of blood flow through a skin sample taken from the ventral side of the trunk and 3) nonconstant increase of blood flow through kidneys of older rats. The causes of observed changes are not known, physiological importance to be supposed particularly as regards the circulatory changes in bones, is also not clear.

[The effect of oophorectomy on blood flow, 85Sr uptake and mineral content in the tibia of female rats]. / Ucinek ooforektomie na prutok krve, záchty 85Sr a obsah minerálu v holenních kostech potkaních samic.

The authors investigated in three experiments the blood flow (by retention of 85Sr microparticles), the 85Sr retention and state of mineralization of the tibia in female rats after oophorectomy (OOX). In the first experiment one month after OOX the retention of 85Sr microparticles is increased significantly to 158.6%, as compared with controls, the blood flow is increased insignificantly to 131.3%. In the second experiment the retention of microparticles is increased maximally 4 weeks after OOX to 152.9%, the blood flow after two weeks to 150.0%, as compared with controls; the weight of the ash per unit of bone volume of the tibia is significantly reduced after 8 weeks following OOX--to 90.8%. The two-hour retention of radioactive strontium 85Sr in the third experiment after OOX rises--significantly after 8 weeks to 133.4%. The results of the experiments are consistent with the idea on an increased metabolic activity of osseous tissue in the initial stage of the demineralization process following OOX.

[Additional findings on age differences in the blood circulation in rats]. / Dalsí poznatky k vekovým rozdílum v krevním obehu krys.

By means of microparticles labelled by radioactive strontium 85Sr (3M, USA) the authors in two experiments established cardiac output and local blood flow through bones and certain other organs and tissues of rats in two distinct age categories (35 and 90 days, 45 and 110 days). The results of both experiments showed 1) significant decrease of blood flow in skull, lumbar vertebrae, distal epiphysis, distal metaphysis and thighbone diaphysis and tibia in older rats of both sexes (proof of previous results with 86Rb), 2) constantly significant decrease of blood flow through a skin sample taken from the ventral side of the trunk and 3) nonconstant increase of blood flow through kidneys of older rats. The causes of observed changes are not known, physiological importance to be supposed particularly as regards the circulatory changes in bones, is also not clear.

[The effect of age and sex on bone retention of radioactive strontium 85Sr in rats]. / Vliv stárí a pohlaví na kostní retenci radioaktivního stroncia 85Sr u krys.

Retention of radioactive strontium 85Sr (18,5 kBq i.e. 0.5 microCi i.p.)--concerning the whole body and in distal epiphysis, distal metaphysis and in the thigh bone diaphysis--was followed up in two similar experiments for the period of 5-6 weeks in rats of both sexes and different age (younger category 40-45 days, older category 120-140 days). In both experiments bone retention 85Sr in older female rats is lower than in younger female rats. In male rats similar difference has not been constantly proved. Retention seems to be higher in female rats in comparison with males in the category of young rats. On the contrary in the category of older rats the retention is lower in female rats. In epiphysis and diaphysis of the thigh bone the differences are analogous to whole body differences; 85Sr reacts in the opposite way in distal metaphysis--retention is here extensively higher in older rats than in younger ones. The results obtained confirm the conclusion interesting from the point of view of clinical problem: avidity of the skelet to administered radioactive strontium is in younger female rats higher than in young male rats. However it is severely declining especially in female rats--in the second experiment as far as the level significantly lower than in male rats of the same older age category.

[Dual-photon densitometry of the lumbar spine. Basic experience and results]. / Dvoufotonová denzitometrie bederní pátere. Základní zkusenosti a výsledky.

The principle of assessment of absorption of gamma radiation (single photon radiation, i.e. with one radiation energy) was first applied to assess the content of mineral substances in peripheral bones. Earlier and more marked affection of the spine in osteoporosis led to the development of dual-photon densitometry, i.e. differential assessment of the absorption of gamma radiation with two energies, which makes it possible to eliminate the ratio of soft tissues in absorption of the radiation (the source of radiation is gadolinium 153Gd). The equipment is more complicated and more expensive, the operation more time consuming and more pretentious. Various circumstances - most frequently changes of the spine with foci of increased density - make it difficult or impossible to evaluate and use the results in one third of patients with disorders of the bones (most frequently osteoporosis), incl. 1/2 of the patients above 60 years of age. Short-term reproducibility of the estimations is satisfactory - variation coefficients of repeated measurements in g.cm-1 and in g.cm-2 are less than 2%. Examination of 183 controls (83 men, 100 women) indicates a drop of the mineral content in L2 to L4 with age in women from 25 to 30 years to old age with a slight acceleration during the menopause, in men a decline only after the age of 60 years. In younger age groups the scatter of our normal values in men is greater than in women. The bone density in g, g.cm-1 as well as in 9.cm-2 rises significantly in the order L2 less than L3 less than L4. Except for the limited applicability of results the basic experience is on the whole favourable. From the clinical aspects the evaluation of pathological findings, to which a separate paper will be devoted, is of decisive importance.

Decreased 133Xe clearance in the proximal femur in acromegaly.

Using the 133Xe tissue clearance method, the blood flow in the greater trochanter of the femur was studied in 30 patients with acromegaly. Both the washout rate constant (k2) and blood flow (P2) values are significantly decreased in acromegaly (p less than 0.01). There is a significant negative correlation (r = -0.42, p less than 0.05) between the flow values and mean daily concentrations of growth hormone in serum of acromegalic patients. The observations is presented as a preliminary evidence of a possible influence of growth hormone on the blood flow in bone.