[Is there a relation between weight in rats, bone density, ash weight and histomorphometric indicators of trabecular volume and thickness in the bones of extremities?].

Authors deal with question, if there is possibility to infer bone histological structure (described by histomorphometric parameters of trabecular bone volume and trabecular thickness) from bone density, ash weight or even from weight of animal (rat). Both tibias of each of 30 intact male rats, 90 days old, were processed. Left tibia was utilized to the determination of histomorphometric parameters of undecalcified bone tissue patterns by automatic image analysis.

[Effect of calcitonin on regional blood flow in bones, serum levels of IGF-I and osteocalcin, density and weight of bone ash in oophorectomized rats].

It is known that in cases of increased bone remodelation rate, i.e. after castration, local bone blood flow is also increased.

[Role of IGF-I and NO on regulation of regional blood circulation in the bones of rats].

Unlabelled: We present the results of two experiments aimed at the role of IGF-I and NO in the regulation of bone blood flow. In the first experiment A we determined the blood circulation in tibia and distal part of femur and the blood level of IGF-I after oophorectomy (OOX, 4 weeks before the experiment) and/or administration of NG-nitro-L-arginin methyl ester (L-NAME, Sigma, USA, 0.05% in the food for 10 days before the experiment).

[Effect of parathormone on bone blood flow in rats--possible role of NO].

Unlabelled: Parathyroid hormone (PTH)--besides its main osteotrophic action--exerts also vascular effect demonstrated formerly also in bones. The aim of the presented work was to verify this effect of PTH using the radioactive microsphere method and to ascertain simultaneously whether NO does participate or not in this effect of PTH. We performed two experiments which were arranged in the same way, as follows: group I--controls, group II--PTH, group III--L-NAME, group IV--L-NAME + PTH.

[Effect of pamidronate on bone blood flow and serum levels of IGF-I in sham-operated and oophorectomized female rats].

In our previous work [7] we demonstrated that the bisphosphonate pamidronate lowered the bone blood flow of non-castrated female rats and inhibited the increase in bone blood flow after oophorectomy (OOX). In this paper we present the results of two similar experiments but also with the estimation of IGF-I in blood. The blood flow in the bones of female rats was estimated by means of 85-Sr microsphere technique (NEN, USA), the blood level of IGF-I was ascertained with Rat IGF-I RIA Kit (DSL, USA).

[Duration of the effect of growth hormone on spongious bone].

The influence of duration of growth hormone action (length of history of acromegaly) upon acromegalic trabecular bone histology was followed in 28 biopted active acromegalics. The histology of trabecular bone was standardized by histomorphometric parameters. No statistically significant relation between length of acromegalic history and any of measured histomorphometric parameters (trabecular volume, trabecular thickness, absolute osteoid volume and osteoid surface) was found.

[Effect of growth hormone and other hormones on trabecular bone structure in acromegaly].

The influence of growth hormone upon trabecular bone remodelation is not definitely clear. The authors of this study compared static and dynamic histomorphometric data of bone patterns of 28 numbered group of acromegalics and 35 numbered group of healthy individuals. They correlated also levels of growth hormone, thyroxine, prolactin and testosterone in men with histomorphometric parameters in acromegalic patients.

[Effect of growth hormone on the structure of bone spongiosa in rats].

Changes in bone spongiosa, which follow after administration of growth hormone (GH) are described differently. Histomorphometrically processed value of bone trabecular volume is found higher or lower than normal. In this study, changes of rat bone spongiosa after administration of GH or bisphosphonate pamidronate were followed.

Effect of growth hormone and pamidronate on bone blood flow, bone mineral and IGF-I levels in the rat.

So far it is not known whether the growth hormone (GH) has an effect on the local blood circulation in bones. Using male rats we studied the local blood circulation in the tibia and the distal end of the femur (by means of the uptake of 85Sr-microspheres), the density and ash weight of the tibia, the urinary excretion of pyridinoline (PD) and deoxypyridinoline (DPD) as an indicator of bone resorption and the blood levels of IGF-I after the administration of human GH (4 mg/kg s.c.

[Relation between local blood flow and bone mineralization indicators in the tibia of female rats].

The results presented contribute to the still unclarified question of the role of bone blood flow in the metabolism and mineralization of the bone tissue. We investigated correlation relationships between 85Sr-microsphere uptake (in % dose per g) or local blood flow (in ml/min per g) and density or ash weight (in g per ml of bone tissue) in the tibia of female rats. In four experiments a total of 16 correlations was computed.

Effect of pamidronate on bone blood flow in oophorectomized rats.

In connection with the known inhibitive action of bisphosphonates on bone resorption we were interested in their possible influence on bone blood flow (BBF). We determined BBF (85Sr-microsphere uptake in the tibia, distal femur and diaphysis of femur), cardiac output, density and ash weight of the tibia, as well as 24-h incorporation of 45Ca and 3H-proline into the tibia. Pamidronate (Aredia, CIBA-Geigy, Switzerland) was administered to sham-operated or oophorectomized (OOX) female rats in doses of 0.

Possible participation of EDRF-NO in the hormonal regulation of bone blood flow in rats.

An increase in bone blood flow (BBF) was observed in rats after castration whereas a decrease in BBF occurred after oestradiol or testosterone. The possible participation of prostaglandins in these changes was demonstrated. The present results show that the endothelium-derived relaxing factor, i.

[DHEA: another hormonal modulator of bone blood flow in rats].

Dehydroepiandrosterone (DHEA) is a steroid with important effects on the bone tissue. We tried to check up if it influenced also the bone blood flow (similarly as estradiol and testosterone). We administered DHEA (Sigma) dissolved in dimethylsulphoxide s.

[The role of EDRF-NO in the regulation of bone blood flow in rats: inhibition with L-NAME].

EDRF-NO probably participates-besides the prostaglandins [3, 4]-in local circulatory changes in the bones of female rats with modified level of sex hormones; we could demonstrate it indirectly using methylene blue as a blocking agent [5]. In this paper, we present corresponding results of two experiments with NG-nitro-arginine methyl ester (L-NAME) as a substance blocking the production of endothelium derived relaxing factor, i.e.

[Further evidence of the role of prostaglandin on the effects of hormones on blood circulation in bones].

In a short communication we demonstrated the inhibitory affect of acetylosalicylic acid (ASA) on the increased bone blood flow and 45Ca and 3H-proline incorporation in oophorectomized (OOX) female rats. This finding suggested probable participation of prostaglandin. The aim of the present work was to confirm and extend the initial observation and to find out, whether the administration of ASA did not affect also the decrease in the bone blood flow after the administration of estradiol benzoate (EB).

Inhibitory effect of hydrocortisone on the blood flow and 45Ca and 3H-proline incorporation into bones of female rats.

We studied the effects of hydrocortisone as a possible regulatory factor of bone blood flow and metabolism. Local bone blood flow in the tibia, distal femur, lumbar vertebra and some soft tissues (using 85Sr-microspheres), as well as 45Ca and 3H-proline incorporation into the tibia, bone density and ash weight per ml of the tibia were measured in sham-operated and oophorectomized female rats in which the influence of hydrocortisone administration (0.004% diet for 5 weeks) was followed.

[Radionuclides in endocrinology diagnosis and experimental research].

In the article, a brief historical survey is presented of the utilization of radioactive isotopes in endocrinology and, in particular, in the 3rd Medical Clinic and Laboratory for endocrinology and metabolism. In the following, the results of our own work on the local circulation of blood in rats, its regulations and changes, are presented, i.e.

[A decrease in blood flow and incorporation of 45Ca and 3H-proline in the bones in pregnant female rats].

In the experiments on rats, the bone blood flow may be influenced by the deficiency as well by the administration of sex hormones. The aim of this work was to investigate the bone circulation (determined by means of 85Sr-microspheres, experiment A and B) and the incorporation of 45Ca and 3H-proline into the tibia (experiment C) in the last stage of pregnancy (from 18 to 21 days), i.e.

Blood flow and mineral content of the tibia of female and male rats: changes following castration and/or administration of estradiol or testosterone.

We studied changes in the local circulation and mineralization of the rat tibia under different experimental conditions. Four experiments were performed on a total of 155 female and male rats: after oophorectomy (OOX) or orchidectomy (ORX), after the administration of estradiol benzoate (EB, Agofollin Depot, 1 mg/rat once a week or 5 mg/kg body weight once every 5 days for 4 weeks), or after the administration of testosterone (T, Agovirin Depot, 25 mg/kg body weight once every 5 days for 4 weeks). We estimated 85Sr-microsphere uptake and blood flow in the tibia, density of the tibia, and ash weight per bone volume unit.

Relationships between local circulatory changes in the tibia and kidney of male and female rats after castration and administration of estradiol or testosterone.

The effects of castration and of the four weeks' administration of estradiol or testosterone on the blood circulation in the tibia and the kidney (expressed as the 85Sr-microsphere uptake values, which are not influenced by simultaneous changes in cardiac output) were studied in four experiments on a total of 147 rats (68 females, 79 males), relative weights being noted at the same time. 85Sr-microsphere uptake in the tibia rose markedly after castration in both males and females, fell after estradiol benzoate in intact females and intact and orchidectomized males and also fell after testosterone in intact and oophorectomized females and orchidectomized males. 85Sr-microsphere uptake in the kidney rose after castration only in males in experiments B; it fell after estradiol in orchidectomized males and fell after testosterone in intact females and males and in orchidectomized males.

[The effect of estradiol, norethisterone and testosterone on regional circulation and relative weight of the testes, ovaries and uterus in rats].

In nine experiments of 188 rats (85 males and 103 females), relative weight and local blood flow (with 85Sr-microspheres) was estimated in testes, ovaries and uterus after the administration of estradiol benzoate (Agofollin Depot 1 mg per rat or 5 mg per kg s.c. in time intervals of 3 to 7 days), norethisterone (Norethisterone tablets 0.

Possible participation of prostaglandins in the increase in the bone blood flow in oophorectomized female rats.

The aim of this study was to verify the possible role of prostaglandin (PG) in the increase in the bone blood flow of female rats after oophorectomy (OOX). In two experiments we determined blood flow in the tibia and distal femur (85Sr-microspheres) and 24-h incorporation of 45Ca and 3H-proline. Acetylosalicyclic acid (ASA, 0.

Interrelations between body weight, cigarette smoking and spine mineral density in osteoporotic Czech women.

This study was designed to assess the influence of body weight and cigarette smoking on vertebral bone mineral density in 241 osteoporotic and age matched 98 normal Czech women. The present study demonstrated that bone density and the frequency of atraumatic vertebral fractures was not related to the body weight. High body weight was not found to show any protective action on bone.

[Local blood circulation, uptake of 45Ca, 85Sr and 3H-proline and mineral levels in the tibia of female rats: comparison and changes after administration of estradiol].

After six weeks' administration of estradiol benzoate (Agofollin Depot, 1 mg s.c. once a week) we determined in the first part of 70 days old female rats the uptake of 85Sr-microspheres and local blood flow in the tibia, in the second part 24 hours' incorporation of 45Ca and 3H-proline and in the third part 2 hours' uptake of 85Sr, bone density and ash weight related to 1 ml of bone volume.

[Local blood circulation and bone mineral content in the bones of rats: the effect of castration, estradiol and testosterone in male and female rats].

Four experiments on 76 female and 79 male rats were performed in which we followed up the effect of four weeks' administration of estradiol benzoate (Agofollin Depot 1 mg per rat once a week or 5 mg per kg once every 5 days s. c.) and testosterone isobutyrate (Agovirin Depot 25 mg per kg once every 5 days s.