Comparing the Healing Abilities of Fluorapatite and Hydroxyapatite Ceramics in Regenerating Bone Tissue: An In Vivo Study.

Some reports in the literature show the advantages of fluoride-containing apatite ceramics over hydroxyapatite (HAP), at least in some aspects. While HAP has been used extensively in the treatment of bone defects, fluoridated apatite has hardly been tested in vivo. In order to verify the biological properties of fluoride-doped apatite and to assess its therapeutic potential, we synthesized fluorapatite (FAP) and applied it as a filling in bone defects of experimental animals (rabbits). The treatment effects were evaluated on extracted bones after 3 and 6 months from implantation using peripheral quantitative computed tomography (pQCT), dual-energy X-ray absorptiometry (DXA), radiography (X-ray) and histological staining. The study proved the integration between FAP and the bone tissue, thus indicating its stimulating effect on new bone formation and mineralization. The results achieved after 3 months of treatment were difficult to interpret unequivocally and suggested the transient delay in FAP integration of bone in comparison with HAP. The reasons for this phenomenon are unclear. Most likely, these differences between FAP and HAP resulted mainly from the different porosities, densities and ionic reactivity of the ceramics, which in our opinion affected their solubility, integration and degree of bone tissue resorption. However, it was shown that 6 months after implantation, similar level of bone defect regeneration was achieved for both FAP and HAP. In this article, we present our hypothesis concerning the basis of this phenomenon.

Osteotropic Effect of Parenteral Obesity in Programmed Male Rats Fed a Calorically Differentiated Diet during Growth and Development.

The experiment was undertaken to assess whether the continuation or change of the parents' diet affects the previously programmed bone metabolism of the male offspring during its growth and development. A total of 16 male and 32 female Wistar rats were divided into groups and fed a standard (diet S) or high-energy (diet F). After the induction of obesity, the rats from groups S and F, as the parent generation, were used to obtain male offspring, which were kept with their mothers until the weaning day (21 days of age). In our earlier study, we documented the programming effects of the diet used in parents on the skeletal system of offspring measured on the weaning day. Weaned male offspring constitute one control group-parents and offspring fed the S diet. There were three experimental groups, where: parents received diet S and offspring were fed with the F diet; parents were treated with the diet F, while offspring received the S diet; and parents and offspring were fed with the diet F. The analyses were performed at 49 and 90 days of life. After sacrifice, cleaned-off soft tissue femora were assessed using peripheral quantitative computed tomography (pQCT), dual X-ray absorptiometry (DXA), and a three-point bending test. We observed that changing and continuation of nutrition, applied previously in parents, significantly influenced the metabolism of the bone tissue in male offspring, and the osteotropic effects differed, depending on the character of the nutrition modification and age. Additionally, an important conclusion of our study, regarding the previous, is that nutrition modification, affecting the metabolism of bone tissue, also depends on the sex.

When Incorporated into Fruit Sorbet Matrix, Are the Fructans in Natural Raw Materials More Beneficial for Bone Health than Commercial Formulation Added Alone?

We assessed the extent to which fructans from various sources and added in various forms (raw materials in diet alone or incorporated into a strawberry matrix) differ in their effectiveness towards selected parameters related to bone health under calcium hypoalimentation in growing female Wistar rats. The aim of this study was to evaluate the levels of selected parameters involved in calcium metabolism, in response to a 12-week restriction of Ca intake: serum ions (Ca, Mg, P); the activity of alkaline phosphatase-using a BS 120 analyzer; the markers of bone turnover (osteocalcin, CTX; using a Rat-MidTMOsteocalcinEIA Kit and RatLapsTMEIA, respectively); and the bone mineral content (BMC) and density (BMD), using a Norland Excell Plus Densitometer. Among the examined markers, the CTX concentration increased dramatically under calcium hypoalimentation. The presence of Jerusalem artichoke (independently of the form of addition) and yacon root powder (with strawberry sorbet matrix) in the rats' diet led to a significantly lower CTX concentration than was observed in the low-calcium control group. The type of fructan influenced the bone mass content. When fructan was added to the low-calcium diet as an ingredient of sorbet, it exerted more pronounced effects on the biochemical parameters of bone metabolism than when added alone, in the growing-female-rat model.

The Influence of Nesfatin-1 on Bone Metabolism Markers Concentration, Densitometric, Tomographic and Mechanical Parameters of Skeletal System of Rats in the Conditions of Established Osteopenia.

Our study aimed to evaluate the impact of nesfatin-1 administration on bone metabolism and properties in established osteopenia in ovariectomized female rats. In total, 21 female Wistar rats were assigned to two groups: sham-operated (SHAM, n = 7) and ovariectomized (OVA, n = 14). After 12 weeks of osteopenia induction in the OVA females, the animals were given i.p. physiological saline (OVA, n = 7) or 2 µg/kg body weight of nesfatin-1(NES, n = 7) for the next 8 weeks. The SHAM animals received physiological saline at the same time. Final body weight, total bone mineral density and content of the skeleton were estimated. Then, isolated femora and tibias were subjected to densitometric, tomographic, and mechanical tests. Bone metabolism markers, i.e., osteocalcin, bone specific alkaline phosphatase (bALP), and crosslinked N-terminal telopeptide of type I collagen (NTx) were determined in serum using an ELISA kit. Ovariectomy led to negative changes in bone metabolism associated with increased resorption, thus diminishing the densitometric, tomographic, and mechanical parameters. In turn, the administration of nesfatin-1 led to an increase in the value of the majority of the tested parameters of bones. The lowest bALP concentration and the highest NTx concentration were found in the OVA females. The bALP concentration was significantly higher after nesfatin-1 administration in comparison to the OVA rats. In conclusion, the results indicate that nesfatin-1 treatment limits bone loss, preserves bone architecture, and increases bone strength in condition of established osteopenia.

The programming effect of parenteral obesity on the structural and mechanical properties of femora in female rats fed a varied calorie diet during puberty.

The study was aimed to ascertain whether continuation or change in the offspring of the diet consumed by the parents modulates, in later life, the previously programmed bone metabolism. We used adult Wistar rats (16 males; 32 females), divided into groups that were fed either a standard (diet S) or a high-energy (diet F). After 90 days of obesity induction, the rats were submitted to obtain female offspring from parents S and F. The offspring stayed with their mothers until 21 days of age (weaning day). Our previous studies have proved the programming effects of parental obesity on the skeletal system of their offspring at the age of 21 days. Weaned female offspring were divided into groups: S/S-parents and offspring fed the S diet; S/F-parents fed the S diet and offspring fed the F diet; F/S-parents fed the diet F and offspring with the diet S; F/F-parents and offspring fed the F diet (F/F). After sacrifice, isolated femurs were assessed by peripheral quantitative computed tomography and by a three-point bending test. The bones were examined at 49 and 90 days of life. We found that nutritional programming has a significant influence on the development and metabolism of the skeletal system in females during growth and maturity. Moreover, the modification of nutrition alters the metabolism of bone tissue, and the osteotropic effects vary depending on the nature of the change, as well as the stage of development. Reducing the caloric content of the diet inhibits the mineralization and decreases the mechanical strength of the bones while increasing the caloric content of the diet has a beneficial osteotropic effect.

Lipoic acid (LA) dose-dependently protects bone losses in the mandible of rats during the development of osteopenia by inhibiting oxidative stress and promoting bone formation.

Our study was carried out to evaluate the effect of lipoic acid (LA) on the densitometric properties, structure and mechanical strength of the mandible of Wistar rats with developing osteopenia. The study used 42 sham-operated (SHO) and ovariectomized (OVX) rats. The OVX rats were randomly divided (n = 6) onto two controls treated subcutaneously with physiological saline (OVX-PhS) and 17ß-estradiol (OVX-E2), respectively, and onto four experimental OVX groups that received LA in the doses of 12.5, 25, 50 and 100 mg/kg/day for 28 days. The results demonstrated that the lack of estrogen brought about osteopenic bone changes, especially in the trabecular compartment. In addition, while the usage of LA in the doses of 12.5 and 25 LA had no effect in OVX rats, the dose of 100 effectively inhibited osteopenic changes of the mandible. This dose maintained structural, densitometric and mechanical parameters at levels like that in the SHO and OVX-E2 groups by inhibiting the destructive influence of oxidative stress. Dose 50, however, was revealed to be the most effective. It not only inhibited atrophic changes and the influence of oxidative stress, but also stimulated the formation of mandibular bone tissue. Our results suggest that the administration of LA is effective in preventing atrophic changes in the mandibular bone tissue in conditions of ovarian hormone deficiency and suggest its potential in the therapy of osteoporosis.

Camelina Oil Supplementation Improves Bone Parameters in Ovariectomized Rats.

The aim of the present study was to determine the effect of administration of Camelina sativa oil (CO) as a source of polyunsaturated fatty acids (PUFA) on bone parameters in ovariectomized rats (OVX). Overall, 40 10-week-old healthy female Wistar rats were divided into 4 groups with 10 animals in each. Rats in the control group (SHO) were subjected to a sham operation, whereas experimental rats (OVX) were ovariectomized. After a 7-day recovery period, the SHO the rats received orally 1 mL of physiological saline for the next 6 weeks. The OVX rats received orally 1 mL of physiological saline (OVX-PhS), 5 g/kg BW (OVX-CO5), or 9 g/kg BW (OVX-CO9) of camelina oil. The use of camelina oil had a significant effect on body weight, lean mass, and fat mass. The camelina oil administration suppressed the decrease in the values of some densitometric, tomographic, and mechanical parameters of femur caused by estrogen deficiency. The CO treatment increased significantly the serum level of osteocalcin and decreased the serum level of C-terminal telopeptide of type I collagen in the OVX rats. In conclusion, camelina oil exerts a positive osteotropic effect by inhibiting ovariectomy-induced adverse changes in bones. Camelina oil supplementation can be used as an efficient method for improving bone health in a disturbed state. However, further research must be carried out on other animal species supplemented with the oil.

Programming Effect of the Parental Obesity on the Skeletal System of Offspring at Weaning Day.

Our study aimed to verify the hypothesis of the existence of a programming effect of parental obesity on the growth, development and mineralization of the skeletal system in female and male rat offspring on the day of weaning. The study began with the induction of obesity in female and male rats of the parental generation, using a high-energy diet (group F). Females and males of the control group received the standard diet (group S). After 90 days of dietary-induced obesity, the diet in group F was changed into the standard. Rats from groups F and S were mated to obtain offspring which stayed with their mothers until 21 days of age. Tibia was tested using dual-energy X-ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), micro-computed tomography (µCT) and mechanical strength using the three-point bending test. Biochemical analysis of blood serum bone metabolism markers was performed. DXA analysis showed higher tibia bone mineral content (BMC) and area. pQCT measurements of cortical and trabecular tissue documented the increase of the volumetric bone mineral density and BMC of both bone compartments in offspring from the F group, while µCT of the trabecular tissue showed an increase in trabecular thickness and a decrease of its separation. Parental obesity, hence, exerts a programming influence on the development of the skeletal system of the offspring on the day of the weaning, which was reflected in the intensification of mineralization and increased bone strength.

Experimental Phage Therapies in Companion Animals with A Historical Review.

BACKGROUND: The aim of the review was to comprehensively characterize the antimicrobial efficacy of bacteriophages in eliminating pathogens occurring in companion animals, as an alternative to antibiotics for controlling infections that pose potential threats to the health and life of people and to the environment. METHODS: The review contains detailed information on the characteristics and classification of bacteriophages and an analysis of their life cycle. The dominant element is a detailed analysis of the experimental use of bacteriophages in combating infections caused by various microorganisms in companion animals with regard to their potential use in therapy. RESULTS: It seems that in the near future, phage therapies will provide an alternative to antibiotics in the treatment of diseases caused by multi-drug resistant bacteria in people and animals. CONCLUSIONS: The effectiveness of phage therapies depends on many factors and the properties of the bacteriophages themselves, which requires comprehensive knowledge of them.

Molecular detection of Anaplasma phagocytophilum in roe deer (Capreolus capreolus) in eastern Poland.

Wild ungulates may serve as reservoirs for particular tick-borne pathogens (TBP) of importance for public and animal health. The aim of the study was to investigate, for the first time, the occurrence of Anaplasma phagocytophilum (AP) in a large population of roe deer in eastern Poland. Spleen samples from 424 roe deer (Capreolus capreolus) were collected during the 2018-2019 hunting season. Genetic screening for AP was carried out by PCR amplification of a fragment of the 16S rRNA and groEL genes. Twenty-six of the 424 spleen samples (6.13%) tested positive both for 16S rRNA and groEL. Phylogenetic analysis confirmed the existence of a specific roe deer ecotype of AP in eastern Poland. Despite the low prevalence of AP in roe deer populations in the study area, these animals may act as anaplasmosis reservoirs for ticks. Based on the zoonotic potential of granulocytic anaplasmosis, it seems advisable to introduce continuous monitoring of this infection among domestic, farm and wild animals.

Bone losses in obese, ovariectomized rats appear to be independent from sclerostin-induced inhibition of the Wnt/ß-catenin pathway.

INTRODUCTION: Overweight and obesity, as well as a gonadal function, are pivotal factors influencing bone tissue metabolism. MATERIAL AND METHODS: The aim of the study was to determine the effect of dietary induced obesity (DIO) on bone tissue metabolism in sham-operated (SHO) or ovariectomized (OVX) adult female Wistar rats. Additionally, the influence of DIO in SHO or OVX on the concentration of sclerostin in the blood serum was analyzed. After SHO or OVX, the rats were placed in groups (n=8) and either received a standard diet (11.5 MJ/kg) (SHO-CON; OVX-CON) or a high-energy diet (17.6 MJ/kg) (SHO-FAT; OVX-FAT). The experiment lasted for 90 days and allowed for the establishment of osteopenia in OVX females and obesity in the rats that had received the high-energy diet. RESULTS: The results of the study demonstrate that obesity or/and ovariectomy increases the resorption of femora and tibiae, hence decreasing the densitometric and mechanical parameters affecting the bone structure in adult females rats. The strongest osteodegenerative effect was seen in the OVX-FAT females. Interestingly, the degree of bone tissue degradation caused exclusively by ovariectomy was similar to that found in the obese sham-operated rats. CONCLUSIONS: Bone losses invoked by DIO seem to be independent from the Wnt/ß-catenin pathway inhibition induced by sclerostin. While further study is necessary, the obtained results suggest that the usage of sclerostin anti-body in the treatment of osteoporosis can be ineffective, and in obese patients the undertaking of such therapy should be reassessed.

The effect of fructan-enriched diet on bone turnover parameters in ovariectomized rats under calcium restriction.

INTRODUCTION: Osteoporosis, the "quiet epidemic", is one of the most serious threats to public health. It is known that estrogen plays a significant role in the regulation of bone turnover, and its loss at menopause causes osteoporosis. Added to this, insufficient calcium intake accelerates bone mass loss, increasing the risk of fractures. OBJECTIVE: The study aimed to answer the question whether a fructan-enriched diet could be helpful in preventing from disturbances in bone turnover caused by calcium restriction combined with ovariectomy-induced estrogen deficiency. The differences related to the kind of fructan and 'matrix effect' of fructan action (form of addition) were also evaluated. MATERIAL AND METHODS: The study was conducted using sham-operated (control groups) or ovariectomized (OVX) rats fed a calcium restricted diet. The treatment diets contained one of three fructan sources - Jerusalem artichoke, yacon and Beneo Orafti Synergy1 - added alone or as an ingredient of strawberry sorbet, all in the amount providing 8% fructans. Analyses of biological material included: serum Ca, Mg and P concentrations, alkaline phosphatase activity (ALP), osteocalcin (OC) and C-telopeptide degradation products from type I collagen (CTX). Densitometric parameters of femora were also assayed. RESULTS: Among markers of bone turnover, the ALP activity depended both on the kind of fructan and the form of addition. The highest value was shown in the OVX group fed a low-calcium diet, whereas administration of diet enriched with Jerusalem artichoke led to an almost 50% decrease in the value of this parameter. Dietary fructans also lowered the OC level. Feeding rats with diet containing sorbet enriched in yacon or Jerusalem artichoke resulted in a decrease of CTX, compared to the diet containing yacon alone or fructan formulation in both forms No significant differences were observed in densitometric parameters between treatment groups. CONCLUSIONS: The obtained findings suggest that fructan administration with a calcium-restricted diet might exert a positive effect on bone turnover parameters. Regarding the form of their addition, it is possible that other constituents of sorbets contributed to the fructan action. It remains open whether this impact would be significant over a longer period of time.

Could fructan sources in strawberry matrix be more effective as a tool for improvement of bone structure than these compounds added to diet alone? - Study on osteopenic rat model.

INTRODUCTION: Osteoporosis, a disease associated with ovarian hormone deficiency following menopause, is the most common cause of age-related bone loss. Although an optimal intake of Ca is vital - both bone accretion during growth and maintenance in adult life - a great percentage of the population consumes far below the recommended amounts of this mineral. On the other hand, there are evidences that fructans enhance not only Ca absorption, but bone calcium as well. OBJECTIVE: In the knowledge that estrogen deficiency and insufficient Ca in the diet during postmenopause cause serious problems with resultant osteoporosis, the aim of this study is to assess the effects of a diet enriched in fructan-containing sources alone, or in the "strawberry matrix", on the structure of bone in OVX rats under calcium hypoalimentation. MATERIAL AND METHODS: Experimental animals were female Wistar rats, sham-operated or ovariectomized. The treatment with Ca-restricted diets also contained one of the sources of fructan (Jerusalem artichoke, yacon, Beneo Orafti Synergy1), in the amount providing 8% of fructans. Femur architecture of rats was assessed by tomography and Ca content by the AAS method. RESULTS: Ovariectomy led to a significant decrease in femoral Ca content, total mineral content and bone density of rats. This study shows that a diet containing inulin-type fructan (especially as a component of strawberry product) improved bone quality (i.e. increase in Ca content in femur, total density in middle part of bone, as well as decrease of endosteal circumference) in OVX rats under calcium hypoalimentation. CONCLUSIONS: These findings suggest that a fructan-enriched diet could be potentially useful for postmenopausal osteoporosis. It is important to determine an optimal dietary level of fructan with the long-term goal of developing a dietary strategy in osteoporosis prevention.

Nesfatin-1 prevents negative changes in bone in conditions of developing osteopenia.

OBJECTIVE: The aim of the study was to determine the effect of nesfatin-1 on bone properties in female rats in the conditions of developing osteopenia induced by ovariectomy (OVX). MATERIAL AND METHODS: The experiment was performed on 21 female Wistar rats assigned to 3 groups receiving intraperitoneally physiological saline (SHO, OVX-PhS) and nesfatin-1 in dose 2 µg/kg BW of (OVX-NES) once a day for 8 wks. At the end of the experiment, the rats were scanned using the DXA method to determine the body composition, tBMC, and tBMD. The isolated femora and tibia were tested with the DXA method for BMD and BMC, and with the pQCT method for separate analysis of the cortical and trabecular bone tissue. The bone strength parameters were also determined. The immunohistochemical method was used for determination of nesfatin-1 localization in growth cartilage. Bone metabolism markers (osteocalcin, bALP, and NTx) were identified using an ELISA kit. RESULTS: OVX exerts a negative effect on bone tissue. The nesfatin-1 administration influenced positively the DXA parameters of tibia. TvBMD and TbvBMD measured by pQCT in metaphysis of bones were significantly higher in the OVX-NES group than in OVX-PhS. No differences were found in the values of bone strength parameters between SHO and OVX-NES females. Extra- and intracellular immunohistochemical reaction for nesfatin-1 was observed in all zones of growth cartilage, with the strongest reaction detected in the calcifying zone. Nesfatin-1 administration caused a significant increase in the osteocalcin and bALP concentration in relation to the OVX-PhS animals. CONCLUSIONS: The results of the experiment indicate that nesfatin-1 exerts a protective effect on bone tissue properties and can be used in the prevention of osteoporosis.

Novel insights into the relationship between nonalcoholic fatty liver disease and osteoporosis.

Excess fat deposition and insulin resistance are considered the main risk factors for nonalcoholic fatty liver disease (NAFLD), and therefore, not surprisingly, the global prevalence of NAFLD increases in parallel with both obesity and type 2 diabetes. Although deterioration of bone homeostasis in patients with NAFLD is commonly observed, its etiology has not been fully elucidated yet. It was shown in several studies that bone tissue seems to be independently associated with NAFLD. A mechanistic perspective puts the liver at the center of mutual interdependencies obviously involving adipose tissue and muscles and also the bone matrix and bone cells, which are relatively novel. In this review, various pathophysiological mechanisms and possible mediating molecules that may interplay between NAFLD and bone tissue are described. Chronic inflammation, vitamin D3, growth hormone, insulin-like growth factor 1, osteopontin, fetuin-A, irisin, osteocalcin, and osteoprotegerin from osteoblasts have been proposed as mediators of mutual interactions among the skeleton, fatty tissue, and liver. Although to date there are still many issues that have not been elucidated, growing evidence suggests that screening and surveillance of bone mineral density in patients with NAFLD should be considered in future strategies and guidelines for NAFLD management.

Application of Platelet-rich Plasma and Tricalcium Phosphate in the Treatment of Comminuted Fractures in Animals.

AIM: To assess the applicability of ß-tri-calcium phosphate (TCP) and platelet-rich plasma (PRP) in the treatment of comminuted fractures in small animals. MATERIAL AND METHODS: The experimental study was carried out on 16 New Zealand White rabbits. After creating the bone defect and performing tibial osteotomy, TCP implants containing activated PRP were introduced into the fracture and the defect. The fracture was stabilised using external fixators or intramedullary nails. After 12 weeks, the animals were euthanised, and radiological, histological, scanning electron microscopy and peripheral quantitative computed tomography examinations were performed. The analysis also covered the results of fracture treatment in 37 small animals (cats and dogs) in which treatment with TCP containing PRP was used as an alternative to cancellous bone implantation. RESULTS: Correct bone union was observed in the experimental groups, TCP remained visible at the site of the fracture after 12 weeks. In the clinical application in small animals, bone union was observed in over 91% of treated animals. CONCLUSION: ß-TCP and activated PRP may be an effective method of bone union enhancement in the treatment of comminuted fractures in small animals.

Fructan-Enriched Diet Increases Bone Quality in Female Growing Rats at Calcium Deficiency.

This study was designed to determine the effect of feeding female rats with low-calcium diet containing one of three fructan sources (Jerusalem artichoke, yacon, Beneo Orafti Synergy1), on selected bone parameters. Growing Wistar rats were fed modified AIN-93 G diet enriched in fructan sources (8%), added alone or as a strawberry sorbet ingredient. Two of eight groups were a validation model, where the positive control group was fed with recommended calcium dose in the diet (RCD), and negative one - with low calcium diet (LCD). After 12 weeks, femoral Ca content, bone densitometry, architecture and hardness were examined. The positive effects on femoral Ca content and cortical thickness, area and content in distal part of bone was observed after feeding animals diet enriched in Jerusalem artichoke sorbet. Beneficial action on other bone tomographic parameters (particularly trabecular volumetric bone mineral density) in this part of femur were associated mainly with the consumption of the diet with sorbet containing yacon. Our results showed an important role of diet containing frozen strawberry desserts enriched in fructan sources in the maintenance of healthy bones of growing organism. It may suggest possible synergisms between fructans and bioactive substances of strawberry.

The peripheral quantitative computed tomographic and densitometric analysis of skeletal tissue in male Wistar rats after chromium sulfate treatment.

INTRODUCTION: This study evaluates the effects of three different doses of chromium sulphate on bone density and the tomographic parameters of skeletal tissue of rats. MATERIAL AND METHODS: The experiment was performed on 40 male Wistar rats which received, by gavage, during 90 days, a chromium sulphate in either a daily dose of 400, 600 or 800 µg/kg BW. At the end of experiment, the rats were scanned using the densitometry method (DXA) to determine the bone mineral density, bone mineral content of total skeleton and vertebral column (L2-L4) and parameters of body composition (Lean Mass and Fat Mass). The isolated femora were scanned using peripheral a quantitative computed tomography method (pQCT) for a separate analysis of the trabecular and cortical bone tissue. The ultimate strength, work to ultimate and the Young modulus of femora was also investigated by the three-point bending test. RESULTS: The negative impact of chromium was observed in relation to bone tissue. All doses significantly decreased total skeleton density and mineral content, and also had impact upon the isolated femora and vertebral column. Trabecular volumetric bone mineral density and trabecular bone mineral content measured by pQCT in distal femur metaphysis were significantly lower in the experimental groups than in the control. Higher doses of chromium also significantly decreased values of ultimate strength and Young modulus in the investigated femora. CONCLUSIONS: The results of the experiment demonstrate that chromium sulphate is dose dependent, and exerts a disadvantageous effect on the skeleton, as it decreases bone density and resistance.

Effects of long-term oral administration of methimazole on femur and tibia properties in male Wistar rats.

Physiological concentrations of thyroid hormones are crucial for skeletal growth and development, physiological bone turnover and bone homeostasis maintenance. Methimazole (1-methyl-2-mercaptoimidazole) is an antithyroid drug used for the treatment of the hyperthyroidism in humans and animals. The aim of the study was to determine effects of long-term oral methimazole treatment in male Wistar rats on biochemical bone metabolism markers, as well as morphological, geometric, densitometric and mechanical properties of femur and tibia. Experimental rats were subjected to 90-day-long oral treatment with 0.05% water solution of methimazole and were kept under identical environmental conditions and received the same diet ad libitum as the control group. Serum concentration of osteocalcin (OC) and C-terminal telopeptides of type I collagen (CTX-I) was determined. Femur and tibia were evaluated using quantitative computed tomography (QCT), peripheral QCT (pQCT) and three-point bending test. Final body weight of the experimental group was significantly decreased by 30% (P=0.01). Methimazole treatment significantly decreased serum OC concentration by 21% (P=0.02) and increased CTX-I concentration by 17% (P=0.06). Methimazole decreased morphological, geometric and densitometric parameters of femur and tibia in rats. Mechanical evaluation of bones has shown significantly decreased maximum elastic strength and ultimate strength of femur in rats treated with methimazole by 36% and 40% when compared to the control group (P<0.05). In conclusion, this study has shown that long-term treatment with methimazole inhibits bone formation and accelerates bone resorption processes. The observed negative effects of methimazole treatment on body weight gain and skeletal properties may be considered as additional possible side effects in living organisms to those reported in the previous studies. It may be suggested that long-term antithyroid treatment should be combined with prevention of the negative effects of methimazole on bone tissue and whole body metabolism.

Alteration in bone geometric and mechanical properties, histomorphometrical parameters of trabecular bone, articular cartilage, and growth plate in adolescent rats after chronic co-exposure to cadmium and lead in the case of supplementation with green, black, red and white tea.

Adolescent male Wistar rats were used to check whether regular consumption of black, red, white, or green tea would have a protective effect on femur development during 12-week exposure to Cd and Pb (7mg Cd and 50mg Pb in 1kg of the diet). The animals were randomly divided (n=12) into a positive control (without Cd, Pb and teas), a negative control group (Cd and Pb), and groups supplemented additionally with green (GT), black (BT), red (RT), and white tea (WT). Heavy metals reduced the geometric and densitometric parameters and the total thickness of articular cartilage irrespective of tea administration and influenced mechanical endurance, growth plate thickness, and trabecular histomorphometry depending on the tea type. It is difficult to indicate which tea has the best protective effects on bone and hyaline cartilage against heavy metal action.