Subacute exposure to amygdalin influences compact bone remodeling of rabbits.

Amygdalin is most commonly occurring cyanogenic glycoside. It is found in seeds of many plant species. Our study was aimed to reveal whether pure intramuscularly injected amygdalin or apricot seeds peroral exposure cause changes in bone microstructure of rabbits. Twenty clinically healthy 5 months-old male rabbits were segregated into five groups. Animals from groups A1 and A2 were intramuscularly injected with amygdalin at doses of 0.6 and 3 mg/kg b.w. daily for 28 days. The groups S1 and S2 received commercial feed for rabbits mixed with crushed bitter apricot seeds at doses of 60 and 300 mg/kg b.w. during 28 days. The control (C) group did not receive any amygdalin. Intramuscular and peroral amygdalin administration did not affect total body weight, femoral length and femoral weight of rabbits. Similarly, microcomputed tomography (3D analysis) has shown that amygdalin had insignificant effect on relative bone volume, bone mineral density, cortical bone thickness, bone surface, trabecular thickness, trabecular number, trabecular separation. However, histological (2D analysis) revealed evident changes in compact bone microstructure of amygdalin-exposed rabbits consistent with a different vascularization and changed biomechanical properties. We can conclude that subacute exposure to amygdalin (both intramuscular and peroral) at the doses used in our study influenced compact bone remodeling.

Bone microstructure of mice after prolonged taurine treatment.

Taurine, a sulphur - containing amino acid, has been termed a functional nutrient. Its synthetic form is a common ingredient in supplements and energy drinks. There is no information concerning taurine impact on bone microstructure after prolonged supplemental use. Also, differences in bone parameters of mice following taurine exposure are unknown. In this study, a detailed microstructure of compact and trabecular bone tissues of mice subchronically exposed to taurine was determined. Animals (n=12) were segregated into three groups: E1 group - mice received 20 mg/kg b.w. of taurine per day during 8 weeks; E2 group - mice were fed by taurine at a dose of 40 mg/kg b.w. for 8 weeks and a control (C) group. Decreased density of secondary osteons, increased sizes of primary osteon's vascular canals (P<0.05) were observed in taurine - treated animals. Cortical bone thickness, trabecular thickness were decreased (P<0.05) in E1 group, and relative volume of trabecular bone was lower (P<0.05) in E2 group as compared to C group. According to our results, prolonged taurine exposure at the doses used in this study can negatively affect both compact and trabecular bone tissues microstructure.

Subacute exposure to alcohol in relation to bone microstructure of mice.

Our study aimed to investigate subacute exposure to alcohol in relation to bone microstructure of mice. Animals from experimental (E) group drank a solution composed of 15 % ethanol and water for 14 days (one remodeling cycle), while those from control (C) group drank only water. In the compact bone of E group, decreased bone formation and increased porosity were observed which corresponds with lower levels of serum alkaline phosphatase and glutathione. Alcohol significantly increased sizes of primary osteon's vascular canals and decreased those of secondary osteons, Haversian canals. Relative bone volume, bone mineral density (BMD), relative bone volume without marrow cavity were also lower in E group. On the contrary, trabecular bone microstructure did not differ significantly between E and C groups. Liver function test showed higher levels of alanine aminotransferase, aspartate aminotransferase in alcohol-fed mice. Serum calcium, phosphate were significantly lower in E group. According to our study, only changes in compact bone microstructure of mice following one remodeling cycle were observed due to both direct and indirect effects of alcohol.

Acrylamide-induced changes in femoral bone microstructure of mice.

Acrylamide (AA) is one of the most common toxins in foods. Its effect on bone microstructure has not been investigated. The aim of our study was to analyze the impact of acute exposure to AA on femoral bone microstructure in mice. Adult animals were treated perorally with 2 doses of AA (E1 group, 1 mg/kg b.w.) in a 24-h period and with 3 doses of AA (E2 group, 1 mg/kg b.w.) in a 48-h period. Mice exposed to AA had smaller sizes of primary osteon's vascular canals. Secondary osteons were significantly smaller in mice from E2 group; however their increased number (from 38 % to 77 %) was identified in both E1 and E2 groups. In these groups, a higher number of resorption lacunae (from 100 % to 122 %) was also found. The values for bone volume, trabecular number were increased and that for trabecular separation was decreased in mice administered AA. Significantly higher value of bone surface was observed in mice from E1 group whereas trabecular thickness was increased in E2 group. The effect of AA on microstructure of compact and trabecular bone tissues is different. In our study, one dose of AA was used and acute effects of AA were investigated. Therefore, further studies are needed to study mechanisms by which AA acts on bone.