Aim of the study is to investigate strength features of mandible and humerus in adult rats after 2-month administration of sodium benzoate. Materials and methods. The study involved 105 adult male rats with initial body weight of 200-210 grams. The animals were separated into three groups as follows: the first group comprised the control animals that received 1 ml of 0. 9% solution of sodium chloride daily throughout 60 days of observation period, the second and the third groups comprised animals that received per os 1 ml of sodium benzoate solution (Eastman Chemical B. V. packed by “Farmatsevticheskaya fabrika” by order of JSC “Eximed”) in dosage of 500 and 1000 mg per kg of body weight respectively (groups B1 and B2 respectively). Readaptation terms were 3, 10, 15, 24 and 45 days. Upon expiration of each interim the respective animals were withdrawn from the experiment by means of decapitation under general anesthesia. Strength tests were performed using universal loading test device R-0. 5 at bending with load rate of 0. 25 mm/ min. The device employed three point loading model. The data were used for calculations of specific bending de-flection, braking point, elasticity modulus and minimum destruction work. Results and discussion. Daily per os administration of sodium benzoate in dosage of 500 mg per kg of body weight resulted in bone strength decrease. By the 3rd day after sodium benzoate discontinue, in mandible, the spe-cific bending deflection values were higher than those of the controls by 6. 62% and fracture point, breaking point, elasticity modulus and destruction work of the same mandible were lower by 6. 13%, 9. 30%, 7. 47% and 8. 59% respectively. In humerus, specific bending deflection values were higher than those of the controls by 7. 38% and fracture point, breaking point, elasticity modulus and destruction work of the same mandible were lower by 7. 94%, 6. 39%, 5. 79% and 6. 85% respectively. Readaptation period in B1 group featured gradual restoration of strength of the bones and significant changes were observed mostly up to the 15th day of observation period. In the case of administration of 100 mg per kg of body weight, strength of bones was affected as well but to a greater extent as compared to B1 group. Upon sodium benzoate discontinue in B2 group by the 3rd day, the specific bending deflection values of man-dible were higher than those of the controls by 7. 92% and fracture point, breaking point, elasticity modulus and destruction work of the same mandible were lower by 7. 74%, 11. 41%, 11. 57% and 10. 68% respectively. In humerus, specific bending deflection values were higher than those of the controls by 8. 80% and fracture point, breaking point, elasticity modulus and destruction work of the same mandible were lower by 9. 64%, 9. 43%, 9. 59% and 9. 15% respectively. Readaptation period up to the 15th day featured similar changes of strength, which gradually returned to baseline values later on. Conclusions. Daily per os 60-day administration of sodium benzoate affects strength of mandible and humerus depending on dosage. Dosage of 1000 mg per kg of body weight has more expressed effects on strength features of the bones than 500 mg of the same substance. In readaptation period after sodium benzoate discontinue, sig-nificant changes in animals that received 500 mg of medicine were observed up to the 15th day of observation while 1000 mg of substance affected bone strength even up to the 45th day of observation.
sodium benzoate, mandible, humeral bone, strength
«Bulletin of problems biology and medicine» Issue 2 part 1 (107), 2014 year, 217-220 pages, index UDK 519. 443:[613. 648. 4+613. 37
