No abstract

The aim of the research is to study the histological structure of proximal metaphysial cartilage of the humerus in adult rats after 60 days of tartrazine administration (750 mg/kg and 1500 mg/kg body weight). Materials and Methods. The study was carried out on 90 white male rats, divided into 3 groups. In Group 1 (control), animals daily intragastrically received 1ml of 0.9 % isotonic sodium chloride solution for 60 days. Rats of Groups 2 and Group 3 received intragastrically 1ml of tartrazine solution (750 mg/kg and 1500 mg/kg body weight respectively) for 60 days. The readaptation period after the last tartrazine administration was 3, 10, 15, 24, or 45 days. The area of the proximal humerus metaphysis underwent treatment according to the standard histological protocol. The obtained sections were stained with hematoxylin-eosin and subjected to a subsequent histomorphometric study. Results. On the 3rd day of the readaptation period, the total width of the proximal metaphysial cartilage of the humerus in animals of Group 2, was by 8.59 % less than the values of the control group; the width of the indifferent, proliferating and definitive cartilage was by 6.11 %, 8.85 % and 7.15 % less; the width of the destruction zone was by 11.55 % less; and the width of the osteogenesis zone was by 9.92 % less. The content of primary spongiosis in the osteogenesis zone and the number of cells on the trabeculae surface were lower than the values of Group 1 by 8.45 % and 8.42 % respectively. During the readaptation period, the authors observed similar dynamics of changes in the histomorphometric parameters of the metaphysical cartilage of the humerus with levelling by the 45th day of the experiment. In rats of Group 3, during the entire readaptation period, the histomorphometric parameters changed more significantly and their recovery to control values was slower than in animals of Group 2. Conclusion. 60-day tartrazine administration to adult rats is accompanied by inhibition of the bone formation function of the proximal metaphysial cartilage of the humerus. It is confirmed by a decrease in the width of all its zones and components of the osteogenesis zone. More pronounced in amplitude and duration changes in the parameters studied were recorded in animals treated with tartrazine, 1500 mg/kg body weight. Keywords: humerus, metaphysial cartilage, tartrazine, histomorphometry. Цель исследования. Установить, оказывает ли влияние 60-дневное введение тартразина в дозах 750 и 1500 мг/кг массы тела на гистологическое строение проксимального метафизарного хряща плечевой кости у половозрелых крыс. Материалы и методы. Исследование проведено на 90 белых крысах-самцах, распределенных на 3 группы: 1-я – контрольная, в которой животные ежедневно в течение 60 дней получали физиологический раствор через желудочный зонд; 2-ю и 3-ю группы составили крысы, которые на протяжении 60 дней получали внутрижелудочно 1 мл раствора тартразина в дозах 750 и 1500 мг/кг массы тела соответственно. Сроки периода реадаптации после окончания введения тартразина составляли 3, 10, 15, 24, 45 сут. Проксимальный метафиз плечевой кости подвергался обработке по стандартному гистологическому протоколу. Полученные срезы окрашивались гематоксилин-эозином и подвергались последующему гистоморфометрическому исследованию. Результаты. У животных 2-й группы на 3-й день периода реадаптации общая ширина проксимального метафизарного хряща плечевой кости была меньше значений контрольной группы на 8,59 %, ширина зон индифферентного, пролиферирующего и дефинитивного хряща – на 6,11, 8,85 и 7,15 % меньше, ширина зоны деструкции – на 11,55 %, а ширина зоны остеогенеза – на 9,92 %. Содержание первичной спонгиозы в зоне остеогенеза и количество клеток на поверхности трабекул были меньше значений контрольной группы на 8,45 и 8,42 %. В ходе периода реадаптации сходная динамика изменений гистоморфометрических параметров метафизарного хряща плечевой кости сохранялась с тенденцией к сглаживанию к 45-м сут эксперимента. У крыс 3-й группы в ходе всего периода реадаптации изучаемые параметры изменялись более значимо и их восстановление до контрольных величин происходило медленнее, чем во 2-й группе. Выводы. 60-дневное введение тартразина половозрелым крысам сопровождается угнетением костеобразовательной функции проксимального метафизарного хряща плечевой кости, что подтверждается снижением ширины всех его зон и объемных компонентов зоны остеогенеза. Более выраженные по амплитуде и длительности изменения изучаемых параметров зафиксированы у животных, получавших тартразин в дозе 1500 мг/кг массы тела. Ключевые слова: плечевая кость, метафизарный хрящ, тартразин, гистоморфометрия.

Currently, sodium benzoate is widely used in the food industry, cosmetology and medicine. The literature provides information about the effect of its introduction on the growth and shaping of bones, the parameters of the crystal lattice of the regenerate formed therein. However, information about the effect of this food additive on the phase composition of the bone regenerate being formed and the degree of this influence is practically absent, which was the purpose of the study. The experiment was conducted on 210 white male rats, divided into 6 groups: 1st - control animals, 2nd and 3rd - rats, daily receiving intragastrically 1 ml of sodium benzoate 500 and 1000 mg/kg/day, respectively for 60 days. The 4th group - rats being inflicted a defect in both tibial bones, and the 5th and 6th - rats being inflicted a defect after the end of the 60-day injection of sodium benzoate. The timing of the experiment after the introduction of sodium benzoate was 3, 10, 15, 24 and 45 days. The area of the forming regenerate of tibial bones was investigated by X-ray diffraction analysis: the percentage content in the mineral of the regenerate of whitlockite, hydroxylapatite and calcite was calculated by the method of internal control. The impact of the introduction of sodium benzoate and the application of the defect on the above indicators was evaluated by two-factor analysis of variance. The results of the study showed that 60-day administration of sodium benzoate leads to an increase in the amorphism of the biomineral of the forming regenerate of tibial bones, the severity and recovery rate of which depends on its administered dose. Thus, the group being inflicted the defect of the tibial bones after the completion of the 60-day administration of sodium benzoate at a dose of 500 mg/kg/day had greater calcite content on day 10 to 45 by 17.88%, 12.88% and 6.63%, and whitlockite - on day 3, 24 and 45 by 14.30%, 4.52% and 6.20%, and hydroxylapatite - less on day 15 to 45 by 3.11%, 3.31% and 2.14%, compared with the defect-inflicted group without the introduction of sodium benzoate. An increase in the administered dose of sodium benzoate up to 1000 mg/kg/day led to aggravation of the identified deviations: the whitlockite content on day 3, 24, and 45 was higher by 16.15%, 6.21% and 9.54%, and the hydroxylapatite content on day 15 to 45 was lower by 3.98%, 4.16% and 3.34%. The conducted two-factor analysis of variance showed that the introduction of sodium benzoate had a significant effect on the change in the content of calcite, whitlockite and hydroxylapatite in the regenerate, the strength and duration of which depends on its administered dose. The maximum power of influence was registered for the increased content of calcite and the decreased content of hydroxylapatite in the mineral of the regenerate on day 45 of the experiment, and for the increased content of whitlockite - on day 3. When a defect was inflicted, the power of influence was maximal for the increased content of calcite and decreased content of hydroxylapatite on day 10, and the increased content of whitlockite - on day 15. In this case, a reverse dose-dependent effect was observed in all periods of the experiment.