Endocrine Abstracts

Numerous hormonal and metabolic disorders caused by thyrotoxicosis lead to serious complications, so early diagnosis and adequate treatment becomes very important in warning of functional and organic changes in several organ systems, particularly in the structure of bone tissue.

The aim was study of the effectiveness of calcium and alendronate for prevention and treatment of BMD losing in experimental models of thyreotoxicosis.

Material and methods: Used 47 female Wistar rats 8-10 month age with body mass 207.81±3.27 g. Depending on the medication, animals are divided into five groups: isotonic solution of sodium chloride (control), L-thyroxine, L-thyroxine and calcium, L-thyroxine, calcium and alendronate, L-thyroxine for two weeks before and during the experiment, calcium and alendronate. L-thyroxine (25 mcg/100 g) and solution of sodium chloride injected sucutaneously daily, calcium (2.1 mg/100 g) daily and alendronate (1.75 mg/100 g) once at week entered through the esophageal probe. BMD of whole skeleton, spine and hind limbs measured at the beginning and after five weeks of experiment using a densitometer Prodigy (GE Medical systems). Data were analyzed using ANOVA and Student’s t-test to examine differences among the groups.

Results: In the control group of animals BMD increases in all parts of the skeleton (1.25±3.2% to 15.76±1,05%). The greatest loss of BMD was observed in L-thyroxine medicated rats (−5.95±2.36 to −14.13±1.46%). In the group of animals with thyrotoxicosis that received medication calcium, observed retardation of sceleton growth and a moderate loss of BMD from (0.49±2.13% to −5,11±2.52%), that has significant differences with group with thyreotoxicosis at hind limbs and whole sceleton. In groups of animals with thyrotoxicosis and calcium and alendronate medication observed increasing BMD that has not significant differences with control group.

Conclusion: In the experiment, exogenous hyperthyroidism resulted in reliable loss of BMD, mainly peripheral skeleton (by 14.13% at the hind limbs and 5.95% at the spine). Use of calcium during exogenous hyperthyroidism in female rats significantly reduces bone loss. The combination of calcium and alendronate prevents losing BMD, regardless of the duration of hyperthyroidism.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.