Endocrine Abstracts

The aim: To study age-dependent changes of bone mineral density of females and males rats in remote terms after hyperthyroidism abolition.

Research Object: Research is conducted on 180 white females and males rats of ‘Wistar’ breed. Animals were arranged in the 18 groups: six controls groups (CG) of pre-pubertal, reproductive and old males and females; six groups of rats with the experimental model hyperthyroidism (HTG); six groups of rats 30 days after stopping L-thyroxine injections (STI).

Research methods: Bone mineral density (BMD) was measured using dual energy X-ray densitometry (DEXA) and ‘Experimental animals’ software.

Research results: Through 30 days after STI, was revealed decline the Δ BMD of pubertal females rats at 4.3 time (with 44.73±5.41% in HTG to 10.47±6.32%, Student’s t-criterion t=−4.03, P<0.0001) and of males at 5,7 time (with 22.83±2.84% in HTG to 44.73±5.41%, Student’s t-criterion =4.49, P<0.0001). Only reproductive females cans recover a total D BMD to the level of age control group (with −10.04±2.32% in HTG to 22.63±6.87%, Student’s t-criterion =5.68, P<0.0001.). The reproductive males showed only 70 percent recover of DBMD (with −4.31±2.63% in HTG to 6.69±3.04%, Student’s t-criterion=−2.64, P < 0.015). In old males rats D BMD was declined (with 6.91±1.49% in HTG to −3.75±1.93%, Student’s t-criterion =4.30, P < 0.0001). For females a decline of DBMD (%) was not statistically considerable.

Conclusions: The study age-dependent and gender characteristics of changes in bone mineral density of rats 30 days after hyperthyroidism abolition the exposed, that BMD is restored only at reproductive females of rats and a partial (70%) at reproductive males. The decline of BMD is exposed in other investigational groups.

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.