Shaikh Masood Ahmed, Naeem Zahid, Alshahat Abd Alrahman, Shaikh Farooque Ahmed, Arif Shahan
Professor, Department of Anatomy and Histology, College of Medicine, Qassim University, Saudi Arabia.
Int J Health Sci (Qassim). 2013 Jan;7(1):31-43. doi: 10.12816/0006018.
This study is intended to examine the effect of hypothyroidism and thyroxin replacement on axial and appendicular skeletal growth, growth plate thickness and to observe associated microscopic changes within the growth plates.
Experimental albino rats were developed with carbimazole and carbimazole plus thyroxin. Animals were administered with these drugs throughout pregnancy (prenatally) and for a period of six weeks, postnatally. At the end of the experiment the animals were sacrificed, measured and processed to demonstrate the bony and cartilaginous parts. Ulna and tibia of both sides were removed and processed for light microscopy and growth plate measurement.
At the end of the experiment, reduction in the crown rump length was observed in the carbimazole treated animals. It was 8.77%, 13.26% and 7.25% in the prenatal, two weeks and six weeks age group animals respectively. In carbimazole plus thyroxin treated animals, this reduction was 3.22%, 2.94% and 3.42%, when compared to their age matched controls. Reduction in the thickness of the Epiphyseal growth plate (EGP) was 16.89% and 12.80% in the ulna of the two and six weeks age group and 18.06 % and 15.65% in the tibia of the these animals respectively. The carbimazole plus thyroxin treated animals showed an increase in the thickness of EGP as compared to their age-matched controls though the crown rump length of these animals was less than the controls. Prenatally treated hypothyroid rats showed disrupted growth plates without any well-formed microscopic zones.
The results of this study showed that the pre and postnatally, carbimazole induced hypothyroidism and its replacement therapy affected the axial and appendicular skeletal growth. Proximal limb bones of the prenatally induced hypothyroid animals showed the greatest skeletal change in this study.
本研究旨在探讨甲状腺功能减退及甲状腺素替代治疗对轴骨和附肢骨骼生长、生长板厚度的影响，并观察生长板内相关的微观变化。
用卡比马唑以及卡比马唑加甲状腺素培育实验性白化大鼠。在整个孕期（产前）及产后六周给动物施用这些药物。实验结束时，处死动物，进行测量并处理以显示骨骼和软骨部分。取出双侧尺骨和胫骨，进行光镜检查和生长板测量。
实验结束时，在接受卡比马唑治疗的动物中观察到顶臀长度减少。产前、两周龄和六周龄组动物分别减少了8.77%、13.26%和7.25%。与年龄匹配的对照组相比，在接受卡比马唑加甲状腺素治疗的动物中，这种减少分别为3.22%、2.94%和3.42%。在两周龄和六周龄组动物的尺骨中，骨骺生长板（EGP）厚度分别减少了16.89%和12.80%，在这些动物的胫骨中分别减少了18.06%和15.65%。与年龄匹配的对照组相比，接受卡比马唑加甲状腺素治疗的动物的EGP厚度增加，尽管这些动物的顶臀长度小于对照组。产前接受治疗的甲状腺功能减退大鼠的生长板出现紊乱，没有任何形态良好的微观区域。
本研究结果表明，产前和产后，卡比马唑诱导的甲状腺功能减退及其替代疗法影响了轴骨和附肢骨骼的生长。在本研究中，产前诱导甲状腺功能减退动物的近端肢体骨骼显示出最大的骨骼变化。
