Quantitative evaluation in vivo of the degree of differentiation of hindlimb cartilage in a rat clubfoot model.
The Limb Morphogenetic Differentiation Scoring system introduced by Neubert and Barrach in 1977 has been used in drug testing as a measure of the degree of cartilage growth inhibition especially for forelimb in vitro. There is no scoring system to quantify the degree of hindlimb bud cartilage differentiation in vivo. A total of 60 female Sprague-Dawley rats weighing 220-250 g were assigned at random to six control groups and six experimental groups on day 0 of pregnancy. The experimental groups were treated with all-trans-retinoic acid (ATRA). A new limb morphogenetic differentiation scoring system was developed and used to quantify the degree of development of the hindlimb buds from the fetuses at embryonic days E13 to E18. The differentiation of cartilages assessed by the new scoring system showed a statistically significant difference between the experimental group and the control group from E13 to E18 (T-test, p < 0.05). Cartilage growth (the proximodistal length) in the control group increased gradually from E14, reaching its peak at E17, but in the experimental group the growth at E13, E16, E17, and E18 was significantly shorter (p < 0.05). In conclusion, the new limb morphogenetic differentiation scoring system described here can be used to quantify the degree of inhibition of the hindlimb bud development by teratogenic drugs or materials, and morphogenetic differentiation in vivo.
Zhong
Yong-Sheng
YS
Department of Orthopaedics, the 1st Affiliated Hospital, Medical College of Shantou University, Shantou, Guangdong, PR China.
Zheng
Chuangyi
C
Jia
Yanli
Y
Xu
Geng-Tian
GT
Liu
Zhao-Yong
ZY
Chen
Bin
B
Du
Shi-Xin
SX
D000818:Animals; D002356:Cartilage / Q000196:embryology*; D003025:Clubfoot / Q000196:embryology*; D004195:Disease Models, Animal; D005260:Female; D006614:Hindlimb / Q000196:embryology*; D018878:Limb Buds / Q000196:embryology; D009024:Morphogenesis; D051381:Rats; D017207:Rats, Sprague-Dawley