Effects Of Vitamin A Deficiency On Skeletal Development In Three Weeks Old Rats

Objective To study the effect of vitamin A deficiency on skeletal development in three weeks old rats.Methods:24 male Wistar rats of 21-23days after birth were divided into 3 groups randomly.The rats were fed with vitamin A (VA).Group 1 was fed with vitamin A 6500IU/kg diets as control(CN) , Group 2 was fed with VA 400IU/kg diets as moderate vitamin A deficiency(MVAD),Group 3 was fed with VA 0IU/kg diets as serious vitamin A deficiency(SVAD).All groups of young rats'body weight,body length and tail length were measured every 7 days.After 70 days of feeding , the length of femur,VA,GH,IGF,FT3,FT4 and TSH levels in serum were detected, and the histology of femur growth plate was also observed.Results: (1)The serum vitamin A of male rats fed with VA 6500IU/kg diets was (1.21±0.06)μmol/ L,Those fed with VA 400IU/kg diets was (0.98±0.09)μmol/ L, respectively. Those fed with VA 0IU/kg diets was (0.23±0.05)μmol/ L.Compared to the CN and MVAD groups, the VA levels of SVAD in serum were lower (P<0.01). Compared to the CN groups,the VA levels of MVAD in serum were lower (P<0.01).(2) Compared to the CN and MVAD groups,The body weights,lengths and tail lengths of the SVAD groups were decreased(P<0.01).Comparing the MVAD and CN groups, there were no significant differences in the body weights,lengths and the tail lengths(P>0.05).(3) Compared to the CN and MVAD groups,the femur lengths of the SVAD groups were significantly lower than those of the CN groups(P<0.01).Comparing the MVAD and CN groups, there were no significant differences in the femur lengths(P>0.05).(4) Compared to the CN and MVAD groups ,serum GH and IGF were lower than the SVAD groups(P<0.05). Comparing the MVAD and CN groups, there were no significant differences in serum GH and IGF (P>0.05). (5)Compared to the CN and MVAD groups,serum FT3 and TSH were higher than the SVAD groups(P<0.05). Comparing the MVAD and CN groups, there were no significant differences in serum FT3 and TSH (P>0.05).(5) The histology of growth plate was very different, and the height of the rat proximal femur growth plate was reduced by inhibiting proliferative and hypertrophic zone.Conclusions:(1) SVAD can affect skeletal development of young rats by inhibiting growth plate.(2) SVAD can affect skeletal development in rats and the skeletal development defects may be related with the decreased expression of GH and IGF in serum.(3) SVAD can affect skeletal development in rats and the skeletal development defects may be related with the increased expression of FT3 and TSH in serum...