Vitamin A deficiency does not influence longitudinal growth in mice.
OBJECTIVE
Growth hormone (GH) stimulates longitudinal growth, directly and indirectly, through the mediation of circulating and locally produced insulin-like growth factor 1 (IGF-1). The exact role of individual vitamins in modulating GH secretion or action, and somatic growth in general, is still not completely understood. It has been suggested that vitamin A (VA) and its physiologic active metabolite retinoic acid influence longitudinal growth by promoting the differentiation of pituitary cells toward GH-secreting cells and by stimulating secretion of GH. Accordingly, epidemiologic studies have shown that short children have lower VA intake than do children with normal stature.


METHODS
To determine whether VA deficiency causes impairment of GH secretion, we have investigated the effect of a severely VA-deficient diet on growth in mice. Ten male mice born from mothers fed with VA-deficient diet since conception were maintained on a VA-deficient diet until the end of week 8 of life. Ten male mice born from mothers fed with a VA-sufficient diet and receiving a normal diet after weaning served as the control group. At the end of the study, we measured animals' weight and length, body composition, tibia and femur lengths, liver retinol and retinyl esters storages, serum IGF-1, serum thyroxine, serum GH, and pituitary GH mRNA levels.


RESULTS
Despite evidence of significant VA deficiency, we observed no effect on longitudinal growth or changes in pituitary GH mRNA, serum thyroxine, serum GH, or serum IGF-1 levels.


CONCLUSIONS
VA deficiency does not negatively affect longitudinal growth and pituitary GH content and action in mice.
Sagazio
Alessia
A
Department of Medicine, Division of Endocrinology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Piantedosi
Roseann
R
Alba
Maria
M
Blaner
William S
WS
Salvatori
Roberto
R
D000375:Aging / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D006128:Growth / Q000502:physiology*; D013006:Growth Hormone / Q000172:deficiency / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism; D014801:Vitamin A / Q000097:blood; D014802:Vitamin A Deficiency / Q000378:metabolism* / Q000503:physiopathology
D012333:RNA, Messenger; D014801:Vitamin A; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone