M. Hirota et al., CHANGES IN NERVE GROWTH-FACTOR CONTENT OF THE SUBMAXILLARY-GLAND IN THE GENETICALLY DYSTROPHIC (MDX) MOUSE, Journal of the neurological sciences, 121(2), 1994, pp. 176-182
We evaluated the nerve growth factor (NGF) contents in the submaxillar
y gland of the mdx mouse, a model for Duchenne muscular dystrophy (DMD
), and found that the NGF and NGF mRNA contents in this organ, where e
xtraordinarily high amounts of NGF are synthesized and stored independ
ently of development or maintenance of the nervous system, were marked
ly elevated in the male mdx mouse at 8 and 11 weeks of age. However, t
he NGF content of this organ in 4-week-old male mdx mice was lower tha
n that of control mice although statistical significance of difference
was not observed. In the mdx female mouse, the submaxillary NGF conte
nt was significantly lower than that of the normal mouse at 4 weeks of
age, but was similar to that of the normal at 8 and 11 weeks of age.
The amounts of epidermal growth factor (EGF), another protein that is
known to be sexually and developmentally regulated in the mouse submax
illary gland like NGF, was found to be also significantly increased in
this organ of the male mdx mouse at 8 and 11 weeks of age, and to be
significantly decreased in that of the female mdx mouse at 4 weeks of
age. The parallel changes in NGF and EGF contents during development o
f the submaxillary gland suggest that the mdx mouse suffers from some
abnormality in the development of this organ. The concentration of ser
um thyroxine (T4) was significantly reduced in afflicted males and fem
ales during the period examined (from 4 to 11 weeks after birth); and
that of serum testosterone was significantly reduced in 4-week-old mal
e mdx mice, but no significant differences were observed in 8- or 11-w
eek-old afflicted males or 4- to 11-week-old afflicted females. These
results suggest that the abnormality in the development of the submaxi
llary gland in the mdx mouse is due to the abnormalities of these horm
one levels.