The Immunohistochemical and Morphometric Study of the Effect of Nerve Growth Factor on Spinal Ganglia in Streptozotocin-Induced Diabetic Rats

Abstract

Recently diabetic neuropathy has been postulated to occur from reduced availability of

neurotrophic factor. This experiment was performed to identify the effect of nerve

growth factor on dorsal root ganglia(DRG) in the streptozotocin-induced diabetic rat

using morphometry and immunohistochemistry.

The results obtained are as follows :

1. Unlike in the diabetic group where the type A and B cells were significantly

decreased in their total numbers and sizes, these cells were normal in NGF-administered

diabetic group.

2. Numbers of cells immunoreactive with SP and CGRP were also significantly

decreased in the diabetic group. However, the NGF-administered diabetic group did not

show any reduction in the number of these cells.

3. Mean sizes of cells immunoreactive with SP and CGRP cells were reduced in the

diabetic group by 18.1% and 26.6% respectively(P< 0.01). On the other hand, in

NGF-administered diabetic group, mean sizes of SP-immunoreactive cells were increased

(10.5%) which was not statiatically significant, and those of CGRP-immunoreactive cells

were decreased (18%) compared to the control group (P< 0.01).

4. In the diabetic group, many of nerve cell bodies showed some degenerative

characteristics including neuron-satellite cell interface of irregular shape, the presence of

a number of vacuoles and dense bodies, and nucleus of irregular contour. However,

NGF-administered diabetic group exhibited neuron-satellite cell interface of regular form,

many neurofilaments and neurotubules, and normal htracellular organelles.

These results suggest that administration of NGF protects spinal ganglion cells from

morphometric and morphological changes which are associated with a streptozotocin

-induced diabetic neuropathy.