Immunohistochemical studies on supporting cells in the adrenal medulla and pineal gland of adult rat, especially on S-100 protein, glial fibrillary acidic protein and vimentin.

In the adrenal medulla and pineal gland, the morphological and chemical nature of supporting cells were examined immunohistochemically. In the adrenal medulla, supporting cells in noradrenaline (NA)-cell regions showed similar and intense immunoreactivities to the three glial marker proteins, S-100 protein, glial fibrillary acidic protein (GFAP) and vimentin, forming a network, while those in adrenaline (A)-cell regions were less numerous and their immunoreactivity was positive to S-100 protein but negative to GFAP and, at least in part, negative to vimentin. In the pineal gland, supporting cells in the stalk and the proximal region of the 1x>dy portion formed a network and showed immunoreactivities to the three antibodies, while those in the distal region of the body portion were less numerous and their immunoreactivity was positive to S-l00 protein and vimentin, but negative to GFAP. Thus, the distribution pattern and chemical nature of supporting cells showed regional differences in both glands. There were several similarities in supporting cells between those in NA-cell regions of the adrenal medulla and in the stalk and the proximal region of the body portion of the pineal gland, and also between in A-cell regions of the adrenal medulla and in the distal region of the body portion of the pineal gland, respectively. The biological and functional significances of these results are discussed.