Y. Omura et al., IMMUNOCYTOCHEMICAL LOCALIZATION OF TAURINE IN THE PINEAL ORGAN AND RETINA OF AN ANADROMOUS FISH, PLECOGLOSSUS-ALTIVELIS, Archives of histology and cytology, 60(2), 1997, pp. 153-162
Light and electron microscopic immuno-localization of taurine, a sulfu
r-containing free amino acid, was investigated in the photoneuroendocr
ine pineal organ and the retinal photoreceptor and pigment epithelial
layer of the ayu Plecoglossus altivelis, an anadromous fish, Intense i
mmunostaining was found in the outer segments of pineal photoreceptors
and retinal cone-like cells. Moderate but definite immunostaining was
found in the cytoplasmic processes of pineal supporting cells, the ou
ter segments of retinal rod-like cells, and the apical processes of pi
gment epithelial cells. Although the electron microscopic immunogold l
abeling was not completely coincident with the results of light micros
copic immunostaining, concentrated immunogold particles appeared in th
e inner segments of photoreceptor cells, the cytoplasmic processes of
pineal supporting cells, and the apical processes of pigment epithelia
l cells. These light and electron microscopic findings in taurine immu
nolocalization mere discussed in relation to the functions of taurine
known mainly from retinal physiology. It was suggested that the abunda
nt taurine localization may be involved st least in the protection of
photoreceptor outer segments against harmful factors, and in the trans
portation of nutrients and metabolites, The immunostaining for taurine
is useful for the discrimination of different types of photoreceptor
cells in the pineal organ and retina of fish.