Differential expression of calbindin D28k, calretinin and parvalbumin in the cerebellum of pups of ethanol-treated female rats.

Three calcium-binding proteins (CaBPs), calbindin D28k, calretinin and parvalbumin, were immunohistochemically examined in the cerebellum of ten-day-old rat pups of ethanol-treated dams. Dams were treated with ethanol during pregnancy and/or lactation. In the cerebellar cortex of the pups from control groups, Purkinje cells with their processes and Golgi cells were positive for calbindin D28k, whereas interneurons (Lugaro, Golgi and unipolar brush cells) and sometimes Purkinje cells were positive for calretinin. Parvalbumin immunoreactivity was observed in Golgi and basket cells, stellate cells and in some Purkinje cells. The number of positive cells and staining intensity for calbindin D28k and parvalbumin decreased in all experimental groups, whereas the immunoreaction for calretinin was visible only in interneurons and was more intense in experimental than in control groups. Calbindin D28k immunoreactivity in experimental groups was detected in some Purkinje cells and rarely in Golgi cells. The localization of very intense calretinin expression was visible mainly in unipolar brush cells. A parvalbumin-positive reaction was detected in single Purkinje cells and sometimes in basket cells. The results of the present study showed that immunoreactivity of the three calcium-binding proteins was found in the cells of the cerebellum of the ten-day-old pups from the control groups. In experimental groups of females treated with ethanol during pregnancy and/or lactation, we observed the most significant decrease in both the intensity and the number of immunoreactions of calbindin D28k and parvalbumin, but the intensity of the immunoreaction for calretinin was increased for interneurons. Ischaemic damage to Purkinje cells and loss of interneurons and Purkinje cells were also noted in these groups. A possible correlation between the duration of ethanol intoxication, expression of calcium-binding proteins and pathological changes of cells in the cerebellar cortex of the pups of ethanol-treated dams is discussed.