Calbindin D28k and calretinin in oxytocin and vasopressin neurons of the rat supraoptic nucleus.A triple-labeling immunofluorescence study
The aim of the present study was to examine quantitatively whether two calcium-binding proteins, calbindin D28k and calretinin, are localized in oxytocin and vasopressin neurons of the supraoptic nucleus of the male rat. We used a triple-labeling immunofluorescence method with a confocal laser scanning microscope. Of the oxytocin-labeled cells, 70% were stained for both calbindin D28k and calretinin, 15% were stained for only calbindin D28k, 13% were stained for only calretinin, and 2% were stained for neither protein. Of the vasopressin-labeled cells, 73% were stained for neither calbindin D28k nor calretinin, 21% were stained for only calbindin D28k, 4% were stained for only calretinin, and 2% were stained for both proteins. Calbindin D28k and calretinin have been shown previously to contribute to calcium homeostasis by buffering [Ca(2+)](i). Therefore, these findings suggest that most of the oxytocin neurons may have a higher Ca(2+)-buffering capacity than most of the vasopressin neurons.
Arai
R
Department of Anatomy, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan,
Jacobowitz
DM
Hida
T