Chromaffinity, uranaffinity and argentaffinity of small granule-containing (SGC) cells in rat superior cervical ganglia

Abstract

A systemic examination on the small granule-containing (SGC) cells in rat superior cervical ganglia was conducted by conventional and cytochemical electron microscopy including chromaffin, argentaffin and uranaffin reactions. According to the fine structure of dense cored vesicles (DCVs) in the cytoplasm, three types of small granule-containing (SGC) cells were revealed - Type 1: 90 - 160 nm vesicles with cores of moderate or low electron density; Type 11: 130 - 330 nm vesicles, polymorphic with highly electron dense cores; Type 111: elongated vesicles (170 nm x 60 nm) with cores of moderate to low electron density. The majority of SGC cells were the Type 1 cells (78%) and Type 11 and 111 cells made up 13% and 9% of SGC cell population, respectively. Cytochemical results demonstrated that only the Type 11 cells displayed a positive chromaffin reaction and al1 three types of SGC cells showed argentaffinity and uranaffinity. The present study is the first to demonstrate the argentaffin reaction at ultrastructural level in SGC cells of sympathetic ganglia. Based on the results of the present study we also concluded that (1) the DCVs of Type 11 SGC cells contained noradrenaline and (2) biogenic amines and nucleotides (ATPs) coexisted in the DCVs of al1 three types of SGC cells.