O. Shimada et al., DETECTION OF DEOXYRIBONUCLEASE-I IN A HORMONE-SECRETORY PATHWAY OF PITUITARY-CELLS IN HUMANS AND RATS, Cell structure and function, 23(2), 1998, pp. 49-56
High levels of deoxyribonuclease I (DNase I) were detected in the cyto
plasm of hormone-secreting cells in anterior and intermediate lobes of
human and rat pituitary glands. Tissue homogenate fractions of anteri
or and intermediate pituitary lobes showed strong DNase I-specific enz
ymatic activity. Immunofluorescence, with several specific antibodies
against human and rat DNase I, indicated strong immunoreactivity in th
e cytoplasm of hormone-secreting cells within the gland. In situ hybri
dization demonstrated high levels of DNase I mRNA in the cells. By imm
unoelectron microscopy, immunogold particles were found in the rough e
ndoplasmic reticulum, Golgi apparatus and secretory granules. Exocytot
ic secretory granules were also immunopositive. These results indicate
that endocrine cells in the pituitary gland synthesize and secrete DN
ase I together with their respective pituitary hormones.