Annexin-1 (lipocortin-1)-immunoreactivity in the folliculo-stellate cells of rat anterior pituitary: The effect of adrenalectomy and corticosterone treatment on its subcellular distribution

H. Ozawa
M. Miyachi
I. Ochiai
S. Tsuchiya
J. F. Morris
M. Kawata

In the pituitary gland
 annexin-1 (lipocortin-1) located in folliculo-stellate (FS) cells has been advocated as one of the candidates for paracrine agents produced by FS cells that modulate the release of pituitary hormones. However
 the expression and distribution pattern of annexin-1 in FS cells under different circulating corticosteroid conditions has not been examined. Thus
 by means of pre-embedding immunoelectron microscopy
 we investigated the expression of annexin-1 in FS cells under different corticosteroid conditions. Annexin-1-immunoreactivity was observed in the cytoplasm especially intense immunoreactivity was detected in the follicle surface of FS cells under control conditions. After adrenalectomy
 annexin-1-immunoreactivity almost disappeared
 but the immunoreactivity recovered with corticosterone replacement. The expression of glucocorticoid receptor immunoreactivity in the nucleus of FS cells also showed a similar pattern to annexin-1 associated with the changes in the corticosteroid conditions. However
 S-100 immunoreactivity
 a marker for FS cells
 was not changed whatever the corticosteroid conditions. These results confirm that glucocorticoids regulate the annexin-1 expression and demonstrate the translocation of annexin-1 from intracellular to pericellular sites in the FS cells of the rat anterior pituitary gland.

Journal of Neuroendocrinology

14

8

10.1046/j.1365-2826.2002.00814.x

https://doi.org/10.1046/j.1365-2826.2002.00814.x
https://www.ncbi.nlm.nih.gov/pubmed/12153464