An Antisense Oligodeoxynucleotide to Lipocortin 1 Reverses the Inhibitory Actions of Dexamethasone on the Release of Adrenocorticotropin from Rat Pituitary Tissue in Vitro

A. D. Taylor
1997 Endocrinology  
Our previous studies have demonstrated that lipocortin 1 (LC1, also called annexin 1) is an important mediator of glucocorticoid action in the neuroendocrine system, particularly with regard to the powerful inhibitory actions of the steroids on the secretion of ACTH and its hypothalamic releasing hormones. In the present study, we have used an antisense oligodeoxynucleotide (ODN) unique to LC1 to investigate further the role of this protein in the regulatory effects of dexamethasone on ACTH
more » ... thasone on ACTH release in vitro from rat anterior pituitary cells. Pituitary cells dispersed with collagenase retained their functional and morphological integrity in vitro and sequestered ODNs in a time-dependent manner from the incubation medium. LC1 was readily detected in the cells by Western blot analysis or by immunoprecipitation/autoradiography after preloading with 35 S-methionine/ cysteine; the bulk of the protein was contained within an intracellular pool but a small amount was attached to the outer cell surface (pericellular). Dexamethasone (100 nM, 2.5 h) initiated de novo synthesis of LC1; it also increased the amount of LC1 in the pericellular pool
doi:10.1210/en.138.7.2909 pmid:9202235 fatcat:qhfme5voo5f6fhp7clorusneqm