Serum modulates cyclic AMP-dependent morphological changes in cultured neurohypophysial astrocytes.
The effects of serum on the morphological plasticity exhibited by pituicytes in explant cultures of the neurohypophysis of adult rats have been examined. Cultured pituicytes are normally nonstellate, protoplasmic, amorphous cells (< 25% are stellate with a distinct cell body and phase bright processes). After incubation (90 min) of pituicyte cultures in a HEPES buffered salt solution (HBSS) supplemented with isoproterenol or forskolin, the fraction of stellate pituicytes significantly increased. The increase in the fraction of stellate cells induced by isoproterenol was not reversed by subsequent incubation in isoproterenol-free HBSS for 90 min. In contrast, after stellation was induced in cultures by exposure to forskolin (90 min), the fraction of stellate cells was significantly reduced if these cultures were incubated in forskolin-free, serum (0.5%) supplemented HBSS for the same duration. Serum also blocked the increase in the fraction of stellate pituicytes induced by forskolin. These experiments suggest that serum components may have a significant role in controlling the plasticity of neuroglial relations in the neurohypophysis previously demonstrated in vivo.
Ramsell
K D
KD
Department of Pharmacology & Toxicology, Michigan State University, East Lansing 48824, USA.
Zhao
B G
BG
Baker
D
D
Cobbett
P
P
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D016895:Culture Media, Serum-Free; D000242:Cyclic AMP / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009473:Neuronal Plasticity / Q000187:drug effects; D010904:Pituitary Gland, Posterior / Q000166:cytology* / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley
D000318:Adrenergic beta-Agonists; D016895:Culture Media, Serum-Free; D005904:Glial Fibrillary Acidic Protein; D005576:Colforsin; D000242:Cyclic AMP; D007545:Isoproterenol