DYNORPHIN 1-17 DELAYS THE VASOPRESSIN-INDUCED MOBILIZATION OF INTRACELLULAR CALCIUM IN CULTURED ASTROCYTES FROM THE RAT NEURAL LOBE

Citation
Cjc. Boersma et al., DYNORPHIN 1-17 DELAYS THE VASOPRESSIN-INDUCED MOBILIZATION OF INTRACELLULAR CALCIUM IN CULTURED ASTROCYTES FROM THE RAT NEURAL LOBE, Journal of neuroendocrinology, 5(5), 1993, pp. 583-590
Citations number
47
Categorie Soggetti
Neurosciences,"Endocrynology & Metabolism
ISSN journal
09538194
Volume
5
Issue
5
Year of publication
1993
Pages
583 - 590
Database
ISI
SICI code
0953-8194(1993)5:5<583:D1DTVM>2.0.ZU;2-7
Abstract
Opioid peptides are present in nerve terminals in the rat neural lobe where they partially coexist with vasopressin. Morphological findings suggest that these neuropeptides are released onto pituicytes, which i s in agreement with a possible role for the pituicyte in oxytocin and vasopressin release from the neural lobe. Pituicytes in culture respon d to vasopressin with a mobilization of calcium from intracellular sto res. In the present study this vasopressin induced increase in intrace llular free calcium levels was both delayed and decreased by pre-expos ure to dynorphin 1-17, while dynorphin 1-17 by itself did not affect b asal calcium levels. All effects of dynorphin 1-17 could be blocked wi th naloxone. The present results suggest that opioid receptors are pre sent on pituicytes and are coupled to a second messenger pathway by wh ich opioid peptides may inhibit inositol phosphate dependent calcium m obilization by other neuropeptides, such as vasopressin.