Linked Life Data

8149585

Source:http://linkedlifedata.com/resource/pubmed/id/8149585

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-5-12
pubmed:abstractText
Endogenous opioids and opiate drugs inhibit nervous system maturation, in part, by affecting the growth of astrocytes. Opiates inhibit astrocyte proliferation and cause premature differentiation. The emerging importance of Ca2+ in astrocyte function prompted us to explore whether opiates might affect astrocyte development by altering Ca2+ homeostasis. Astrocyte-enriched cultures were derived from newborn ICR mouse cerebra. Quantitative fluorescent measurements of intracellular free Ca2+ ([Ca2+]i) using Fura-2 as well as fluo-3 and computer-aided image analysis showed that 1 microM morphine significantly increased [Ca2+]i in flat, polyhedral, glial fibrillary acidic protein (GFAP) immunoreactive astrocytes at 2 and 6 min, and at 72 h. Co-administration of 3 microM naloxone blocked morphine-dependent increases in [Ca2+]i. Treatment with 1 microM concentrations of the kappa-opioid receptor agonist, U69,593, but not equimolar amounts of mu ([D-Ala2,MePhe4,Gly(ol)5]enkephalin)- or delta ([D-Pen2,D-Pen5]enkephalin)-opioid receptor agonists, significantly increased [Ca2+]i in astrocytes. To assess the role of Ca2+ in morphine-induced astrocyte differentiation, untreated and 1 microM morphine-treated astrocyte cultures were incubated for 5 days in < 0.01, 0.3, 1.0, or 3.0 mM extracellular Ca2+ ([Ca2+]o), or incubated with 1.0 mM [Ca2+]o in the presence of 1 microM of the Ca2+ ionophore, A23187. The areas of single astrocytes were measured and there was a positive correlation between astrocyte area and [Ca2+]o. Morphine had an additive effect on area and form factor measures when [Ca2+]o was 1.0 mM. High [Ca2+]o (3.0 mM) alone mimicked the action of morphine. Morphine alone had no effect on astrocyte area in the presence of 3.0 mM Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0165-3806
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
76
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
189-96
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Opiates selectively increase intracellular calcium in developing type-1 astrocytes: role of calcium in morphine-induced morphologic differentiation.
pubmed:affiliation
Department of Clinical Science, University of Kentucky Medical Center, Lexington 40536.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't