title: Acidosis-induced metallothionein (MT) mRNA expression in neonatal rat primary astrocyte cultures.
abstract: Metallothionein (MT) mRNA levels were determined following exposure of neonatal rat primary astrocyte cultures to acidosis. Astrocyte total RNA was probed on northern blots with [alpha 32 P]dCTP-labeled synthetic cDNA probes specific for rat MT isoform mRNAs. The probe for MT-I mRNA hybridized to a single mRNA with a size appropriate for MT, approximately 550 nucleotides. MT-I mRNA levels in astrocyte monolayers exposed to pH 6.5 and 6.0 for 3 or 6 hours were unchanged compared with MT-I mRNA levels in control cultures exposed to pH 7.4. In contrast, 9 hour exposure of astrocytes to pH 6.5 and 6.0 led to a significant increase in MT-I mRNA transcripts compared with controls maintained at pH 7.4 (p < 0.001 and p < 0.02, respectively). A probe for MT-II mRNA that hybridizes to a single mRNA (450 nucleotides) was also used to determine the effect of acidosis on astrocyte MT-II mRNA transcripts. Although statistical significance was not attained, a similar trend was noted, with a 9 hour exposure to pH of 6.5 and 6.0 resulting in increased astrocytic expression MT-II mRNA compared with control cells maintained at pH 7.4. Acidosis was also associated with a pH-dependent increase in astrocytic volume. Accordingly, acidosis is invoked as an added stimulus to stress factors associated with the induction of astrocytic MT mRNA transcripts.
authors.affiliation: Department of Physiology and Pharmacology, Bowman Gray School of Medicine, Winston-Salem, NC 27157-1083, USA.
authors.forename: M
authors.initials: M
authors.lastname: Aschner
authors.forename: S
authors.initials: S
authors.lastname: Stark
authors.forename: K E
authors.initials: KE
authors.lastname: Vrana
authors.forename: D R
authors.initials: DR
authors.lastname: Conklin
mesh_terms: D000138:Acidosis / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000378:metabolism; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats
chemical_list: D012333:RNA, Messenger; D008668:Metallothionein