Title: Acidosis-induced metallothionein (MT) mRNA expression in neonatal rat primary astrocyte cultures.
Authors: Aschner, M; Stark, S; Vrana, K E; Conklin, D R
Published In Neurotoxicology, (1998 Apr)
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.
PubMed ID: 9553959
MeSH Terms: Acidosis/metabolism*; Animals; Animals, Newborn; Astrocytes/metabolism*; Cells, Cultured; Cerebral Cortex/metabolism; Comparative Study; Metallothionein/genetics; Metallothionein/metabolism*; RNA, Messenger/biosynthesis*; Rats; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.