Glucocorticoid regulation of mRNA encoding (Na+K) ATPase alpha 3 and beta 1 subunits in rat brain measured by in situ hybridization.
The effect of glucocorticoids on (Na+K)ATPase mRNA synthesis was studied in 19 brain areas of adrenalectomized (ADX) rats untreated or receiving dexamethasone (DEX). For in situ hybridization, we employed a [35S]oligonucleotide probe for the alpha 3-subunit isoform, and a [3H]cDNA coding for the beta 1-subunit of the enzyme. Mean levels of grain density for the alpha 3 subunit mRNA of DEX-treated rats were significantly higher by a 't' test in medial septum, amygdala lateralis (AL) and medialis (AME), gyrus dentatus, CA4 hippocampal area, substantia nigra and periventricular gray, compared to untreated rats. For the beta 1-subunit, mean levels after DEX were significantly higher in AL and lateral preoptic area. In addition, the Kolmogorov-Smirnov test applied to frequency histograms of neuronal densities indicated a coordinate increase in alpha 3 and beta 1-subunit mRNA expression for the CA2 subfield and preoptic area medialis (POA MED). We conclude that (1) glucocorticoids are positive modulators of (Na+K)ATPase mRNA; (2) analysis of frequency histograms suggests that glucocorticoids promote in a few regions (AL, POA MED, CA2 subfield) a coordinate increase in the biosynthesis of the alpha 3 and beta 1-subunit mRNA. In 11 other areas stimulation occurs for one subunit mRNA only, whereas 5 areas were insensitive to glucocorticoid effects on this enzyme.
Grillo
C
C
Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental CONICET, Buenos Aires, Argentina.
Piroli
G
G
González
S L
SL
Angulo
J
J
McEwen
B S
BS
De Nicola
A F
AF
D000311:Adrenal Glands / Q000502:physiology*; D000315:Adrenalectomy; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology*; D005815:Genetic Code; D017403:In Situ Hybridization; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*
D010446:Peptide Fragments; D012333:RNA, Messenger; D003907:Dexamethasone; D000254:Sodium-Potassium-Exchanging ATPase