title: Further characterization of the impact of ethanol on βLH: alterations in polyribosome association of βLH mRNA.
abstract: We have previously reported a decrease in Luteinizing Hormone (LH) levels in serum afterin vivo acute ethanol exposure in male rats. Accompanying these changes, a rapid and marked decrease of β-LH mRNA was observed. A similar decrease was not detected in the common α-subunit or β-FSH mRNA. The studies presented here examined the possible mechanisms of decreasing β-LH mRNA by using S1 nuclease protection assay to evaluate the effect of acute ethanol exposure on the levels of β-LH heteronuclear RNA (hnRNA). There was no significant difference detected in the level of β-LH hnRNA after ethanol exposure. Polysome distribution analysis was used to evaluate the association and disassociation of β-LH mRNA with polyribosomes since non-polyribosome associated mRNA may be more vulnerable to degradation by RNAases. The results indicated a decrease in the association of the β-LH mRNA with polysomes following acute ethanol exposure. This decrease in polyribosome association would increase the exposure of the β-LH transcript making it more susceptible to RNases. We conclude that the decrease in steady-state β-LH mRNA levels after ethanol exposure occurs because of increasing degradation of the transcript rendered vulnerable by displacement from polysomes and not through a decreased transcriptional rate.
authors.affiliation: Department of Molecular and Cellular Biochemistry, Loyola University of Chicago, Maywood, Illinois, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Halloran
authors.forename: M A
authors.initials: MA
authors.lastname: Emanuele
authors.forename: N V
authors.initials: NV
authors.lastname: Emanuele
authors.forename: J J
authors.initials: JJ
authors.lastname: Tentler
authors.forename: M R
authors.initials: MR
authors.lastname: Kelley