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Effect of dexamethasone pretreatment on the dexamethasone-dependent induction of tyrosine aminotransferase activity in primary cultured rat hepatocytes.
Biol Pharm Bull. 1998 Oct; 21(10):1009-12.BP

Abstract

The effect of dexamethasone (Dex) pretreatment on the Dex-dependent induction of tyrosine aminotransferase (TAT) activity was studied in primary cultured rat hepatocytes. The extent of the Dex-dependent induction of TAT activity decreased during culture in untreated cells. Dex pretreatment prevented this decrease. A Scatchard plot analysis of the results of a [3H]Dex binding assay showed that hepatocytes cultured for 2.5 h possessed both high and low affinity binding sites in their cytosols. The number of both high and low affinity binding sites decreased during culture for a further 24 h in untreated cells. Dex pretreatment partly prevented the decrease in low affinity binding sites but had no effect on the decrease in high affinity binding sites. These results show that Dex pretreatment counteracts the usual decrease in the inducibility of TAT activity, and suggest that this action of Dex may be due to the maintenance of low affinity binding sites. These results also suggest that low affinity binding sites could possibly mediate the biological response to Dex.

Authors+Show Affiliations

Nimi S
Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, Tokyo, Japan.
Yamaguchi T
No affiliation info available
Hayakawa T
No affiliation info available

MeSH

AnimalsBinding SitesCells, CulturedDexamethasoneEnzyme InductionGlucocorticoidsKineticsLiverMaleRatsRats, WistarReceptors, GlucocorticoidTritiumTyrosine Transaminase

Pub Type(s)

Journal Article

Language

eng

PubMed ID

9821801

Citation

Nimi, S, et al. "Effect of Dexamethasone Pretreatment On the Dexamethasone-dependent Induction of Tyrosine Aminotransferase Activity in Primary Cultured Rat Hepatocytes." Biological & Pharmaceutical Bulletin, vol. 21, no. 10, 1998, pp. 1009-12.
Nimi S, Yamaguchi T, Hayakawa T. Effect of dexamethasone pretreatment on the dexamethasone-dependent induction of tyrosine aminotransferase activity in primary cultured rat hepatocytes. Biol Pharm Bull. 1998;21(10):1009-12.
Nimi, S., Yamaguchi, T., & Hayakawa, T. (1998). Effect of dexamethasone pretreatment on the dexamethasone-dependent induction of tyrosine aminotransferase activity in primary cultured rat hepatocytes. Biological & Pharmaceutical Bulletin, 21(10), 1009-12.
Nimi S, Yamaguchi T, Hayakawa T. Effect of Dexamethasone Pretreatment On the Dexamethasone-dependent Induction of Tyrosine Aminotransferase Activity in Primary Cultured Rat Hepatocytes. Biol Pharm Bull. 1998;21(10):1009-12. PubMed PMID: 9821801.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effect of dexamethasone pretreatment on the dexamethasone-dependent induction of tyrosine aminotransferase activity in primary cultured rat hepatocytes. AU - Nimi,S, AU - Yamaguchi,T, AU - Hayakawa,T, PY - 1998/11/20/pubmed PY - 1998/11/20/medline PY - 1998/11/20/entrez SP - 1009 EP - 12 JF - Biological & pharmaceutical bulletin JO - Biol Pharm Bull VL - 21 IS - 10 N2 - The effect of dexamethasone (Dex) pretreatment on the Dex-dependent induction of tyrosine aminotransferase (TAT) activity was studied in primary cultured rat hepatocytes. The extent of the Dex-dependent induction of TAT activity decreased during culture in untreated cells. Dex pretreatment prevented this decrease. A Scatchard plot analysis of the results of a [3H]Dex binding assay showed that hepatocytes cultured for 2.5 h possessed both high and low affinity binding sites in their cytosols. The number of both high and low affinity binding sites decreased during culture for a further 24 h in untreated cells. Dex pretreatment partly prevented the decrease in low affinity binding sites but had no effect on the decrease in high affinity binding sites. These results show that Dex pretreatment counteracts the usual decrease in the inducibility of TAT activity, and suggest that this action of Dex may be due to the maintenance of low affinity binding sites. These results also suggest that low affinity binding sites could possibly mediate the biological response to Dex. SN - 0918-6158 UR - https://www.unboundmedicine.com/medline/citation/9821801/Effect_of_dexamethasone_pretreatment_on_the_dexamethasone_dependent_induction_of_tyrosine_aminotransferase_activity_in_primary_cultured_rat_hepatocytes_ L2 - https://medlineplus.gov/steroids.html DB - PRIME DP - Unbound Medicine ER -