title: Modulation of thyroid hormone receptors, TRα and TRβ, by using different doses of triiodothyronine (T3) at different times.
abstract: OBJECTIVE
  To examine the effect of different doses of triiodothyronine (T3) on mRNA levels of thyroid hormone receptors, TRα and TRβ, at different times.
  
  
  METHODS
  3T3-L1 adipocytes were incubated with T3 (physiological dose: F; supraphysiological doses: SI or SII), or without T3 (control, C) for 0.5, 1, 6, or 24h. TRα and TRβ mRNA was detected using real-time polymerase chain reaction.
  
  
  RESULTS
  F increased TRβ mRNA levels at 0.5h. After 1h, TRα levels increased with F and SI and TRβ levels decreased with SII compared with C, F, and SI. After 6h, both genes were suppressed at all concentrations. In 24h, TRα and TRβ levels were similar to those of C group.
  
  
  CONCLUSIONS
  T3 action with F began at 1h for TRα and at 0.5h for TRβ. These results suggest the importance of knowing the times and doses that activate T3 receptors in adipocytes.
authors.affiliation: Department of Internal Clinic, Botucatu Medicine School, São Paulo State University, Botucatu, SP, Brazil. miriane.deoliveira@yahoo.com.br
authors.forename: Miriane de
authors.initials: Md
authors.lastname: Oliveira
authors.forename: Renata de Azevedo Melo
authors.initials: Rde A
authors.lastname: Luvizotto
authors.forename: Regiane Marques Castro
authors.initials: RM
authors.lastname: Olimpio
authors.forename: Maria Teresa de
authors.initials: MT
authors.lastname: Sibio
authors.forename: Carolina Biz Rodrigues
authors.initials: CB
authors.lastname: Silva
authors.forename: Sandro José
authors.initials: SJ
authors.lastname: Conde
authors.forename: Carlos Roberto
authors.initials: CR
authors.lastname: Padovani
authors.forename: Célia Regina
authors.initials: CR
authors.lastname: Nogueira
mesh_terms: D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D016525:Antigenic Modulation / Q000276:immunology*; D002460:Cell Line; D004334:Drug Administration Schedule; D012333:RNA, Messenger / Q000032:analysis; D037021:Thyroid Hormone Receptors alpha / Q000235:genetics / Q000378:metabolism*; D037042:Thyroid Hormone Receptors beta / Q000235:genetics / Q000378:metabolism*; D014284:Triiodothyronine / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D012333:RNA, Messenger; D037021:Thyroid Hormone Receptors alpha; D037042:Thyroid Hormone Receptors beta; D014284:Triiodothyronine