Short term vs long term dexamethasone treatment: Effects on rat diaphragm structure and function

David J. Prezant, Manoj Lal Karwa, B. Richner, D. Maggiore, E. I. Gentry, V. Chung, J. Cahill

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The effects of dexamethasone treatment duration (2.5 vs 10 weeks) on diaphragm myosin heavy chain isoforms, fiber types, and contractile characteristics were studied in male rats. Compared with ad libitum-fed and pair-fed controls, dexamethasone significantly decreased body weight, costal diaphragm weight, and the relative expression of myosin heavy chain isoform MHC-2B. Compared with pair-fed controls, the effect on MHC-2B expression was greater after l0 weeks than after 2.5 weeks. Type I and type II costal diaphragm fiber atrophy occurred, and type I1 fiber atrophy was greater after 10 weeks. Costal diaphragm-specific forces were not affected significantly by dexamethasone, regardless of the treatment duration or control group comparison. Fatigue resistance indexes were increased significantly after long term treatment compared with pair-fed controls and after both short term and long term treatment compared with ad libitum-fed controls. In conclusion, the effects of dexamethasone on MHC isoform phenotype expression, fiber type costal diaphragm atrophy, and fatigue resistance were dependent on treatment duration, with greater effects after long term (10 weeks) treatment.

Original languageEnglish (US)
Pages (from-to)267-280
Number of pages14
JournalLung
Volume176
Issue number4
DOIs
StatePublished - 1998

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Diaphragm
Dexamethasone
Atrophy
Protein Isoforms
Myosin Heavy Chains
Fatigue
Body Weight
Phenotype
Weights and Measures
Control Groups

Keywords

  • Corticosteroids
  • Myosin
  • Respiratory muscles

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Physiology

Cite this

Short term vs long term dexamethasone treatment : Effects on rat diaphragm structure and function. / Prezant, David J.; Karwa, Manoj Lal; Richner, B.; Maggiore, D.; Gentry, E. I.; Chung, V.; Cahill, J.

In: Lung, Vol. 176, No. 4, 1998, p. 267-280.

Research output: Contribution to journalArticle

Prezant, David J. ; Karwa, Manoj Lal ; Richner, B. ; Maggiore, D. ; Gentry, E. I. ; Chung, V. ; Cahill, J. / Short term vs long term dexamethasone treatment : Effects on rat diaphragm structure and function. In: Lung. 1998 ; Vol. 176, No. 4. pp. 267-280.
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