Key Points
- To determine whether alterations in myosin heavy chain messenger RNA levels correspond to overall RNA synthesis during the development and reversal of pressure-overload-induced myocardial hypertrophy.
- Extracted total RNA and analyzed myosin heavy chain (MHC) mRNA from rat myocardium.
- Evaluated myocardial tissue during the progression of pressure-overload hypertrophy and following the surgical relief of overload during regression.
- MHC mRNA content increased in direct proportion to total RNA expansion during the establishment of myocardial hypertrophy.
- Relief of pressure overload caused MHC mRNA to decline significantly faster and to a greater extent than total RNA, reflecting halted transcription and rapid message degradation.
Structured PICO
PPopulationRat heart model of pressure-overload induced myocardial hypertrophy
IInterventionPressure-overload (development of hypertrophy) and relief of pressure-overload (regression)
OOutcomeAmount of myosin heavy chain (MHC) mRNA relative to total RNAsurrogate
The development and regression of myocardial hypertrophy are driven by changes in mRNA for contractile proteins, specifically myosin heavy chain.