Age-related regional differences in cardiac nerve growth factor expression

Area of Science:

• Cardiovascular Physiology
• Neurobiology
• Aging Research

Background:

• Age is a key risk factor for cardiovascular diseases.
• The elderly exhibit increased sympathetic nervous system tone.
• Nerve growth factor (NGF) enhances cardiac sympathetic activity.

Purpose of the Study:

• To investigate age-related changes in NGF expression in rat cardiomyocytes.
• To determine regional differences in NGF expression within the heart (atria vs. ventricles).
• To explore the role of NGF in age-associated autonomic tone shifts.

Main Methods:

• Utilized a rat model across three age groups: neonatal, young, and old.
• Isolated cardiomyocytes from left/right atria (LA/RA) and left/right ventricles (LV/RV).
• Quantified NGF and TrkA receptor expression at both mRNA and protein levels.

Main Results:

• NGF levels were consistently lower in atria compared to ventricles across all ages.
• Atria showed increased NGF expression with age (neonatal < young < old).
• Ventricles exhibited decreased NGF from neonatal to young, then increased from young to old, with highest levels in neonates.
• Tyrosine kinase A receptor (TrkA) expression was highest in old atria and young ventricles.

Conclusions:

• NGF expression patterns change significantly with age and vary regionally in the heart.
• These age- and region-specific NGF changes likely contribute to the altered cardiac autonomic tone observed in older individuals.