Mathematical modeling improves EC50 estimations from classical dose-response curves

Area of Science:

• Pharmacology
• Cardiovascular Physiology
• Computational Biology

Background:

• The beta-adrenergic response is crucial for heart function but is impaired in heart failure.
• In vitro studies use the half-maximal effective concentration (EC50) to measure ligand response.
• Previous studies observed decreasing responses at high adrenaline concentrations in chicken heart tissue.

Purpose of the Study:

• To develop a mathematical model to interpret the full dose-response curve of beta-adrenergic stimulation in heart tissue.
• To re-interpret previously obtained datasets using a novel mathematical approach.
• To obtain more accurate estimates of EC50, especially when steady-state measurements are not feasible.

Main Methods:

• Applied a mathematical modeling approach to analyze the full dose-response curve of adrenaline on chicken heart contraction force.
• The model accounts for non-steady-state conditions arising from short resting times between agonist concentrations.
• Utilized steady-state simulations and time-resolved data for refined EC50 estimation.

Main Results:

• The developed model predicts that short resting times affect dose-response characterization.
• Model-based EC50 estimates (180-525 nm) are higher than classically interpreted values (46-191 nm).
• Mathematical modeling allows for accurate EC50 estimation even without experimental steady-state measurements.

Conclusions:

• Mathematical modeling provides a more accurate interpretation of beta-adrenergic dose-response curves.
• This approach refines EC50 estimation by considering dynamic physiological conditions.
• The findings enable re-interpretation of existing data and improve understanding of beta-adrenergic function in the heart.