Revista Médica del Hospital General de México (Jul 2023)
Fast kinetics of fundamental aortic contraction to phenylephrine compared to KCl only in male prepubertal and adult rats
Abstract
Background: Phenylephrine (PHE) produces higher aortothoracic contractile tension with endothelium (T[ON]) compared to potassium chloride (KCl). Both are exponential triphasic responses (Φ1, Φ2, Φ3) but their kinetics have not been compared with the time constant (τ in s). Goal. To study the triphasic T[On] kinetics (τ: Φ1, Φ2(fundamental) and Φ3) of 1μM PHE vs 40mM KCl. Material and methods: We compared numerical values of τ1, τ2, τ3 of the T[On] of prepubertal male Wistar rats (without established reproductive capacity) with adult male ones. Results: Φ2 showed higher gain (g), shorter delay time (s), and faster kinetics of T[On] at PHE than at KCl. Conclusions: In the time course of T[On] only the fundamental exponential phase was faster with PHE than with KCl.
