Primary Screening of Selective Agonists and Adrenoreceptor Blockers on A New Paramecium Caudatum Model

The study investigated the impact of selective agonists and antagonists of adrenergic receptors at different concentrations on the behavior of the unicellular organism Paramecium caudatum. It was demonstrated that exposure to methoxamine at a concentration of 10-3 M increases the movement speed of Paramecium caudatum cells but reduces the number of motile cells by activating various intracellular processes. The presence of phenylephrine at a concentration of 10-3 M in the environment decreases motor activity and exhibits similar effects to adrenaline. The introduction of terbutaline at a concentration of 10-3 M leads to a sharp and prolonged increase in cell movement speed and overall activity, while the addition of dobutamine at a concentration of 10-3 M reduces motor activity. The study also showed the effects of selective blockers prazosin and atenolol at a concentration of 10-5 M, which manifested in the complete correction of the effects induced by the corresponding selective agonists on all investigated parameters of motor activity.