Pharmacological Analysis of P2Y Purinergic Receptors That Modulate the Rat Vasopressor Sympathetic Tone

Background/Objectives: Adenosine 5'-O-(β-thio)-diphosphate (ADPβS) is a stable analogue of adenosine diphosphate (ADP). In pithed rats, ADPβS produces (i) inhibition of both the cardioaccelerator sympathetic tone (via prejunctional P2Y12/P2Y13 receptors) and the vasodepressor sensory CGRPergic tone (via prejunctional P2Y1 receptors) and (ii) vasodepressor/vasodilator responses via endothelial P2Y1 receptors, and vasopressor/vasoconstrictor responses via P2Y1/P2Y12/P2Y13 receptors. This study pharmacologically investigates whether P2Y1, P2Y12, and/or P2Y13 receptors modulate the vasopressor sympathetic tone using ADPβS.

Methods

A total of 126 male Wistar rats were pithed and classified into two groups to produce vasopressor responses by (i) spinal (T7-T9) electrical stimulation of the sympathetic vasopressor tone (0.03-3 Hz; n = 102) and (ii) intravenous (i.v.) boluses of noradrenaline (0.03-3 μg/kg; n = 24).