RESUMO
Effects of gadolinium chloride, an inhibitor of stretch-activated channels, on the responses of slowly adapting receptors (SARs) and rapidly adapting receptors (RARs) to hyperinflation were investigated. The increase in activity of RARs resulting from sustained elevations of left atrial pressure (LAP) was also assessed with gadolinium chloride application. Action potentials (AP) of SARs and RARs during hyperinflation were recorded from the vagus nerve of anesthetized New Zealand White rabbits before and after application of gadolinium chloride (20mM) directly on the receptor area of the nerve endings. There was a significant reduction of activity in SARs (n = 9) and RARs (n = 7) after application of gadolinium chloride. Activity of RARs (n = 6) increased when the LAP was elevated by 5 and 10 mmHg. This effect was abolished after gadolinium chloride was applied to receptor endings and the activity was restored when gadolinium chloride was removed. This suggests that stretch-activated channels play a role in SARs and RARs activity.
