Dopamine and Serotonin Receptors Cooperatively Modulate Pacemaker Activity of Intestinal Cells of Cajal.

Dopamine and Serotonin Receptors Cooperatively Modulate Pacemaker Activity of Intestinal Cells of Cajal.
Chin J Physiol. 2018 Oct 31;
Authors: Liu HN, Hirata H, Okuno Y, Okabe M, Furukawa K
Abstract
The neurotransmitters dopamine and serotonin control the peristaltic movement of the gut
that consists of propagating waves of rhythmic contraction and relaxation. While intestinal cells of
Cajal (ICC) serve as a pacemaker in the gut, the effect of dopamine on the pacemaker activity of ICC
remains unknown. Here, we report that together with serotonin receptors, the dopamine receptor D₂
contributes to maintaining [Ca²⁺]i oscillations in ileum ICC. When the antagonist for the D₂ receptor
was applied to the cell cluster or the tissue culture prepared from muscle layers of the mouse small
intestine, the amplitude of [Ca²⁺]i oscillations in ICC declined after a transient increase. On the other
hand, treatment with the D₂ receptor agonist decreased the frequency of [Ca²⁺]i oscillations in ICC.
These results suggest that basal level activity of the D₂ receptor is crucial for maintaining [Ca²⁺]i
oscillations in ICC. The decrease in the [Ca²⁺]i oscillation amplitude upon the D₂ receptor antagonist
treatment was abrogated by antagonizing the serotonin receptor 5HT₂, indicating an inhibitory effect
of the 5HT₂ receptor on the [Ca²⁺]i oscillations. Together with the finding that treatment with the
antagonist for the se...

Source: The Chinese Journal of Physiology - November 3, 2018 Category: Physiology Tags: Chin J Physiol Source Type: research