Autocoids (Histamine and Serotonin)
The H3 receptor agonist exhibits all of the following actions EXCEPT (AIIMS Nov 2012)
|A||Inhibition of H, receptor induced wakefulness|
|B||Increase in H, mediated gastrin secretion Drugs used for prophylaxis of migraine is/are|
|C||Inhibition of H, mediated bronchoconstriction|
|D||Negative chronotropic effect on atria|
H3 receptors act as pre-synaptic receptors and decrease the release of histamine and other neurotransmitters. These an-tagonize HI mediated wakefulness and bronchoconstriction. These also decrease gastrin release and produce negative chronotropic effect.