How are a2 adrenergic receptors?

Location (presynaptic nerve endings, on other cells like b cells of pancreas, control neuromediator and insulin output respectively. stimulation gives feedback inhibition of ongoing release of NE from stimulated adrenergic neurons, inhibitory action decreases further output of adrenergic neurons and serves as a local modulation mechanism for reducing sympathetic neuromediator output when high sympathetic activity. They are also found in presynaptic parasympathetic neurons) Second messenger (inhibition of adenylyl cyclase and decrease in intracellular cAMP)