simple rule of thumb is
Calcium --> vasoconstriction (smooth muscle constriction) -- > must be Gq (alpha 1, v1)
rise in cAMP and cGMP both vasodilation (cAMP by inhibiting MLCK, cGMP by activating MLCP) so whoever causes vasodialation must increase either. cGMP is niche (NO, ANP) so most of the time it is rise in cAMP --> must be Gs (beta 2)
only exception is M3 it rises calcium (Gq) but in endothelial cells , not vascular smooth m. cells, so NO produced and causes vasodialation via rise in cGMP (again!)
HTN emergency, Sodium Nitroprusside. Unlike hydralazine a balanced vasodilator (vein = arteriol)
submitted by โdivya(75)
increase in cAMP (Gs) - beta2 - vasodilation
decrease in cAMP (Gi) - alpha2 - vasoconstriction
increase in IP3 DAG (Gq) - alpha1 - vasoconstriction
increase in cGMP - M3 - NO induced vasodilation