As part of a pathophysiology lecture in a fourth year course,you are informed that two different types of G-protein coupledreceptors are expressed on a human organ system. The activation ofreceptor-1 (R-1) causes an elevation in cyclic adenosinemonophosphate (cAMP) levels in the cells. While the activation ofreceptor-2 (R-2) causes an inhibition in the rise of cAMP levels inthe same cells.
Q1. Which G-protein alpha subunit is most likely associated withR-1 and R-2? 2 points R-1 = Q2.
You are further informed that activation of R-1 causesrelaxation of smooth muscles in the organ expressing thesereceptors.
What do you think could be the possible effect of R-2activation? 1 point
Q3. If the pathophysiology (clinical problem) in patients isexcessive muscle contraction and constriction of the tissue, howcan you target these two receptors to correct the underlyingdisorder? Note: Think in terms of agonist/antagonist for receptorsR-1 and R-2. 2 points
