Editing Gattone's "Inhibition of renal cyst disease development and progression by a vasopressin V2 receptor antagonist" 2003

===Abstract===
*PKD had no treatment at the time of publishing.
*There are two forms: autosomal recessive PKD (ARPKD) and nephronophthisis (NPH).
**Both have characteristic collecting duct cyst formation.
*They used an animal model of the disease.
*They administered a drug-candidate molecule.
*We already knew that cAMP levels were high in the diseased state and that they contributed to cyst formation through the vasopressin V2 receptor.
*OPC31260 was the drug-candidate they applied.
*OPC31260 binds to vasopresin V2 receptor (VPV2R) as an antagonist to it's activity.
*Upon treatment they saw halting of disease progression or even regression of the disease state.

===Figure 1: Polycystin pathway===
*The pathway starts with proteins on the primary follicle that sense extracellular signals.
*These detectors activate proteins that increase intracellular Ca concentrations through the release of Ca fromt he ER and by moving Ca in from extracellular fluid.
*When Ca rises:
**adenylyl cyclase VI is activated which generates cAMP,
**cAMP-dependent PDE
*Therefore cAMP levels rise in the cell.

===Figure 2: Metrics===
*They measured levels of cAMP, VPV2R, and aquaporin in diseased and wildtype mice.
*This showed the expected increase in cAMP in diseased state, the decrease in cAMP after intervention, and the steady levels of VPV2R.
*Aquaporin levels were measured because it is positively regulated by cAMP and VPV2R.

===Figure 3: Development and Progression===
*They measured things like kidney weight and renal fibrosis volume to show that disease development was decreased upon intervention and also that disease progression was decreased upon intervention.

===Figure 4: Histology===
*They show there are fewer and smaller cysts in the treated subjects.