They found that the inhibitory effect of κ-OR stimulation on β-adrenergic signaling was attenuated in the ventricular myocytes of 13-week-old spontaneously hypertensive rats with established hypertension, but not in younger rats before hypertension was fully developed, indicating that the blunted crosstalk between κ-ORs and β-ARs may contribute to the maintenance but not the initiation of hypertension in this model. The gene discussed is OPRK1; the disease is Hypertension.