Cardiac electrical activity in a genomically "humanized" chromogranin a monogenic mouse model with hyperadrenergic hypertension.

The prohormone chromogranin A (CHGA) is ubiquitously found in vesicles of adrenal chromaffin cells and adrenergic neurons, and it is processed to the hypotensive hormone peptide catestatin (CST). Both CHGA and CST regulate blood pressure and cardiac function. This study addresses their role in cardiac electrical activity.

Chromogranin a and the autonomic system: decomposition of heart rate variability and rescue by its catestatin fragment.

Chromogranin A (CHGA/Chga) has been implicated in the genesis of systemic hypertension and consequent cardiac abnormalities. Catestatin (CST) (human CHGA(352-372)) replacement reduces blood pressure elevation and increases baroreflex sensitivity in Chga knockout (KO) mice. Because of the dampened baroreflex sensitivity, we reasoned that KO mice would display altered heart rate variability (HRV).