Central and peripheral apelin receptor distribution in the mouse: Species differences with rat

► APJ is well characterized in the rat but is not well described in mouse tissues. ► We show the first detailed anatomical distribution of APJ mRNA and protein in the mouse. ► There is a species difference in central APJ distribution and in the pituitary gland. APJ distribution in peripheral tissues appears comparable between rat and mouse. ► The apelin system may have a more wide-ranging central role in the rat than the mouse.