Angiotensin II stimulates sperm motility

The physiological factors which induce and maintain mammalian sperm maturation and motility generally remain unclear, although several agents are known to be involved. We recently described the application of immunocytochemical and immunoblotting methods to identify the angiotensin II type 1 (AT1) receptor in the tails of ejaculated rat and human sperm, and gave evidence to show that angiotensin II may promote sperm motility. These data are extended here by the application of a computerised sperm tracking system (the Hobson Sperm Tracker) to demonstrate that AII has actions on specific motility parameters, including curvilinear velocity, straight line velocity, and amplitude of lateral head movement. Since local tissue renin-angiotensin systems are present in both male and female tracts, the data suggest that angiotensin II has a role in the maintenance of sperm function and fertility.