Attempts to demonstrate the existence of a serotonin complex in suspensions of lysed rabbit
platelets have not been successful. However, kinetic studies of serotonin uptake by platelets
of normal and reserpine-treated guinea pigs indicate that serotonin is taken up by active
transfer. Reserpine appears to act by blocking the active transport. Norepinephrine and
epinephrine, but not bufotenine, can also be taken up in platelets in vitro by a process which
is blocked by reserpine.