Hindlimb extensor reflex of spinal rats given tranylcypromine stereoisomers

The hindlimb extensor reflex of reserpinized, spinal rats was used to determine whether tranylcypromine (dl-TCP) and its stereoisomers (d-TCP and l-TCP) after tryptaminergic neurotransmission. dl-TCP and d-TCP caused an extensor reflex while l-TCP failed to cause a reliable extensor reflex. Neither H 22/54 nor nialamide affected the extensor reflex in rats given dl-TCP, while H 22/54 reduced the reflex in rats given d-TCP. The results suggest that dl-TCP and d-TCP have direct as well as indirect actions on tryptaminergic neurotransmission.