Facilitation of lordosis in the female rat by midbrain central gray infusions of substance P

Infusions of LHRH ( 50ng ), and Substance P ( 50ng, 500ng, and lug ) into the midbrain central gray led to a prompt facilitation of lordosis which was evident as early as 5 minutes post infusion, and depending on the dose had a duration of at least 120 minutes. Despite an apparent trend, different doses of substance P did not produce a signifcant dose-dependent facilitation of lordosis. Doses of substance P ( 50ng ), and LHRH ( 50ng ), produced effects on lordosis scores, but did not differ between tests. Administration of an anti-serum raised in rabbits against substance P failed to produce a statistically significant reduction in lordosis scores, although here too, a trend was evident.