The word proctolin first appeared in the literature in 1975 when, in two
landmark papers, the late B. E. Brown and his collaborator A. N. Starratt
* Dedicated to the late Brian Ellrnan Brown, 1930-1977.
ADVANCES IN INSECT PHYSIOLOGY VOL. IY
A// righcs of reproduction in any form reJerved
reported on the isolation (Brown and Starratt, 1975) and the primary
structure (Starratt and Brown, 1975) of an insect pentapeptide (Arg-TyrLeu-Pro-Thr).
This peptide was named proctolin and was suggested as a
candidate transmitter in insects (Brown, 1975). The history of proctolin’s
identification, however, began almost twenty years ago when B. E. Brown
characterized a myotropic factor in the gut of the cockroach, Periplaneta
arnericana (Brown, 1967). This factor (referred to then as “the gut-factor”)
produced a slow graded contraction of the longitudinal muscles of the
proctodeum (Brown, 1967) and appeared to satisfy some of the criteria
characterizing neuromuscular transmitters.