NOS immunoreactivity was assayed in CNS and peripheral tissues of the sea s
lugs Pleurobranchaea californica, Tritonia diomedea and Aplysia californica
using different antisera against mammalian nitric oxide synthase in Wester
n blots. Polyclonal anti-nNOS labeled at 250, 185, 170, 155, 100, 75, and 6
5 kD in extracts of Pleurobranchaea CNS, salivary gland and esophagus but n
ot of gills or muscle. The labeling pattern for Tritonia in bands at 250, 2
00, 120/110, 100, 69, 65, and 60 kD differed somewhat. Anti-nNOS labeling i
n Aplysia was markedly different, with bands labeled only at 69 and 60 kD i
n CNS extracts, and at 200, 190, 69 and 60 kD in salivary and esophagus ext
racts. The wide variation in NOS immunoreactivity is consistent with specie
s differences in tissue localization and biochemical properties of mollusca
n NOS isoforms. (C) 1999 Academic Press.