Comparative distribution of leucokinin and functionally related peptides in the nervous system of several insects

Abstract

Antisera against leucokinin IV were used to test for the presence of leucokinin-like peptides in the central nervous systems of Nauphoeta cinerea, Acheta domesticus, Schistocerca americana, Aedes aegypti, Manduca sexta and Apis mellifera. Leucokinin immunoreactive neurosecretory cells were found in the pars intercerebralis and pars lateralis of the brains of N. cinerea, A. domesticus, A. aegypti, but not in the brains of S. americana, M. sexta and A. mellifera. The neurohemal release sites were also very different among species. In contrast, the distribution patterns of leucokinin immunoreactive neurosecretory cells were very similar among abdominal ganglia of all six species. The identity of the leucokinin immunoreactive material in the brain, corpora cardiaca and abdominal ganglia of N. cinerea was shown by HPLC combined with ELISA. In N. cinerea and A. domesticus, leucokinin and vasopressin were found to co-localize in the same neurosecretory cells. In M. sexta, leucokinin and diuretic hormone co-localized in the same neurosecretory cells in abdominal ganglia, but not in the brain.