Multiple members of the leucokinin neuropeptide family are present in cerebral and abdominal neurohemal organs in the cockroach Leucophaea maderae.
Two neurohemal organs of the cockroach Leucophaea maderae, the corpora cardiaca and the lateral heart nerve are known to contain leucokinin immunoreactive material. We examined the corpora cardiaca and the lateral heart nerve to establish whether these neurohemal organs store all 8 known leucokinin isoforms or if the leucokinins have a differential distribution. Extracts of corpora cardiaca and abdominal hearts with attached lateral heart nerve were separated on reversed phase high performance liquid chromatography (rpHPLC), then tested for leucokinin immunoreactivity by a radioimmunoassay (RIA) able to detect all 8 leucokinin isoforms. Extracts from brain and optic lobes were also separated and assayed in the RIA. Synthetic leucokinin 1-8 were subjected to rpHPLC and their different retention times established by RIA for reference. Leucokinin immunoreactive material originating from the corpora cardiaca and lateral heart nerves eluted in fractions corresponding to those of the synthetic leucokinin 1-8. In this study we have thus demonstrated that probably all 8 leucokinin isoforms are stored in the corpora cardiaca and the lateral heart nerve. These observations suggest that all 8 leucokinins are likely to be released as neurohormones into the circulation.
Department of Zoology, Stockholm University, Sweden.
A M
AM
Winther
C T
CT
Lundquist
D R
DR
Nässel
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003058:Cockroaches / Q000033:anatomy & histology / Q000737:chemistry*; D003429:Cross Reactions; D005260:Female; D007536:Isomerism; D008297:Male; D009479:Neuropeptides / Q000032:analysis*; D009490:Neurosecretory Systems / Q000737:chemistry*; D009842:Oligopeptides / Q000032:analysis; D011863:Radioimmunoassay
D009479:Neuropeptides; D009842:Oligopeptides