Neuropeptide-stimulated cyclic guanosine monophosphate immunoreactivity in the neurosecretory terminals of a neurohemal organ.
The neuropeptide eclosion hormone acts on the nervous system of the tobacco hornworm, Manduca sexta, to increase cyclic guanosine monophosphate (cGMP) levels. In this study I describe the localization of some of the sites where these increases occur. Prior to pupal ecdysis, eclosion hormone stimulates an increase in cGMP in a network of fibers in the transverse nerve of each abdominal ganglion. Double-label experiments with propidium iodide suggest that the cGMP immunoreactivity is primarily localized in neurosecretory nerve endings. The time course of the increase in cGMP immunoreactivity and its requirement for lipid metabolism is similar to that of the cGMP increase measured by radioimmunoassay. The cGMP response in the transverse nerve is stage-specific, occurring prior to pupal ecdysis and not prior to larval or adult ecdysis.
Arizona Research Labs Division of Neurobiology and Department of Biochemistry, The University of Arizona, Tucson 85721, USA.
D B
DB
Morton
D000818:Animals; D000918:Antibody Specificity; D006152:Cyclic GMP / Q000276:immunology* / Q000378:metabolism; D007150:Immunohistochemistry; D007301:Insect Hormones / Q000494:pharmacology*; D018402:Manduca / Q000502:physiology*; D018978:Molting / Q000502:physiology; D009036:Moths; D009411:Nerve Endings / Q000378:metabolism*; D009412:Nerve Fibers / Q000187:drug effects / Q000378:metabolism; D009420:Nervous System / Q000166:cytology; D009424:Nervous System Physiological Phenomena; D009479:Neuropeptides / Q000494:pharmacology; D009489:Neurosecretion / Q000502:physiology; D009490:Neurosecretory Systems / Q000187:drug effects* / Q000502:physiology; D011419:Propidium; D011679:Pupa / Q000187:drug effects / Q000502:physiology; D011863:Radioimmunoassay
D007301:Insect Hormones; D009479:Neuropeptides; D011419:Propidium; C042645:eclosion hormone; D006152:Cyclic GMP