Crustacean Hyperglycemic Hormone in the Lobster Nervous System: Localization and Release from Cells in the Subesophageal Ganglion and Thoracic Second Roots

Crustacean hyperglycemic hormones (CHHs) are neuropeptides involved in the regulation of hemolymph glucose. The primary source of CHHs has been identified as the neurosecretory neurons of the eyestalk X-organ and its associated neurohemal organ, the sinus gland. We have identified another source of CHH-like peptides in the nervous system. With the use of immunocytochemistry, cells in the second roots of the thoracic ganglia have been observed to stain positively for CHH-reactive material. We also identified a pair of cells in the subesophageal ganglion that contain large amounts of CHH-reactive material. Depolarization of these cells with elevated potassium mediates a calcium-dependent release of CHH-like material from the ganglion as quantified with an enzyme-linked immunosorbent assay (ELISA).