title: Ultrastructural changes associated with K+-evoked peptide secretion from a neurohemal organ of the crab, Cardisoma carnifex.
abstract: Electron-microscopic comparison of K+-stimulated and unstimulated crab sinus glands reveals significant differences in neurosecretory terminal morphology. Sinus glands exposed to elevated K+ saline for increasing periods of time show increasing numbers of exocytotic release profiles, vacuoles, and multilamellate bodies, and a decrease in the number of microvesicles within 10 micron of release sites. These morphological changes are well correlated with secretion of red-pigment-concentrating hormone, as determined by bioassay of perfusate from the individual preparations.
mesh_terms: D000818:Animals; D003386:Brachyura; D007447:Invertebrate Hormones / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009490:Neurosecretory Systems / Q000378:metabolism / Q000648:ultrastructure*; D009842:Oligopeptides / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D013997:Time Factors
chemical_list: D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; D009842:Oligopeptides; C022059:red pigment-concentrating hormone; D011188:Potassium; D011761:Pyrrolidonecarboxylic Acid