Identification and quantitative measurements of biogenic amines and DOPA in the central nervous system and haemolymph of the crayfish Pacif ast acus leniusculus (crustacea)

Role of biogenic amines and cHH in the crustacean hyperglycemic stress response

“…The circulating basal level of 5-HT in P. elegans was 4.81±0.98·ng·ml -1 , which is higher than that found by Sneddon et al (2000) in C. maenas, where the basal level of 5-HT in the hemolymph was ~1·ng·ml -1 , and different from those found in the crayfish Pacifastacus leniusculus (Elofsson et al, 1982).…”

“…The release of cHH from the eyestalk reached the maximum after 2·h of exposure, and in the hemolymph the maximum peak of circulating cHH was reached after 2·h of exposure. The release of 5-HT from the eyestalk (Elofsson et al, 1982;Kulkarni and Fingerman, 1992) into the hemolymph after stress precedes the release of cHH, confirming its role as a neurotransmitter acting on cHH neuroendocrine cells (Saenz et al, 1997;Garcia and Aréchiga, 1998;Escamilla-Chimal et al, 2002). The fact that copper induces the rapid and massive release of 5-HT from the eyestalk explains its demonstrated role in inducing the release of cHH (Lorenzon et al, 2004b) and the consequent hyperglycemia in intact but not in eyestalkless animals (Lorenzon et al, 2000).…”

“…Biogenic amines and enkephalin have been found to mediate the release of several neurohormones from crustacean neuroendocrine tissues. Serotonin (5-HT; 5-hydroxytryptamine) is well known as a neurotransmitter in crustaceans on several grounds, and its levels have been measured in the nervous system and hemolymph of various crustacean species (Elofsson et al, 1982;Laxmyr, 1984;Kulkarni and Fingerman, 1992), thus suggesting a possible role as a neurohormone (Rodrigues-Soza et al, 1997). Serotonin has long been known to have a potent hyperglycemic effect in several crustacean species (Bauchau and Mengeot, 1966;Keller and Beyer, 1968;Lee et al, 2000;Lorenzon et al, 1999Lorenzon et al, , 2004aSantos et al, 2001).…”

Acetylcholine in the crayfish optic lobe: concentration profile and cellular localization

“…The earliest studies used a variety of methods such as formaldehyde-induced fluorescence for catecholamines (Elofsson and Klemm, 1972;Elofsson et al, 1977), alpha-bungarotoxin binding for ACh receptors (Schmidt-Nielsen et al, 1977;Maxwell and Hildebrand, 198 1) and the incorporation of radioactive precursors (CamposOrtega, 1974;Maxwell and Hildebrand, 198 1;Elias and Evans, 1984). Quantitative assays have been based upon neurotransmitter extraction from optic lobe fragments and analysis by electrophoresis and high-performance liquid chromatography (Maxwell et al, 1978;Maxwell and Hildebrand, 198 1;Elofsson et al, 1982;Elias and Evans, 1983;Garcia and Arechiga, 1986). These studies indicate that the optic lobe contains significant quantities of ACh, GABA, octopamine, dopamine, serotonin, and histamine.…”

Altered dopamine levels induced by the parasite Profilicollis antarcticus on its intermediate host, the crab Hemigrapsus crenulatus

“…Estimations made with HPLC ED (electrochemical detection) indicate the absence of circulating dopamine and the predominance of octopamine (2.2 ng /ml) in the crayfish Pacifastacus lenusculus (Elofsson et al, 1982). Furthermore, in a euryhaline crab (Eriocheir sinensis) dopamine concentrations were 0.0022 pg/ml 0.0017, with a maximum increase of 460% under conditions of ionic stress (Péquéux et al, 2002).…”