Meeting Abstract
P1.133 Sunday, Jan. 4 Effects of p-Aminosalicylic Acid on the Neurotoxic Effects of Manganese on the Dopaminergic Innervation of the Gill of the Bivalve Mollusc, Crassostrea virginica NELSON, M.*; CARROLL, M.A.; CATAPANE, E.J.; Medgar Evers College therealmaestro@aol.com
Lateral cilia of the gill of Crassostrea virginicaare controlled by a reciprocal serotonergic-dopaminergic innervation from their ganglia. Serotonin is an excitatory neurotransmitter at the ganglia and gill, causing cilio-excitation. Dopamine is an excitatory neurotransmitter in the ganglia, but an inhibitory neurotransmitter at the gill, causing cilio-inhibition. Manganese (Mn) is a neurotoxin causing Manganism in people chronically exposed to elevated levels in their environment. Clinical interventions for Manganism have not been successful. Recently, p-aminosalicylic acid (PAS) is providing effective treatment of severe Manganism in humans. PAS has anti-inflammatory and chelating properties. The mechanism of action is unknown and further studies of PAS in the treatment of Manganese is necessary. Previously, we showed short-term treatments of C. virginica with Mn disrupts the dopaminergic innervation of the gill. In this study we examined acute effects of PAS, EDTA and the anti-inflammatory agent, salicylic acid (SA) on the effects of Mn on gill innervation. Beating rates of lateral cilia in gill epithelial cells were measured by stroboscopic microscopy of gill preparations which had the ipsilateral visceral ganglia (VG) attached. The cerebrovisceral connective innervating the VG were stimulated using suction electrodes, before and after additions of PAS, EDTA and SA to the gill. PAS and EDTA effectively blocked the neurotoxic effects of Mn, while SA did not. The study demonstrates that the mechanism of action of PAS in alleviating Manganism in humans may be more related to its chelating abilities as opposed to its anti-inflammatory actions. This work was supported in part by grants 2R25GM06003-05 of the Bridge Program of NIGMS, 0516041071 of NYSDOE, and 0622197 of the DUE Program of NSF.
