Meeting Abstract

P1.182  Friday, Jan. 4  Effects of Antioxidants and Anti-inflammatory Agents on Neurotoxic Effects of Manganese on Dopaminergic Innervation of Gill of the Bivalve Mollusc Crassostrea virginica LAFLEUR, K.*; ROTIBI, M.; CATAPANE, E.J.; CARROLL, M.A.; Medgar Evers College; Medgar Evers College; Medgar Evers College; Medgar Evers College catapane@mec.cuny.edu

Lateral cilia of the gill of Crassostrea virginica are controlled by a serotonergic-dopaminergic innervation. Dopamine acts as an excitatory neurotransmitter within the ganglia, but an inhibitory neurotransmitter at gill, causing cilio-inhibition. The mechanism of action of manganese toxicity is not fully understood, but may be due to oxidative damage. We found several chelators, including p-aminosalicylic acid (PAS) prevented neurotoxic effects of Mn in C. virginica. The therapeutic actions of PAS are thought to be due to chelation, but PAS is also anti-inflammatory. We sought to determine if anti-inflammatory agents and/or antioxidants are effective in preventing neurotoxic actions of Mn in gill of C. virginica. Indomethacin (IM), an anti-inflammatory agent with antioxidant abilities, and ascorbic acid (AA), an antioxidant with possible anti-inflammation abilities were tested. We examined acute and short term (3 – 5 days) treatment of IM and AA on Mn toxicity on dopaminergic innervation. Beating rates of lateral cilia in gill epithelial cells were measured by stroboscopic microscopy. Acute or short-term treatments of IM or AA (25 – 100 μM) and had no effect on the cilio-inhibitory effects of dopamine (10^-6 – 10^-3 M). When acute or short-term Mn treated animals (25 – 100 μM) were pretreated with IM or AA (25 – 100 μM), both drugs effectively prevented the neurotoxic effects of Mn, with AA being more effective than IM. The study demonstrates antioxidants and anti-inflammatory agents can block the neurotoxic actions of Mn and may be possible therapeutic agents in the treatment of Manganism.