Histamine (HIS), a biogenic amine, is a neurotransmitter in neurons and sensory receptors in invertebrates. HIS has rarely been reported in bivalves. Our physiology work show it involved in sensory reception in sensory‐motor integration of gill lateral cell cilia in the bivalve Mollusc, Crassostrea virginica. We hypothesize HIS is present in ganglia and tissues of C. virginica. We used HPLC to measure HIS in cerebral and visceral ganglia, and peripheral tissues using a Phenomenex Gemini 5µ C18 column, Beckman HPLC system and Jasco FP 2020 Spectrofluorometer. The mobile phase was 40/60 v/v acetonitrile/phosphate buffer (50 mM, pH 6.8, 2 ml/min flow rate). Tissues were dissected, blotted dry, weighed and homogenized on ice with a Brinkman Polytron in 0.4 M HCl. Homogenates were centrifuged (4̊C, 600g, 15 min), then recentrifugation (12,000g, 15 min). Supernatants were filtered through 0.24µ filters, adjusted to pH 9.5 with NaOH, derivatized for 15 min with borate buffer (0.3 ml, pH 9.5) KCN (0.3 ml, 20 mM) and NDA (2,3‐naphthalene‐dicarboxaldehyde, 0.3 mM in methanol), injected into the HPLC and fluorescence measured (450 nM ex, 484 nM em). Results show HIS present in ng amounts in cerebral and visceral ganglia, and peripheral tissues. The study confirms HIS in the nervous system and innervated organs, including sensory tissue, and coupled with our other work shows HIS to be an endogenous biogenic amine in C. virginica.
Grant Funding Source: NIH‐ 2R25GM0600309, NSF‐ 0622197, NYSESD‐ 0516041071