Kazuaki Oda

Correlation between the anesthetic potency of local anesthetics and their binding ability to a model membrane.

The interaction between various local anesthetics and the phospholipid membrane was examined by1H-NMR (nuclear magnetic resonance) spectroscopy. By examining the chemical shift value in order to measure the extent of proximity of various local anesthetics to the membrane, it was determined that tetracaine (10.7 Hz) was closest to the membrane, followed in descending order of proximity by dibucaine (8.8 Hz), bupivacaine (4.4 Hz), propitocaine (4.4 Hz), and lidocaine (3.5 Hz). Procaine and cocaine did not affect the chemical shift value. In addition, we studied the interaction of local anesthetics with the membrane by examining the broadening of the half-width, and determined that tetracaine (12.2 Hz) bound closest to the membrane, followed in descending order of proximity by dibucaine (11.0 Hz), bupivacaine (9.6 Hz), propitocaine (9.0 Hz), lidocaine (8.8 Hz), procaine (8.0 Hz) and cocaine (7.9 Hz). In the present study, the binding ability of local anesthetics to the phospholipid membrane was found to be directly in parallel with the potency and toxicity of the anesthetic.

Photoreaction of Benzenecarbothioamide with Aldehydes. Facile Synthesis of Tetracyclic Imidazoles.1)

Abstract Photoreaction of benzenecarbothioamide with various aldehydes in benzene solution gave 2-substituted phenanthroimidazoles.

Radioallergosorbent test (RAST) for specific IgE antibody to lidocaine, procaine and methylparaben

Although anaphylactoid reactions to local anesthetics are well known, a radioallergosorbent test (RAST) to detect specific drug reagin (IgE) anti-body has not been developed. We established RAST for local anesthetics by using carboxylic acid derivatives of lidocaine, procaine and methylparaben. Serum samples were taken from 100 volunteers who were regarded to be nonallergic to the drugs used. Negative RAST values obtained from these volunteers were 1653 ± 254(SD) cpm (lidocaine), 2750 ± 264 cpm (procaine), and 2805 ± 336 cpm (methyl paraben).