Bile Salt Potentiation of Pharmacologic Effects and Drug Uptake in Goldfish

Abstract

Concentrations of 1 × 10−4M and 2 × 10−4M sodium taurodeoxycholate (STDC), which demonstrate no intrinsic pharmacologic activity, significantly potentiate the pharmacologic effects (i.e., time required to produce overturn) of pentobarbital and ethanol in goldfish. Quantitatively similar potentiation is noted when the fish is exposed to a bile salt-drug solution or when the fish is pretreated with STDC, rinsed, and immediately exposed to drug solution. The present results suggest that potentiation is independent of the duration of pretreatment of fish with STDC. The effects of STDC are mediated very quickly, reach a maximum level within minutes, and are slowly reversible. The results are consistent with a mechanism involving adsorption of bile salt molecules on the biologic membrane, consequent alteration of membrane permeability, and a resultant decrease in the time required to observe a pharmacologic response to ethanol and pentobarbital. A 1 × 10−4M STDC solution also increases significantly the absorption of 4-aminoantipyrine in goldfish.