1Division of Gastroenterology, Liver Unit, University Hospital Virgen Macarena, Sevilla, Spain
2Department of Pharmacology, University Hospital Virgen Macarena, Sevilla, Spain
Reprint requests and correspondence: Manuel Jiménez-Sáenz, C/Antonio Cortes Llado 6, Edificio Madeira Esc 1-2° A, Sevilla 41004, Spain.
Received 18 July 2000; accepted 24 July 2000