Proceedings of The Physiological Society

Puerto de la Cruz, Tenerife (2003) J Physiol 548P, P173

Poster Communications

Tryptophan and the innate immune response

J. Cubero, A.B. Rodríguez, J.M. Marchena, E. Ortega, J. Durán* and C. Barriga

Department of Physiology, Faculty of Sciences, University of Extremadura, 06071 Badajoz, Spain and *Hospital Infanta Cristina-Materno Infantil, Badajoz, Spain

The immune system function has a circadian rhythm. Exogenous administration of the amino acid tryptophan increases the release of the neurohormone melatonin (Hajak et al. 1991). This pineal hormone increases phagocytosis and decreases oxidative stress (Rodríguez et al. 2002). The purpose of the present work was to evaluate the ingestion capacity and oxidative metabolism in heterophils from ring dove (Streptopelia roseogrisea) after 7 days administration of 125 mg L-tryptophan (kg b.w.)-1.

The birds (n = 15) were maintained under a 12 h light (3000 lux)-12 h dark cycle and handled according to the guidelines of European Community Council Directives 86/6091 EEC. Tryptophan was administrated at 19.00 h (1 h before darkness). Phagocytosis and superoxide anion levels were measured in heterophils (isolated by a density gradient with Ficoll) at 21.00 h (2 h after administration of the amino acid) and at 02.00 h, using MIF plates and the NBT reduction test respectively. All experiments were carried out according to the guidelines of the European Community Council Directive 89/6091 EEC. Data are expressed as mean values ± S.E.M. and were compared by Student's unpaired t test. Values of P

Where applicable, experiments conform with Society ethical requirements