Which mechanisms are involved in taurine-dependent granulocytic immune response or amino- and alpha-keto acid homeostasis?
We examined the effects of beta-alanine (taurine analogue and taurine transport antagonist), taurine (regarding its role in neutrophil (PMN) immunonutrition) and taurine combined either with L-NAME (inhibitor of *NO-synthase), SNAP (*NO donor), DON (glutamine-analogue and inhibitor of glutamine-requiring enzymes), DFMO (inhibitor of ornithine-decarboxylase) and beta-alanine on neutrophil amino- and alpha-keto acid profiles or important PMN immune functions in order to establish whether taurine transport-, nitric oxide-, glutamine- or ornithine-dependent mechanisms are involved in any of the taurine-induced effects. According to the present findings, the taurine-mediated effect appears to be based primarily on a modulation of important transmembraneous transport mechanisms and only secondarily on directly or indirectly induced modifications in intragranulocytic amino- and alpha-keto acid homoeostasis or metabolism. Although a direct relation to the parallel observed immunological modifications can only be presumed, these results show very clearly that compositional modifications in the free intragranulocytic amino- and alpha keto-acid pools coinciding with changes in intragranulocytic taurine levels are relevant metabolic determinants that can significantly influence the magnitude and quality of the granulocytic immune response.
Mühling
J
J
Clinics of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Giessen and Marburg, Justus-Liebig-University Giessen, Giessen, Federal Republic of Germany. joerg.muehling@chiru.med.uni-giessen.de
Nickolaus
K A
KA
Matejec
R
R
Langefeld
T W
TW
Harbach
H
H
Engel
J
J
Wolff
M
M
Weismüller
K
K
Fuchs
M
M
Welters
I D
ID
Krüll
M
M
Heidt
M C
MC
Hempelmann
G
G
D000328:Adult; D000596:Amino Acids / Q000378:metabolism*; D003980:Diazooxonorleucine / Q000494:pharmacology; D000518:Eflornithine / Q000494:pharmacology; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007651:Keto Acids / Q000378:metabolism*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009504:Neutrophils / Q000276:immunology / Q000502:physiology*; D009195:Peroxidase / Q000378:metabolism; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism; D013654:Taurine / Q000502:physiology*; D015091:beta-Alanine / Q000494:pharmacology*
D000596:Amino Acids; D007651:Keto Acids; D003980:Diazooxonorleucine; D013481:Superoxides; D015091:beta-Alanine; D013654:Taurine; D026423:S-Nitroso-N-Acetylpenicillamine; D006861:Hydrogen Peroxide; D009195:Peroxidase; D019331:NG-Nitroarginine Methyl Ester; D000518:Eflornithine