title: Lymphopenic effects on mice of a component of ammonia caramel, 2-acetyl-4(5)-tetrahydroxybutylimidazole (THI).
abstract: A derivative of ammonia caramel colour (AC) is known to induce a selective lymphopenia in rats. Accordingly, the haematological effects were studied in mice of oral administration in drinking water of 2-acetyl-4(5)-tetrahydroxybutylimidazole (THI), the component of AC responsible for lymphopenia. Initially five groups of BALB/c mice (five mice per group) were given doses of THI ranging from 0 to 200 parts/10(6) and bled weekly. Doses of THI from 5 to 100 parts/10(6) had no effect on circulating leucocytes over 6 weeks, but lymphopenia occurred with 200 parts/10(6). An increase in the concentration of THI to 400 parts/10(6) in the group on the lowest dose resulted in lymphopenia. An increase in dosage in two groups of mice, to 1000 and 2000 parts/10(6), resulted in marked lymphopenia. The number of neutrophils, eosinophils and monocytes remained unchanged throughout the experiment. Measurement of the proportions of CD4(L3T4)+ and CD8(Ly2)+ lymphocytes in lymph nodes from mice on high doses of THI did not show a selective depression of either subset, although both were increased relative to non-T cells. THI causes a selective lymphopenia in mice, as in rats, but at relatively higher doses, and merits investigation in mice as an experimental treatment for states of lymphocyte excess or overactivity.
authors.affiliation: Clinical Research Unit, Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.
authors.forename: A
authors.initials: A
authors.lastname: Iscaro
authors.forename: I R
authors.initials: IR
authors.lastname: Mackay
authors.forename: C
authors.initials: C
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D002182:Candy; D002241:Carbohydrates; D004305:Dose-Response Relationship, Drug; D005505:Food Coloring Agents / Q000008:administration & dosage / Q000633:toxicity*; D007093:Imidazoles / Q000008:administration & dosage / Q000633:toxicity*; D007958:Leukocyte Count; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D008231:Lymphopenia / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009930:Organic Chemicals; D013601:T-Lymphocytes / Q000145:classification / Q000187:drug effects / Q000276:immunology; D013997:Time Factors
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D002241:Carbohydrates; D005505:Food Coloring Agents; D007093:Imidazoles; D009930:Organic Chemicals; C569050:caramel coloring; C049929:2-acetyl-4(5)-tetrahydroxybutylimidazole