STRUCTURAL AND FUNCTIONAL CHANGES IN ORGANS AND CELLS OF THE IMMUNE SYSTEM IN SOLANUM GLAUCOPHYLLUM INTOXICATED HEIFERS

PAULA FONTANA, EDUARDO GIMENO; GRACIELA LAGUENS; CLAUDIO BARBEITO; WANDA DE GIROLAMO; ENRIQUE COSTA; SILVIA CORONATO; ENRIQUE PORTIANSKY

Utah. USA

Congreso; 7 h International Symposium on Poisonous Plant; 2005

International society of Poisonous plants

The bovine enzootic calcinosis is an intoxication caused by the chronic ingestion of a variety of calcinogenic plants like Solanum glaucophyllum (Sg). The toxic principle is a glicoside of 1,25-dihydroxyvitamin D3. The effects of vitamin D are not only important in calcium homeostasis, but also in immune regulation, cell growth, and cell differentiation. The goal of the present work was to experimentally evaluate the existence of histological and functional modifications of organs and cells of the immune system of Sg intoxicated heifers. Two years-old Aberdeen Angus heifers received two weekly doses of 25 g of Sg leaves powder during 15, 30 or 60 days (experimental group). A group was intoxicated during 15 days but sacrificed at 60 days pi (recovery group). Control animals were sacrificed at 0 and 60 days of the beginning of the experiment. Peritoneal macrophages were isolated to perform phagocytosis tests. Cells of the subiliac lymph node were isolated for immunodetection of dendrític cells using anti S-100 protein monoclonal antibodies. Samples of thymus, spleen, subiliac and superficial cervical lymph nodes were included in paraffin and histochemically (HE, lectins) and immunohistochemically (anti-S100 protein) evaluated. Tissue sections were incubated with the following biotinylated lectins: ConA, UEA1, RCA1, SBA, WGA, DBA and PNA. The stain intensity was ranked from 0 (negative) up to 3 (highly positive). Morphometric analysis was carried out on all processed sections and isolated cells. The phagocytic activity of the peritoneal macrophages was progressively reduced in the intoxicated animals with time. A significant decrease in the number of dendritic cells was observed either in isolated and lymph node. Lectinhistochemical studies revealed that binding to the lectin PNA showed the greatest differences between groups. In this sense It was correlated the reduction of cortical thymocytes binding to PNA to the progressive decrease of the cortical thymic area with intoxication time. PNA also bound to T dependent areas in spleen and lymph nodes, and with cells at the inner part of the germinal centers. This reactivity also decreased with intoxication time. Recovery group animals showed similar results than those observed in control heifers. The results of the present work demonstrate that the intoxication with Sg induces structural and functional alterations of the immune system and related cells