Abstract
To investigate an interaction between lymphocytes and adrenal medullary cells, we examined the effect of bovine lymphocytes or their conditioned medium on catecholamine efflux from bovine adrenal medullary cells. 1) Co-culture of adrenal medullary cells with lymphocytes caused an increase in catecholamine efflux from the cells. 2) Treatment of adrenal medullary cells with the conditioned media prepared from lymphocytes also increased the efflux of catecholamines. 3) Heat treatment of the conditioned media by boiling for 10 min reduced the stimulatory effect to 12 % of control. The stimulatory effect of the factor still remained even after dialysis using a < 8kDa MW cutoff tube. 4) The lymphocyte-derived factor was partially purified from conditioned media using a DEAE-cellulose ion exchange column. Three peaks of the active fraction were collected and pooled. Two antisera against the peak 1 and peak 2 were prepared and named as fuzzy antibody 1 and fuzzy antibody 2. Using the fuzzy antibody 1, 20 positive clones were isolated from bovine spleen cDNA library and partially sequenced. The present findings suggest that lymphocytes secrete factors which stimulate catecholamine efflux from adrenal medullary cells. The lymphocyte-derived factor(s) which seems to be heat-sensitive and have molecular mass of more than 8kDa will be cloned.
