Interleukin-1 beta stimulates growth of adrenocortical cells in primary culture

Using tritiated-thymidine incorporation as a measure of cell growth, interleukin-1 beta stimulated the growth of bovine zona fasciculata/reticularis adrenocortical cells after 72 h in primary culture. Within the range of 10-1000 pg/ml, interleukin-1 beta produced over 40% of angiotensin II-stimulated [3H]thymidine incorporation (P less than 0.005 compared with basal for 10 pg/ml and 1000 pg/ml; P less than 0.05 for 100 pg/ml; two-tailed unpaired Student's t-test). Interleukin-1 beta did not directly stimulate cortisol secretion. By stimulating adrenocortical growth, the increase in interleukin-1 during fever provides a potential mechanism for chronically raising glucocorticoid output. This study is the first demonstration of a long-term effect involving interleukin-1 beta on the adrenal cortex.