In Vitro Induction of Aryl Hydrocarbon Hydroxylase in Baboon Pulmonary Alveolar Macrophages and Peripheral Blood Lymphocytes

Abstract

Aryl hydrocarbon hydroxylase (AHH) activity was measured in cultured pulmonary alveolar macrophages (PAMs) (n = 12) and peripheral blood lymphocytes (n = 72) from unrelated baboons. It was determined that optional AHH induction was observed in PAMs when cells were cultured for 24 or 48 hours in the presence of a 15 μM concentration of the inducer, benzanthracene (BA). Maximal enzyme activity was observed in mitogen-activated lymphocytes when cells were cultured for 96 or 120 hours in the presence of 10 μM BA concentration. Additionally, there were no differences in PAM or lymphocyte AHH induction when cells were cultured in different types of culture medium (P > 0.10 in all instances, using paired, 2-tailed, Student's t-test). Similarly, no differences were observed between PAM AHH activity when human AB serum or autologous baboon serum was used in the culture medium (P > 0.30). However, slightly higher BA-induced AHH levels were noted in lymphocytes cultured in the presence of autologous baboon serum as compared with human AB serum (P < 0.02). Using optimal culture conditions for PAMs and lymphocytes from individual baboons a 6.5-fold interindividual variation in PAM and a 30-fold variation in lymphocyte BA-induced AHH levels were observed (n = 8 and 64, respectively). These studies document that AHH is measurable in cultured baboon PAMs and lymphocytes and that there is wide interindividual variation in BA-induced AHH levels. The distribution of AHH activity appears to be similar to that observed in the human population.