Gender Differences in Pulmonary Inflammation Following Systemic Cadmium Administration in Rats

Objective To examine the presence of gender differences in pulmonary inflammation evoked by acute systemic cadmium administration in rats. Methods Presence of basic indicators of lung inflammation (inflammatory cytokine lung content, leukocyte infiltration and activity of cells recovered from lungs by enzyme digestion) was analyzed and compared in animals of the two sexes. Results Intraperitoneal administration of cadmium (1.0 mg/kg) resulted in higher cadmium content in lungs of female rats. Higher tumor necrosis factor (TNF) content was noted in lung homogenates of male rats, while interleukin-6 (IL-6) content was slightly, but signifaicantly greater in lungs of female rats. Increased leukocyte infiltration was observed in lungs of male rats, mainly due to neutrophils. Increased responsiveness to phorbol myristate acetate (PMA) stimulation was noted in cells recovered from lungs of male rats. Rise in intracellular content of myeloperoxidase (MPO) was noted in lung cells from cadmium-treated rats of both sexes, but higher in cells from male rats. Conclusion Presented data documented a more intense pulmonary inflammatory response to systemic cadmium administration in males, with higher IL-6 levels in lungs of female individuals. These sex differences in proinflamatory activity of cadmium in lungs should be taken into consideration in studying the remote toxicity of this heavy metal.