- Interleukin 1 beta markedly stimulates nitric oxide formation in the absence of other cytokines or lipopolysaccharide in primary cultured rat hepatocytes but not in Kupffer cells. Kitade, H., Sakitani, K., Inoue, K., Masu, Y., Kawada, N., Hiramatsu, Y., Kamiyama, Y., Okumura, T., Ito, S. Hepatology (1996)