TNF and cardiac hypertrophy: ISO infusion at a low dose (e.g., 12.5 μg/kg/h) that is capable of inducing cardiac hypertrophy but not fibrosis was shown to rapidly upregulate the gene expression of TNF and other inflammatory cytokines including interleukin (IL)-1β, IL-6, inducible nitric oxide synthase, and monocyte chemotactic protein-1 (MCP-1) in a TNFR1-dependent manner (64).