Chemical Reagents

The major cell-permeable diterpene isolated from the Indian plant Coleus forskohlii. At low doses, it acts as a positive inotropic agent. At higher doses, it serves as a hypotensive and vasodilatory agent due to its actions as a smooth muscle relaxant. No major side effects are observed at effective doses. Forskolins pharmacological activities are due to its activation of adenylate cyclase (EC₅₀ = 4 ?M), resulting in increased cAMP levels. The exact mechanism of forskolins positive inotropic effect is unknown but may be related to a cAMP-dependent increase in Na⁺ permeability that results in indirect augmentation of Ca²⁺ release. Inhibits MAP kinase in rat renal mesangial cells (IC₅₀ = 25 ?M). Also acts as a Hh pathway antagonist. Shown to inhibit apoptosis in cerebellar granule cells and to induce apoptosis in resting human B lymphocytes.