Abstract
The electrical excitability of nerve and muscle is due to the voltage-sensitive ion channels in the plasma membrane. Natural toxins that selectively block the voltage-sensitive channels have provided valuable information about the functional diversity of the voltage sensitive channel superfamily. Also, natural toxins have been extensively used to elucidate drug receptor functions. Reversible protein phosphorylation plays an essential role in controlling wide range of cellular events such as smooth muscle contraction, cell division, cell signalling, differentiation and metabolism. Selective inhibitors of protein kinase and phosphatase are widely used as first-choice reagents for elucidating physiological role of protein phosphorylation and dephosphorylation. The key points of the intracellular signalling cascades, including NF-κB and DNA polymerase can be found by applying a selective modulator to intact-cell preparations, where it affects a particular cellular response. From this viewpoint, a variety of physiologically active substances have been extensively studied by pharmacologists, physiologists and biochemists, because they interact with specific sites. This symposium focuses on research that has given insight into the cellular and molecular mechanisms of action of natural products isolated from marine organisms, terrestrial plants and microorganisms, and has revealed the molecular regulatory mechanisms of signal transduction through the use of these compounds. [Jpn J Physiol 54 Suppl:S12 (2004)]
