title: Tetramethylpyrazine, a calcium antagonist.
abstract: Tetramethylpyrazine (TMP) is a compound purified from a medicinal plant Ligusticum wallichii Franch. Its effects on in vivo blood pressure, in vitro vascular contractility, and intracellular calcium regulation in rats were examined in the present study to see if it was a possible calcium antagonist in the vascular tissue. Data showed that TMP was hypotensive and had a direct vascular effect. It not only blocked the entry of extracellular calcium through calcium channels but also inhibited the release of intracellular stored calcium in the vascular smooth muscle cell. It was a true calcium antagonist.
authors.affiliation: Department of Physiology, University of Alberta, Edmonton, Canada.
authors.forename: P K
authors.initials: PK
authors.lastname: Pang
authors.forename: J J
authors.initials: JJ
authors.lastname: Shan
authors.forename: K W
authors.initials: KW
authors.lastname: Chiu
mesh_terms: D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D010946:Plants, Medicinal; D011719:Pyrazines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D002121:Calcium Channel Blockers; D011719:Pyrazines; D002118:Calcium; C017953:tetramethylpyrazine