In vivo and in vitro studies were carried out to examine the putative hypotensive actions of S-petasin, a sesquiterpene extracted from the medicinal plant Petasites formosanus. Intravenous S-petasin (0.1-1.5 mg/kg) in anesthetized rats produced a dose-dependent hypotensive effect. In isolated aortic ring, isometric contraction elicited by KCl or the L-type Ca2+ channel agonist Bay K 8644 was re...

Migraine is a frequent and often disabling disease. Treatment is unsatisfactory in many patients. A disturbed dynamic balance between excitatory and inhibitory signal processing with enhanced cortical activity probably underlies common forms of migraine. Presynaptic voltage-gated Ca(2+) channels are critical determinants of neurotransmitter release and also contribute to trigeminovascular signa...

The Coppermine River in western Nunavut is one of Canada's great Arctic rivers, yet its vascular plant flora is poorly known. Here, we report the results of a floristic inventory of the lower Coppermine River valley and vicinity, including Kugluk (Bloody Falls) Territorial Park and the hamlet of Kugluktuk. The study area is approximately 1,200 km2, extending from the forest-tundra south of the ...

Host shifts by herbivorous insects have contributed substantially to current patterns of association between insects and plants. Despite their evolutionary and agricultural interest, however, the plant traits that predispose insects to colonize some plants instead of others are poorly understood. To examine whether ancestral and novel hosts share similar chemical oviposition stimulants that wou...

The genus Clerodendrum L. (Family: Lamiaceae) is very widely distributed in tropical and subtropical regions of the world. More than five hundred species of the genus are identified till now, which includes small trees, shrubs and herbs. Ethno-medical importance of various species of Clerodendrum genus has been reported in various indigenous systems of medicines and as folk medicines. The genus...