The effects of ginkgolide B (BN52021) on guinea pig vestibular nucleus neurons in vitro: importance of controlling for effects of dimethylsulphoxide (DMSO) vehicles.
The present study investigated the effects of the platelet-activating factor (PAF) receptor antagonist, ginkgolide B, on guinea pig medial vestibular nucleus (MVN) neurons in vitro and addressed the potential problem of using dimethylsulphoxide (DMSO) as a solvent. Using DMSO as a solvent, 10(-10), 10(-8) and 10(-4) M ginkgolide B had no effect on extracellularly recorded MVN neurons in brainstem slices in vitro. Using 10(-6) M ginkgolide B, 50% (5/10) of MVN neurons exhibited a decrease in firing rate and 10% (1/10) of neurons responded with an increase in firing rate. While attempting to control for possible DMSO vehicle effects, 40% (4/10) of MVN neurons displayed a decrease in firing rate when ginkgolide B (10(-6) M) was presented before the DMSO control solution. When the DMSO vehicle was presented first, only 10% (1/10) responded similarly. In some cases the DMSO vehicle alone also produced a decrease in MVN neuron firing rate. These results emphasise the importance of using adequate DMSO control conditions in ginkgolide research.
Maclennan
K
K
Department of Pharmacology, School of Medical Sciences, University of Otago Medical School, Dunedin, New Zealand.
Smith
P F
PF
Darlington
C L
CL
D000818:Animals; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004224:Diterpenes; D004305:Dose-Response Relationship, Drug; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D046934:Ginkgolides; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007783:Lactones / Q000494:pharmacology*; D014726:Vestibular Nuclei / Q000187:drug effects*
D004224:Diterpenes; D005343:Fibrinolytic Agents; D046934:Ginkgolides; D007783:Lactones; C045856:ginkgolide B; D004121:Dimethyl Sulfoxide