Gossypol stimulates opening of a Ca2+‐ and Na+‐permeable but Ni2+‐ and Co2+‐impermeable pore in bEND.3 endothelial cells

Gossypol, a polyphenolic dialdehyde toxin isolated from cotton seed, has anti‐cancer properties and has recently shown some success in the treatment of glioma. Its effects on brain neurons and blood vessels are poorly understood. In this work we examined the effects of gossypol on cytosolic Ca²⁺ concentration ([Ca²⁺]_i) of mouse brain bEND.3 endothelial cells. Cell viability tests revealed that after 3 hour and 18 hour exposures, 10 µmol/L gossypol caused 23% and 65% cell death, respectively; 3 µmol/L gossypol caused no and 21% cell death, respectively. [Ca²⁺]_i was raised concentration‐dependently by 1‐10 µmol/L gossypol. We then explored the Ca²⁺ signalling triggered by 3 µmol/L gossypol, which inflicted minimal toxicity: the Ca²⁺ signal was composed largely of Ca²⁺ influx and to a small extent, intracellular Ca²⁺ release. Such Ca²⁺ influx was much larger than store‐operated Ca²⁺ influx triggered by maximal Ca²⁺ pool depletion. The Ca²⁺ influx triggered by 3 and 10 µmol/L gossypol caused NO release and cell death, respectively. Gossypol also triggered influx of Mn²⁺ and Na⁺, but not Ni²⁺ and Co²⁺. Gossypol‐triggered Ca²⁺ signal was inhibited only by 14% and 37% by 100 µmol/L La³⁺ and 10 µmol/L nimodipine, respectively; and not suppressed at all by 5 mmol/L Ni²⁺. Gossypol‐triggered Ca²⁺ signal was suppressed by 78% by 30 µmol/L ruthenium red, suggesting gossypol may act on TRPV channels. Our results suggest gossypol triggered opening of a non‐selective cation pore, possibly a member of the TRPV family.     

Surveillance of drug abuse in Hong Kong by hair analysis using LC‐MS/MS

The aim of this study is to reveal the habits of drug abusers in hair samples from drug rehabilitation units in Hong Kong. With the application of liquid chromatography–tandem mass spectrometry (LC–MS/MS) technology, a total of 1771 hair samples were analyzed during the period of hair testing service (January 2012 to March 2016) provided to 14 drug rehabilitation units including non‐governmental organizations (NGOs), rehabilitation centers, and medical clinics. Hair samples were analyzed for abused drugs and their metabolites simultaneously, including ketamine, norketamine, cocaine, benzoylecgonine, cocaethylene, norcocaine, codeine, MDMA, MDA, MDEA, amphetamine, methamphetamine, morphine, 6‐acetylmorphine, phencyclidine, and methadone. The results showed that ketamine (77.2%), cocaine (21.3%), and methamphetamine (16.5%) were the frequently detected drugs among those drug abusers, which is consistent with the reported data. In addition, the usage of multiple drugs was also observed in the hair samples. About 29% of drug‐positive samples were detected with multiple drug use. Our studies prove that our locally developed hair drug‐testing method and service can be a valid tool to monitor the use of abused drugs, and which could facilitate rehabilitation program management.