Forensic aspects of the metabolism and excretion of cannabinoids following oral ingestion of cannabis resin.

Following oral ingestion of cannabis resin, delta 9-THC-11-oic acid and its O-ester glucuronide were detected using RIA and combined hplc/RIA and shown to be major plasma metabolites of delta 9-THC. delta 9-THC-11-oic acid was not excreted in the urine in significant concentrations, the glucuronide conjugate being the major urinary metabolite detected. delta 9-THC metabolites were detected in blood for up to 5 days and in urine for up to 12 days following a single oral dose of delta 9-THC (20 mg). Estimates for the half life of delta 9-THC-11-oic acid and its glucuronide in plasma, and total metabolites in urine have been obtained. Interpretation of blood or urine total cannabinoid levels is most difficult, however, drug/metabolite ratios and metabolite/metabolite ratios may have potential for indicating recent cannabis use.

Cutaneous histamine-releasing activity of dimethylsulphoxide (DMSO) in guinea pigs.

Dimethylsulphoxide (DMSO) induced swelling in guinea pig ears was found to be abolished by H1- and H2-receptor blocking agents. On histological examination of the ears some degranulation of mast cells was seen. It was concluded that the swelling was mediated by histamine release.

Prolactin responses to cimetidine.

1 An intravenous injection of cimetidine 400 mg to four healthy male subjects resulted in high blood concentrations of cimetidine and a rapid three-fold increase in serum prolactin. 2 This effect was prevented by pretreatment with bromocriptine. 3 No increase in prolactin followed a single oral dose of cimetidine 800 mg administered to a different group of healthy male subjects. The mean peak blood concentration of cimetidine was less than 20% of that achieved with 400 mg i.v. 4 Only isolated reports have been received of gynaecomastia or galactorrhoea occurring during cimetidine treatment. In three of seven cases studied there was associated hyperprolactinaemia. This may be an idiosyncratic response at the lower blood concentration of cimetidine associated with oral therapeutic dose regimens.

Renin and acute renal failure: studies in man.

Plasma renin concentration was increased, usually appreciably, in 22 out of 25 patients with acute renal failure, the average value being 226 units/litre (mean for normal subjects 8.2 units/1.). The highest renin values were found in the first 10 days of the disease; lower and sometimes normal values were found subsequently. Unequivocal acute tubular necrosis was present in only two of the eight cases examined post mortem.These findings are compatible with Goormaghtigh's proposal that an excess of renin and angiotensin may act within the kidney to produce acute renal failure.