Methodology monkey

Until recently, there was little clear evidence that cannabis use was toxic to neurons. Cannabinoids have been shown to have a mix of neurotoxic and neuroprotective effects and mixed results have been found in different studies. Scallet (1991) points out significant methodological differences in the existing studies that influence their outcomes. Critical determinants of neurotoxicity are both age during exposure and duration of exposure. For example, cannabinoid administration was required for at least three months (8-10% of a rat s lifespan) to produce neurotoxic effects in peripubertal rodents. This is comparable to about three years exposure in rhesus monkeys and seven to ten years in humans. Reports of neurotoxicity in primates were inconsistent, with up to 12 months of daily exposure. Longer exposures have not yet been studied (Scallet 1991). 

Owada, E., et al. 1977. Vaginal drug absorption in rhesus monkeys. I. Development of methodology. J Pharm Sci 66 216. 

Kemnitz JW, Weindruch R, Roecker EB, Crawford K, Kaufman PL, Ershler WB. Dietary restriction of adult male rhesus monkeys Design, methodology, and preliminary findings from the first year of study. J Gerontol 1993 48 B17-B26. 

In a 28 day study in monkeys with oral administration, 19 of 78 control samples showed test item concentrations between 0.11 and 1.3 ng/ml, while in 77 of 77 samples of the low-dose group the respective concentrations ranged from 0.11 to 26.6 ng/ml (LLOQ was 0.1 ng/ml). After probing the whole procedures, the problem could be limited to the bioanalytical methodology In the course of the study changes were effected that had resulted in better sensitivity, i.e. in a reduction of the LLOQ from 0.3 ng/ml to 0.1 ng/ml, with the additional effect, however, that carry-over effects which had not been detected in the validation became observable for the study samples, explaining these findings. 

Percutaneous absorption mechanisms - methodology - drug delivery. Marcel Dekker, New York, pp 335-342 Wester RC, Noonan PK, Cole MP, Maibach HI (1977) Percutaneous absorption of testosterone in the newborn rhesus monkey comparison to the adult. Pediatr Res ii 737-739 Yeung D, Kantor S, Nacht S, Cans EH (1983) Percutaneous absorption, blood levels, and urinary excretion of resorcinol applied topically in humans. Int J Dermatol 22 321-324 Young E (i960) Ammoniated mercury poisoning. Br J Dermatol... 

We have found the monkey to be an extremely useful animal model with which to explore the effects of lead (as well as other neurotoxic agents) on the developing organism. The use of sophisticated behavioural methodology has allowed detection of clear, dose-related deficits as a result of lead exposure on tests of activity, attention and memory, distractibility and adaptability. In... 

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