Variation in pentobarbitone sleeping time in mice 2. Variables affecting test results

Abstract

SummaryThe effect of some environmental factors on the pentobarbitone sleeping time (PST) in inbred strains of mice has been investigated.Age, dose level and fasting before the test significantly altered the PST while the source of the drug and regular handling of the mice had no elTect. None of these factors affected strains differentially.Unsystematic effects such as litter differences contributed only a small proportion of the total variation in the experiments.The strain rankings were different from those obtained in some previous experiments.The effects of some of the environmental factors on the PST did not always agree with previous work. The implications of these results for the design of similar experiments and the relevance of baseline values in laboratory animals are discussed.

Variation in barbiturate sleeping time in mice 3. Strain × environment interactions

“…There was no effect of variation in bodyweight on PST in a group of age-matched mice in an earlier study (Lovell, 1986b) (Lovell, 1979).…”

“…The method described earlier (Lovell, 1986a(Lovell, , 1986b was used. All mice were injected with 60 mg/kg pentobarbitone sodium (Nembutal Abbot Laboratories, Queenborough, Kent).…”

“…PST was also affected by factors such as the age of the animal and the dose revel (Lovell, 1986b). These results showed that PST was a 'model' in vivo pharmacological test which could be carried out quickly and conveniently on large numbers of animals at the same time so that complex experimental designs could be used.…”

Genetic determinants of sensitivity to pentobarbital in inbred mice

“…A few similar studies with barbiturates are reviewed in Broadhurst (1978). In a series of studies, Lovell (1986aLovell ( , 1986bLovell ( , 1986c demonstrated that strain differences in PB-induced loss of righting reflex interacted with environmental variables such as ambient temperature, bedding composition and diet. However, in nearly all of the older literature, only righting reflex was tested, and drug levels were not measured, so strain differences (and their interactions) may have been pharmacokinetic in origin.…”

Moduratory effect of Thai traditional medicine (Yahom Tultavai) on hepatic cytochrome P450 enzymes and pentobarbital-induced sleeping in mice

“…The length of pentobarbital-induced sleeping time is inversely related to the rate of drug metabolism. Its duration of action can be altered by inducers or inhibitors (Lovell, 1986). Phenobarbital pre-treatment is known to shorten the sleeping time induced by pentobarbital.…”