Clinical and experimental pharmacology & physiology
-
Clin. Exp. Pharmacol. Physiol. · Jul 2005
Comparative StudyEffects of tail fat on halothane biotransformation in fat-tailed sheep.
1. The aim of the present study was to evaluate the effects of tail fat on halothane biotransformation following similar anaesthetic exposure in intact sheep and sheep with a ligated median sacral artery. 2. A prospective randomized experimental study was performed using 12 healthy, 10-12-month-old female sheep. 3. ⋯ Extubation and sternal recumbency times were significantly longer in intact sheep. 5. Ligation of the MSA in fat-tailed sheep induced a significant reduction in SFC, suggesting that the presence of tail fat substantially affects halothane metabolism during the peri-anaesthetic period in sheep. The greater extent of halothane biotransformation may be clinically important in, otherwise normal, obese patients.
-
Clin. Exp. Pharmacol. Physiol. · Jul 2005
Clinical TrialWagner-Nelson method for analysing the atypical double-peaked [13CO2] excretion curve in the [13C]-octanoate gastric emptying breath test in humans.
1. In the [(13)C]-octanoic acid breath test, the time versus pulmonary [(13)CO(2)] excretion rate curve is analysed using mathematical curve-fitting techniques to calculate gastric emptying parameters. Thus, the goodness-of-fit highly influences the accuracy of the breath test. ⋯ Wagner-Nelson analysis applied to the breath test described precisely the characteristic emptying pattern of the two emptying phases being interrupted by the plateau phase. Conventional analysis for the breath test failed to detect the plateau phase. 4. The Wagner-Nelson method is a useful tool for analysing atypical double-peaking [(13)CO(2)] excretion curves.
-
Clin. Exp. Pharmacol. Physiol. · Jul 2005
Involvement of N-methyl-D-aspartate receptors and nitric oxide in the rostral ventromedial medulla in modulating morphine pain-inhibitory signals from the periaqueductal grey matter in rats.
1. Supraspinal opioid antinociception is mediated, in part, by connections between the periaqueductal grey (PAG) and the rostral ventromedial medulla (RVM). Morphine antinociception from the PAG is decreased by serotonin, N-methyl-d-aspartate (NMDA) and opioid receptor antagonists administered into the RVM. ⋯ Mesencephalic morphine antinociception was significantly reduced after pretreatment with l-NAME (0.6-1.3 micromol) or MK-801 (0.8 nmol). The reduction in mesencephalic morphine antinociception when MK-801 (0.8 nmol) and l-NAME (1 micromol) were microinjected sequentially into the RVM was not significantly different from the effects of MK-801 (0.8 nmol) or l-NAME (1 micromol) administered alone. 4. These data imply that NMDA receptors and nitric oxide production in the RVM modulate the transmission of opioid pain-inhibitory signals from the PAG.
-
Clin. Exp. Pharmacol. Physiol. · Jan 2005
Effects of post-treatment with low-dose propofol on inflammatory responses to lipopolysaccharide-induced shock in conscious rats.
1. In the present study, we used a low dose of propofol (5 mg/kg per h) to investigate its effects on the pro-inflammatory cytokines (tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-10) and changes in nitric oxide (NO) following lipopolysaccharide (LPS) for a period of 12 h in conscious rats. 2. Experiments were designed to induce endotoxin shock by intravenous injection of Klebsiella pneumoniae LPS (10 mg/kg) in conscious rats. ⋯ Lipopolysaccharide also caused a decrease in the white blood cell count and haematocrit. 5. Post-treatment with propofol slightly, but not significantly, affected the LPS-induced systemic hypotension, tachycardia, leukocytopenia and anaemia. 6. These findings suggest that low-dose propofol may be beneficial to the inflammatory change in sepsis.