J Am Assoc Lab Anim
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J Am Assoc Lab Anim · Sep 2006
Acetaminophen self-administered in the drinking water increases the pain threshold of rats (Rattus norvegicus).
Previous studies have suggested that the addition of flavored acetaminophen suspension (for example, Children's Tylenol) in the drinking water of rats may not be effective in producing postoperative analgesia because of low levels of consumption. However, these investigations neither measured analgesia nor compared the consumption by rats that had undergone surgery with that by unmanipulated rats. ⋯ Moreover, rats that had undergone surgery drank significantly more acetaminophen solution than did those that had no surgery. These data suggest that oral self-administration of flavored acetaminophen by rats may be an appropriate means to reduce pain.
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J Am Assoc Lab Anim · May 2006
Comparative Study Clinical TrialComparison of the stress response in rats to repeated isoflurane or CO2:O2 anesthesia used for restraint during serial blood collection via the jugular vein.
The primary objective of this study was to compare the effect of 2 commonly used anesthetics, isoflurane and CO2, on the physiologic stress hormone, corticosterone, in rats during serial blood collections. Circulating corticosterone concentrations were monitored during serial jugular blood sampling in rats exposed to either isoflurane or CO2 anesthesia. Blood was drawn under anesthesia at 6 time points (initial sampling and 0.5, 1, 2, 3, and 24 h after initial sampling) across a 24-h period. ⋯ However, the increase in corticosterone at subsequent time points was significantly higher for animals exposed to CO2, suggesting that the cumulative effects of repeated exposure to stressful stimuli was more evident for this type of anesthesia. The apparent reduction in stress effects of isoflurane as opposed to CO2, coupled with other published adverse effects of CO2, suggests that isoflurane is the better choice when anesthesia is needed for serial blood collection. However, availability of equipment for delivery of anesthetic, scavenging of waste gasses, familiarity of personnel with the anesthetic, and the potential effect of the anesthetic on research endpoints should all be considered in choosing between the 2 anesthetics.
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J Am Assoc Lab Anim · Jan 2006
A simple, inexpensive, and effective light- carrying laryngoscopic blade for orotracheal intubation of rats.
The research paradigm of using large laboratory animals, in which oroendotracheal intubations are relatively easy, is shifting toward the use of small animals, such as rodents, in which oropharyngeal access is limited, the arytenoid cartilage cycles are faster, and the glottis is much smaller. The considerable growth recently seen in preclinical imaging studies is accompanied by an increased number of rats and mice requiring in vivo intubation for airway management. ⋯ I fashioned a light-carrying laryngoscopic blade (laryngoscope) from readily available acrylic-polymethyl methacrylate tubing and used it to perform rapid, effective tracheal intubation in rats. The laryngoscope design and intubation techniques are presented.
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J Am Assoc Lab Anim · Jan 2006
Effect of noise on the morphology of the intestinal mucosa in laboratory rats.
To determine whether noise-induced stress disrupts the intestinal mucosa of laboratory rats, one group of 8 rats ("noise" rats) was subjected to 15 min of white noise (90 dB) daily for 3 wk. Another group ("quiet"rats) was housed for 3 wk in an acoustically similar room but with no additional noise. A 3rd group ("recovery" rats) was housed in the noise room for 3 wk and then in the quiet room for a further 3 wk. ⋯ In addition, mucosal epithelial cells of noise rats were often separated, sometimes detaching from the basement membrane, whereas those of quiet rats were intact. Behaviorally, noise rats exhibited significantly more grooming and rearing than quiet rats. Compared with noise rats, recovery rats showed no reduction in mast cell degranulation or mean width of villus lamina propria, but there were increased numbers of secreting goblet cells in villi adjacent to Peyer patches and some recovery of epithelial integrity.