Biomedical subjects

E W Pfeiffer

Publications and source records attributed to E W Pfeiffer.

16 recordsLinked to original sources

PubMed1995

Dioxins in Vietnam.

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Environmental Pollution↗

PubMed1992

The effects of dietary deprivation on body temperature and oxygen consumption in black-tailed prairie dogs (Cynomys ludovicianus).

1. Body temperature (Tb) and oxygen consumption (VO2) were compared between fed (Control), food and water deprived (FWD), and water deprived (WD) black-tailed prairie dogs, in the month of January. 2. Mean Tb of Control black-tailed prairie dogs (36.2 degrees C) was significantly different from FWD (33.4 degrees C) and WD (30.4 degrees C) black-tailed prairie dogs. 3. VO2 was not significantly different between FWD and Control black-tailed prairie dogs (4.4 and 4.0 ml O2/kg/hr, respectively), while VO2 was significantly different between WD and Control animals (2.9 and 4.0 ml O2/kg/hr, respectively). 4. These findings are discussed as possible mechanisms for conserving body water.

Animals↗

PubMed1977

Effects of cold exposure and dehydration on renal function in black-tailed prairie dogs.

Black-tailed prairie dogs (Cynomys ludovicianus) were deprived of food and water for several weeks during the fall and winter in a cold-room hibernaculum (Ta 5-8 degrees C), and for several days at room temperature during the summer. Body temperatures (Tb) were determined periodically in nine animals by radiotransmitters implanted in the abdomen. Animals deprived of food and water in the summer were killed when maximum urine concentration was achieved. Eight animals in the winter were active when killed after 7-35 days in the hibernaculum with Tb between 18 and 36 degrees C. Five animals that became torpid periodically in the winter were killed after 19-42 days in the hibernaculum when their Tb indicated torpor (Tb less than 13 degrees C). Active animals in the summer and winter possessed pronounced renal corticomedullary urea and sodium concentration gradients. Torpid animals lacked these gradients and had lower urine and plasma osmotic concentrations than active animals. Plasma urea values and terminal osmolal U/P ratios were lowest in torpid prairie dogs.

Animals↗

PubMed1975

Urea excretion in the hibernating Columbian ground squirrel (Spermophilus columbianus).

Hibernation was induced in Columbian ground squirrels by placing them in refrigerated cages equipped with urine-collection pans. On arousal, urine and blood were collected from each animal, which was then allowed to reenter hibernation. After several days the animal was sacrificed and bladder urine and another blood sample were taken. In addition, four active non-hibernating ground squirrels were placed in a cage at room temperature with neither food or water. Urine was collected at 9 and 26 hours and blood was collected at 0 and 26 hours. Although only seven of ten hibernating squirrels had a higher blood-urea level when sacrificed than during the previous arousal, the other three had very high levels in the arousal period and probably further excreted urea before entering hibernation. When total body urea was calculated on a body weight basis, all except one animal showed a greater level of urea during hibernation than in the previous arousal. During their period of dehydration, the non-hibernating summer squirrels showed a marked decrease in blood urea. The osmotic concentration of the urine from these squirrels was due less to urea than that excreted during arousal by hibernating squirrels. Thus, it appears that urea accumulates in the blood during hibernation and is excreted in the urine during arousal.

Animals↗

PubMed1973