Central effects of 5-hydroxytryptamine and noradrenaline on body temperature and oxygen consumption in infant rats

1971 ◽  
Vol 27 (3) ◽  
pp. 274-276 ◽  
Author(s):  
R. Tirri
2021 ◽  
Vol 22 (9) ◽  
pp. 4366
Author(s):  
Rebecca L. Paszkiewicz ◽  
Richard N. Bergman ◽  
Roberta S. Santos ◽  
Aaron P. Frank ◽  
Orison O. Woolcott ◽  
...  

The authors wish to make the following corrections to this paper [...]


1991 ◽  
Vol 69 (7) ◽  
pp. 1842-1847 ◽  
Author(s):  
Gregory K. Snyder ◽  
Joseph R. Coelho ◽  
Dalan R. Jensen

In chicks the ability to regulate body temperature to adult levels develops during the first 2 weeks of life. We examined whether the ability of young chicks to regulate body temperature is increased by elevated levels of the thyroid hormone 3,3′5-triiodothyronine. By 13 days following hatch, body temperatures of chicks were not significantly different from those expected for adult birds. Furthermore, at an ambient temperature of 10 °C, 13-day-old control chicks were able to maintain body temperature, and elevated serum thyroid hormone levels did not increase rates of oxygen consumption or body temperature above control values. Six-day-old chicks had body temperatures that were significantly lower than those of the 13-day-old chicks and were not able to regulate body temperature when exposed to an ambient temperature of 10 °C. On the other hand, 6-day-old chicks with elevated serum thyroid hormone had significantly higher rates of oxygen consumption than 6-day-old control chicks, and were able to maintain constant body temperatures during cold exposure. The increased oxygen consumption rates and improved ability to regulate body temperature during cold exposure were correlated with increased citrate synthase activity in skeletal muscle. Our results support the argument that thyroid hormones play an important role in the development of thermoregulatory ability in neonate birds by stimulating enzyme activities associated with aerobic metabolism.


1993 ◽  
Vol 265 (5) ◽  
pp. R1179-R1183 ◽  
Author(s):  
R. H. Derijk ◽  
P. J. Strijbos ◽  
N. van Rooijen ◽  
N. J. Rothwell ◽  
F. Berkenbosch

Increases in thermogenesis and body temperature (fever) frequently accompany infection or injury and are thought to be mediated by endogenous pyrogens (e.g. cytokines), which are released from activated immune cells such as macrophages. Therefore, we have investigated the effect of selective elimination of peripheral macrophages on the changes in oxygen consumption (VO2) and colonic temperature in response to bacterial lipopolysaccharide (LPS) in the rat. Peripheral macrophages were depleted by intravenous injection of liposomes containing the drug dichloromethylene diphosphonate (Cl2MDP). Resting oxygen consumption and colonic temperatures were not affected by macrophage elimination. In intact rats, peripheral injection of LPS (0.1-0.5 mg/kg) elicited an increase in colonic temperature and in oxygen consumption that declined at higher doses (2.5 mg/kg). The pyrogenic and thermogenic responses to LPS were significantly attenuated in rats in which peripheral macrophages were eliminated. Previously, we have reported that elimination of macrophages blunts the plasma interleukin-1 (IL-1) response to LPS. Here we show that elimination of macrophages does not affect the increase in plasma IL-6 concentrations in response to LPS. These data indicate that the pyrogenic and thermogenic responses to LPS are at least in part dependent on mechanisms involving peripheral macrophages, and that peripherally produced IL-1 rather than IL-6 may be an important mediator of the changes in oxygen consumption and colonic temperature in response to LPS.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5600 ◽  
Author(s):  
Rebecca Naomi Cliffe ◽  
David Michael Scantlebury ◽  
Sarah Jane Kennedy ◽  
Judy Avey-Arroyo ◽  
Daniel Mindich ◽  
...  

Poikilotherms and homeotherms have different, well-defined metabolic responses to ambient temperature (Ta), but both groups have high power costs at high temperatures. Sloths (Bradypus) are critically limited by rates of energy acquisition and it has previously been suggested that their unusual departure from homeothermy mitigates the associated costs. No studies, however, have examined how sloth body temperature and metabolic rate vary with Ta. Here we measured the oxygen consumption (VO2) of eight brown-throated sloths (B. variegatus) at variable Ta’s and found that VO2 indeed varied in an unusual manner with what appeared to be a reversal of the standard homeotherm pattern. Sloth VO2 increased with Ta, peaking in a metabolic plateau (nominal ‘thermally-active zone’ (TAZ)) before decreasing again at higher Ta values. We suggest that this pattern enables sloths to minimise energy expenditure over a wide range of conditions, which is likely to be crucial for survival in an animal that operates under severe energetic constraints. To our knowledge, this is the first evidence of a mammal provisionally invoking metabolic depression in response to increasing Ta’s, without entering into a state of torpor, aestivation or hibernation.


1992 ◽  
Vol 163 (1) ◽  
pp. 139-151 ◽  
Author(s):  
R. M. BEVAN ◽  
P. J. BUTLER

Six tufted ducks were trained to dive for food at summer temperatures (air, 26°C, water, 23°C) and at winter temperatures (air, 5.8°C, water 7.4°C). The mean resting oxygen consumption (Voo2) a t winter temperatures (rwin) was 90% higher than that at summer temperatures (Tsum), but deep body temperatures (Tb) were not significantly different. Diving behaviour and mean oxygen consumption for dives of mean duration were similar at Twin and at Tsum, although the mean oxygen consumption for surface intervals of mean duration was 50% greater at Twin and Tb was significantly lower (1°C) at the end of a series of dives in winter than it was in summer. There appears to be an energy saving of 67 J per dive during winter conditions and this may, at least partially, be the result of the metabolic heat produced by the active muscles being used to maintain body temperature. While at rest under winter conditions, this would be achieved by shivering thermogenesis. Thus, the energetic costs of foraging in tufted ducks in winter are not as great as might be expected from the almost doubling of metabolic rate in resting birds.


1982 ◽  
Vol 243 (1) ◽  
pp. R104-R111 ◽  
Author(s):  
A. H. Rezvani ◽  
C. J. Gordon ◽  
J. E. Heath

Male New Zealand White rabbits, Oryctolagus cuniculus, were stereotaxically implanted with a guide tube above the preoptic/anterior hypothalamus area (PO/AH) for the injection of the opioid peptide, beta-endorphin (beta-E), naloxone, sodium salicylate, or physiological saline. PO/AH and ear temperature, oxygen consumption, and evaporative heat loss (EHL) were recorded in free-moving rabbits before and after injection of saline followed with beta-E, naloxone, or sodium salicylate at ambient temperatures (Ta) of 2-31 degrees C. A 5-micrograms injection of beta-E promoted a rapid reduction in ear temperature followed by a prolonged rise in PO/AH (body) temperature. Preinjection with an isovolumetric amount of the opiate antagonist, naloxone, inhibited the thermoregulatory effects of beta-E. The beta-E-induced rise in body temperature was directly correlated with Ta. beta-E had no effect on oxygen consumption at Ta's of 5 and 27 degrees C. When measured 30 min after injection, beta-E demonstrated a significant inhibition of EHL at Ta's of 27 and 31 but not 5 degrees C. The beta-E-induced rise in body temperature was not antagonized with preinjections of sodium salicylate in the PO/AH. These data indicate that beta-E promotes a regulated increase in body temperature. The mechanism of activation appears to be distinct from that of an infectious fever.


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