scholarly journals Kidney proteome changes provide evidence for a dynamic metabolism and regional redistribution of plasma proteins during torpor-arousal cycles of hibernation

2012 ◽  
Vol 44 (14) ◽  
pp. 717-727 ◽  
Author(s):  
Alkesh Jani ◽  
David J. Orlicky ◽  
Anis Karimpour-Fard ◽  
L. Elaine Epperson ◽  
Rae L. Russell ◽  
...  
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Plasma Proteins ◽  
Physiological State ◽  
Ground Squirrels ◽  
Endocytic Pathway ◽  
Protein Abundance ◽  
Regional Heterogeneity ◽  
Physiological Demands ◽  
Proteome Changes

Hibernating ground squirrels maintain homeostasis despite extreme physiological challenges. In winter, these circannual hibernators fast for months while cycling between prolonged periods of low blood flow and body temperature, known as torpor, and short interbout arousals (IBA), where more typical mammalian parameters are rapidly restored. Here we examined the kidney proteome for changes that support the dramatically different physiological demands of the hibernator's year. We identified proteins in 150 two-dimensional gel spots that altered by at least 1.5-fold using liquid chromatography and tandem mass spectrometry. These data successfully classified individuals by physiological state and revealed three dynamic patterns of relative protein abundance that dominated the hibernating kidney: 1) a large group of proteins generally involved with capturing and storing energy were most abundant in summer; 2) a select subset of these also increased during each arousal from torpor; and 3) 14 spots increased in torpor and early arousal were enriched for plasma proteins that enter cells via the endocytic pathway. Immunohistochemistry identified α2-macroglobulin and albumin in kidney blood vessels during late torpor and early arousal; both exhibited regional heterogeneity consistent with highly localized control of blood flow in the glomeruli. Furthermore, albumin, but not α2-macroglobulin, was detected in the proximal tubules during torpor and early arousal but not in IBA or summer animals. Taken together, our findings indicate that normal glomerular filtration barriers remain intact throughout torpor-arousal cycles but endocytosis, and hence renal function, is compromised at low body temperature during torpor and then recovers with rewarming during arousal.

scholarly journals Local Cerebral Blood Flow during Hibernation, a Model of Natural Tolerance to “Cerebral Ischemia”

1994 ◽  
Vol 14 (2) ◽  
pp. 193-205 ◽  
Author(s):  
Kai U. Frerichs ◽  
Charles Kennedy ◽  
Louis Sokoloff ◽  
John M. Hallenbeck
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Ischemia ◽  
Body Temperature ◽  
Physiological State ◽  
Ground Squirrels ◽  
Control Group ◽  
Spermophilus Tridecemlineatus ◽  
Destructive Processes ◽  
Natural Tolerance

The breakdown of cellular homeostasis and progressive neuronal destruction in cerebral ischemia appears to be mediated by a complex network of causes that are intricately interrelated. We have investigated a physiological state existing normally in nature in which mammals appear to tolerate the ordinarily detrimental effects of ischemia with reduced oxygen availability and to resist activation of self-destructive processes, i.e., mammalian hibernation. Ground squirrels (Spermophilus tridecemlineatus) were chronically implanted with arterial and venous catheters and telemetry devices for electroencephalography, electrocardiography, and monitoring of body temperature. The animals were placed in an environmental chamber at an ambient temperature of 5°C. Entrance into hibernation was characterized by a drop in heart rate followed by a gradual decline in body temperature and an isoelectric electroencephalogram. Cold-adapted active animals that were not hibernating served as controls. Cerebral blood flow (CBF) was measured in both groups with the autoradiographic [14C]iodoantipyrine method. Mean (±SD) mass-weighted CBF in the brain as a whole was 62 ± 16 ml/100 g/min (n = 4) in the control group but was reduced to ischemic levels, 7 ± 4 ml/100 g/min (n = 4), in the hibernating animals (p < 0.001). No neuropathological changes were found in similarly hibernating animals aroused from hibernation. Hibernation appears to be actively regulated, and hormonal factors may be involved. The identification and characterization of such factors and of the mechanisms used by hibernating species to increase ischemic tolerance and to blunt the destructive effects of ischemia may enable us to prevent or minimize the loss of homeostatic control during and after cerebral ischemia in other species.

Physiological characteristics of rats and ground squirrels during prolonged lethargic hypothermia

1960 ◽  
Vol 199 (3) ◽  
pp. 467-471 ◽  
Author(s):  
V. Popovic
Keyword(s):  
Blood Pressure ◽  
Body Temperature ◽  
Arterial Blood Pressure ◽  
Cold Water ◽  
Physiological State ◽  
Low Ph ◽  
Ground Squirrels ◽  
Adult Rats ◽  
Arterial Blood

After intensive cooling, rats can be maintained at constant body temperature during several hours in a cylinder surrounded by cold water. The rats live in lethargic hypothermia at a body temperature of 15°C for 8–10 hours but can recover only if the hypothermia has not lasted more than 5.5 hours, average time of ‘biological survival.’ After 6 or more hours at 15°C adult rats showed irreversible hemoconcentration, hypoglycemia, drop in arterial blood pressure and low pH of the blood, but no change in pulse rate. Artificially cooled ground squirrels survived 110 hours at a body temperature of 10°C, ‘biological survival’ time being only 75 hours. Hemoconcentration, low arterial blood pressure and hypoglycemia have also been found in lethargic ground squirrels during the last part of survival. They cannot be rescued by rewarming. The deeply cooled animal with stabilized temperature is in a physiological state that changes with time and ultimately leads to death. A recovery prognosis during long-term hypothermia has been attempted, and the cause of death has been discussed.

TEMPERATURE REGULATION IN EXERCISE

PEDIATRICS ◽  
1963 ◽  
Vol 32 (4) ◽  
pp. 691-702
Author(s):  
Sid Robinson
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Heat Stroke ◽  
The Body ◽  
Physiological Regulation ◽  
Temperature Changes ◽  
Metabolic Heat ◽  
Warm Blood ◽  
Hot Environments ◽  
Large Increments

The central body temperature of a man rises gradually during the first half hour of a period of work to a higher level and this level is precisely maintained until the work is stopped; body temperature then slowly declines to the usual resting level. During prolonged work the temperature regulatory center in the hypothalamus appears to be reset at a level which is proportional to the intensity of the work and this setting is independent of environmental temperature changes ranging from cold to moderately warm. In hot environments the resistance to heat loss may be so great that all of the increased metabolic heat of work cannot be dissipated and the man's central temperature will rise above the thermostatic setting. If this condition of imbalance is continued long enough heat stroke will ensue. We have found that in a 3 mile race lasting only 14 minutes on a hot summer day a runner's rectal temperature may rise to 41.1°C., with heat stroke imminent. The physiological regulation of body temperature of men in warm environments and during the increased metabolic heat production of work is dependent on sweating to provide evaporative cooling of the skin, and on adjustments of cutaneous blood flow which determine the conductance of heat from the deeper tissues to the skin. The mechanisms of regulating these responses during work are complex and not entirely understood. Recent experiments carried out in this laboratory indicate that during work, sweating may be regulated by reflexes originating from thermal receptors in the veins draining warm blood from the muscles, summated with reflexes from the cutaneous thermal receptors, both acting through the hypothalamic center, the activity of which is increased in proportion to its own temperature. At the beginning of work the demand for blood flow to the muscles results in reflex vasoconstriction in the skin. As the body temperature rises the thermal demand predominates and the cutaneous vessels dilate, increasing heat conductance to the skin. Large increments in cardiac output and compensatory vasoconstriction in the abdominal viscera make these vascular adjustments in work possible without circulatory embarrassment.

The liver proteome response to torpor in a basoendothermic mammal, Tenrec ecaudatus, provides insights into the evolution of homeothermy

2021 ◽  
Author(s):  
Jane I Khudyakov ◽  
Michael D Treat ◽  
Mikayla C Shanafelt ◽  
Jared S Deyarmin ◽  
Benjamin A Neely ◽  
...  
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Metabolic Pathways ◽  
Molecular Basis ◽  
Protein Abundance ◽  
Poor Control ◽  
High Body ◽  
Liver Proteome ◽  
The Common

Many mammals use adaptive heterothermy (e.g. torpor, hibernation) to reduce metabolic demands of maintaining high body temperature (Tb). Torpor is typically characterized by coordinated declines in Tb and metabolic rate (MR) followed by active rewarming. Most hibernators experience periods of euthermy between bouts of torpor during which homeostatic processes are restored. In contrast, the common tenrec, a basoendothermic Afrotherian mammal, hibernates without interbout arousals and displays extreme flexibility in Tb and MR. We investigated the molecular basis of this plasticity in tenrecs by profiling the liver proteome of animals that were active or torpid with high and more stable Tb (~32°C) or lower Tb (~14°C). We identified 768 tenrec liver proteins, of which 50.9% were differentially abundant between torpid and active animals. Protein abundance was significantly more variable in active cold and torpid compared to active warm animals, suggesting poor control of proteome abundance. Our data suggest that torpor in tenrecs may lead to mismatches in protein pools due to poor coordination of anabolic and catabolic processes. We propose that the evolution of endothermy leading to a more realized homeothermy of boreoeutherians likely led to greater coordination of homeostatic processes and reduced mismatches in thermal sensitivities of metabolic pathways.

Effect of two methods of hand heating on body temperature, forearm blood flow, and deep venous oxygen saturation

1990 ◽  
Vol 259 (5) ◽  
pp. E639-E643 ◽  
Author(s):  
I. W. Gallen ◽  
I. A. Macdonald
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Oxygen Content ◽  
Forearm Blood Flow ◽  
Venous Blood ◽  
Blood Oxygen ◽  
Left Hand ◽  
Venous Oxygen Saturation ◽  
Baseline Values ◽  
Healthy Females

Two methods of hand heating [warmed blanket 40 degrees C (WB) and warm-air box 55 degrees C (WA)] were compared with the effect of no heating (control) in six healthy females. After 30 min baseline, the left hand was either heated for 1 h or not heated. Measurements were made of skin temperature (ST), core temperature (CT), right forearm (FBF) and skin blood flow (SBF), and right forearm deep venous blood oxygen content with and without occlusion of the hand circulation. CT rose above baseline in WB (by +0.2 degrees C, P less than 0.01) but not with control or WA. Abdominal ST rose only with WB (by +0.66 degrees C above baseline, P less than 0.01). FBF increased above baseline values with both WA (by +10 ml.l forearm-1.min-1) and WB (by +12 ml.l forearm-1.min-1), but neither was significantly greater than the control. SBF increased above baseline only with WB (by +202 mV, P less than 0.01), and this was significantly greater than control SBF. With an occluded hand circulation, deep venous oxygen content rose above baseline values with WB only (+6.0%, P less than 0.01) but was not greater than control with either method of hand heating. We conclude that using a warm-air box has less effect than a heated blanket on the measured variables.

Regional heterogeneity of cerebral blood flow response to graded volume-controlled hemorrhage

1996 ◽  
Vol 22 (10) ◽  
pp. 1026-1033 ◽  
Author(s):  
K. F. Waschke ◽  
M. Riedel ◽  
D. M. Albrecht ◽  
K. van Ackern ◽  
W. Kuschinsky
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Heterogeneity ◽  
Blood Flow Response ◽  
Flow Response ◽  
Volume Controlled

scholarly journals Body temperature influences regional tissue blood flow during retrograde cerebral perfusion

1997 ◽  
Vol 114 (3) ◽  
pp. 440-447 ◽  
Author(s):  
Akihiko Usui ◽  
Keiji Oohara ◽  
Fumihiko Murakami ◽  
Hideki Ooshima ◽  
Mitsuo Kawamura ◽  
...  
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Cerebral Perfusion ◽  
Tissue Blood Flow ◽  
Retrograde Cerebral Perfusion

Effects of immersion of the hand in cold water on digital blood flow

1965 ◽  
Vol 20 (1) ◽  
pp. 61-64 ◽  
Author(s):  
A. C. L. Hsieh ◽  
T. Nagasaka ◽  
L. D. Carlson
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Cold Water ◽  
Regression Equation ◽  
Finger Blood Flow ◽  
Circulatory Response ◽  
Cold Induced Vasodilatation ◽  
Digital Blood Flow

The temperatures of the tip of the middle fingers ( Ts) of nine comfortably warm subjects have been recorded during immersion of all the fingers of one hand in a 27–liter bath containing slowly stirred water at temperatures ranging from 4.6 to 40 C ( Tw). Blood flow ( F = ml/cm2 per min) was estimated from the average Ts for the last 15 min of a 20-min period, Tw and body temperature ( Tb) by using the equation: F = 1,087 x K( Ts – Tw)/ ( Tb – Ts). (K = 0.0134 kcal/cm2 per min per °C.) The increase in F per °C reduction in Tw below 10 C was 0.16 ± 0.077 (P < .05). This value gives a measure of the vasodilatation occasioned by immersion in water below 10 C. The sample regression equation of F on Tw was: F = 4.1 – .16 Tw ± 0.17 (n = 27; range of Tw = 4.6 to 10 C). This method of estimating blood flow at several levels of Tw describes more fully the peripheral circulatory response to cold than methods in which only one level of Tw is used. cold-induced vasodilatation; temperature and finger blood flow Submitted on August 28, 1963

PGE1-induced intestinal secretion: mechanism of enhanced transmucosal protein efflux.

1979 ◽  
Vol 236 (6) ◽  
pp. E788
Author(s):  
D N Granger ◽  
J S Shackleford ◽  
A E Taylor
Keyword(s):  
Blood Flow ◽  
Mesenteric Artery ◽  
Plasma Proteins ◽  
Structural Damage ◽  
Prostaglandin E1 ◽  
Intestinal Secretion ◽  
Fluid Exchange ◽  
Tissue Samples ◽  
Volume Absorption ◽  
Regional Hemodynamics

The effects of local intra-arterial prostaglandin E1 (PGE1) infusion on net transmucosal volume and protein fluxes, lymphatic volume and protein fluxes, and regional hemodynamics were ascertained in autoperfused segments of cat ileum. After acquiring control values (and tissue samples) for the various parameters, PGE1 (5.0 microgram/min) was infused directly into the superior mesenteric artery. The PGE1 infusions resulted in dramatic increases in ileal lymphatic volume and protein fluxes and blood flow. Infusion of PGE1 caused a reversion of net mucosal volume absorption to net secretion and an increased loss of plasma proteins into the lumen. Ultrastructural analysis of tissue samples taken during the PGE1 infusion indicate major structural damage to the mucosal membrane. The physiological and ultrastructural data acquired in this study suggest that 1) the increased transmucosal protein efflux during intra-arterial PGE1 infusions results from an alteration in mucosal transcapillary fluid exchange and 2) a significant portion of PGE1-induced ileal secretion is passively mediated.

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