scholarly journals Metabolic changes in the skin of rats of various ages. Oxygen consumption and uptake of glucose

1966 ◽  
Vol 98 (2) ◽  
pp. 374-377 ◽  
Author(s):  
BK Patnaik ◽  
MS Kanungo
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Changes

The contribution of insulation changes to the energy cost of avian molt

1997 ◽  
Vol 75 (3) ◽  
pp. 396-400 ◽  
Author(s):  
Paul C. Schieltz ◽  
Mary E. Murphy
Keyword(s):  
Oxygen Consumption ◽  
Critical Temperature ◽  
Energy Cost ◽  
Metabolic Changes ◽  
Zonotrichia Leucophrys ◽  
Lower Critical Temperature ◽  
Before And After ◽  
Two Temperatures ◽  
Per Se ◽  
Zonotrichia Leucophrys Gambelii

To evaluate the contribution of changes in plumage insulation to the energy cost of molt, we measured oxygen consumption by wintering White-crowned Sparrows (Zonotrichia leucophrys gambelii) before and after plucking 12, 24, or 36% of their plumage, and when they were replacing these feathers. Measurements were made at 20 and 25 °C, two temperatures bracketing the lower critical temperature (ca. 23 °C) of wintering Z. l. gambelii, and at 10 °C, well below the birds' lower critical temperature. For comparison, oxygen consumption by naturally molting birds was measured at 25 °C during summer. In these sparrows, feather loss resulted in increased oxygen consumption only at 10 °C and when feather loss was moderate (24% plumage; 10% increase) to intensive (36% plumage; 24% increase). Regrowth of 24 and 36% of plumage resulted in increased oxygen consumption at 20 °C (10 and 8.5%, respectively) and 10 °C (16 and 28%, respectively). Oxygen consumption by birds was unaffected by loss or regrowth of 12% of the plumage regardless of temperature, and at 25 °C, oxygen consumption was unaffected by the intensity of plumage replacement (0–36%). Comparison of oxygen consumption at 25 °C between naturally molting summer birds and treated winter birds revealed that the energy cost of molt and the apparent energy inefficiency of molt result neither from added thermoregulatory costs nor from the costs of feather synthesis per se, but seemingly from metabolic changes entrained by molt.

Metabolic Changes during Recovery in Normothermic versus Hypothermic Patients Undergoing Surgery and Receiving General Anesthesia and Epidural Local Anesthetic Agents 

1998 ◽  
Vol 88 (5) ◽  
pp. 1211-1218 ◽  
Author(s):  
Syrusse Motamed ◽  
Kristine Klubien ◽  
Michael Edwardes ◽  
Louise Mazza ◽  
Franco Carli
Keyword(s):  
Oxygen Consumption ◽  
General Anesthesia ◽  
Local Anesthetic ◽  
Visual Analogue Score ◽  
Sensory Block ◽  
Epidural Block ◽  
Metabolic Changes ◽  
Control Group ◽  
Epidural Blockade ◽  
Anesthetic Agents

Background Mild hypothermia is accompanied by metabolic changes. Epidural local anesthetic agents attenuate the surgical stress response, but it is not known whether they modulate thermal stress. Methods Thirty patients undergoing colorectal surgery, performed by one surgical team, received epidural 0.5% bupivacaine to achieve T3-S5 sensory block. They were then assigned randomly to two groups of 15 patients each. The control or unwarmed group was left to cool during surgery, whereas active warming was used in the warmed group. General anesthesia was induced by thiopentone, vecuronium, fentanyl, nitrous oxide in oxygen, and enflurane. At the end of surgery, both groups received epidural 0.25% bupivacaine to maintain a T5-L3 sensory block. Aural canal (core) and skin surface (15 sites) temperatures; oxygen consumption; pain visual analogue score; and concentrations of epinephrine, norepinephrine, glucose, cortisol, lactate, and free fatty acids in plasma were measured before epidural blockade, 30 min after epidural blockade, at the end of surgery, and for 4 h after surgery. Patients and those measuring the outcomes were unaware of group allocation. Results Core and mean skin temperatures decreased significantly in the control group (P < 0.001) but not in the warmed group. Catecholamine concentrations in plasma decreased significantly after epidural block, and although concentration of epinephrine in plasma increased from baseline sharply in the control group at the end of surgery (P = 0.004), it decreased in the warmed group (P = 0.007). During recovery, there was no difference between the two groups for norepinephrine concentrations in plasma, body weight-adjusted oxygen consumption, pain visual analogue score, and metabolites. Conclusions The postoperative metabolic changes obtained with epidural block were similar except for an attenuated concentration of epinephrine in normothermic patients compared with those who were mildly hypothermic.

scholarly journals Utilisation of substrates during tethered flight with and without lift generation in the African fruit beetle Pachnoda sinuata (Cetoniinae).

1998 ◽  
Vol 201 (15) ◽  
pp. 2333-2342 ◽  
Author(s):  
L Auerswald ◽  
P Schneider ◽  
G Gäde
Keyword(s):  
Amino Acids ◽  
Oxygen Consumption ◽  
Rapid Change ◽  
Metabolic Changes ◽  
Phase Changes ◽  
Second Phase ◽  
Glycogen Level ◽  
Tethered Flight ◽  
Rate Of Oxygen Consumption ◽  
Flight Muscles

We have investigated the pattern of metabolic changes during tethered flight with and without lift generation in the African fruit beetle Pachnoda sinuata. Two distinct metabolic phases occur during lift-generating flight. The first phase is characterised by a high rate of oxygen consumption and a rapid change in proline and alanine levels in the haemolymph and flight muscles and in glycogen level in the flight muscles. Carbohydrates are released from the fat body into the haemolymph. These carbohydrates are oxidised during the second phase. Changes in proline and alanine levels in the haemolymph and flight muscles and in glycogen level in the flight muscles are minor during the second phase and the rate of oxygen consumption is reduced. During lift-generating flight, metabolic changes are rapid. Proline concentrations in the haemolymph and flight muscles fall dramatically during the first 30 s of flight, while alanine concentrations rise concomitantly. While haemolymph concentrations of proline and alanine remain virtually unchanged thereafter, further changes in the levels of these amino acids occur in the flight muscles during 5 min of flight. The initial levels of the two amino acids in the flight muscles are re-established over 1 h of rest following a 5 min flight, while this process takes longer in the haemolymph. The concentration of haemolymph carbohydrates increases during the first 30 s of flight and declines thereafter during 5 min of flight. The pre-flight levels are restored after 1 h of subsequent rest. The stores of glycogen in the flight muscles are rapidly diminished during the first 10 s of flight and decrease at a lower rate during further flight lasting up to 5 min. A subsequent 1 h of rest is sufficient almost to restore pre-flight levels. Haemolymph lipid levels are slightly but significantly increased during 11 min of flight and after 1 h of subsequent rest. During flight without lift production, the metabolic changes are considerably slower and beetles fly approximately seven times longer than during lift-generating flight. Resting basalar (BM), dorso-ventral (DVM) and dorso-longitudinal (DLM) flight muscles show no differences in levels of proline, alanine and glycogen. After different periods of flight, during which lift and wing loading were minimised, the DVM was found to have the highest level of proline after 5 min of flight. Levels of alanine in the DVM were lower than in the DLM. There was no evidence to suggest that different flight muscles are specialised for either proline or carbohydrate utilisation. Proline and carbohydrates participate equally in supplying energy to the flight muscles during lift-generating flight. The contribution to the energy supply by the flight muscles is 54 %, while that of the haemolymph is 46 %.

scholarly journals Effect of external potassium concentrations, insulin and lactate on frog muscle potassium and respiratory rate

1960 ◽  
Vol 198 (6) ◽  
pp. 1360-1360
Author(s):  
L. B. Smillie ◽  
J. F. Manery
Keyword(s):  
Oxygen Consumption ◽  
Respiratory Rate ◽  
Frog Muscle ◽  
Metabolic Changes ◽  
Ringer Lactate ◽  
High Potassium ◽  
Insulin Effect ◽  
All Solutions ◽  
External Potassium

L. B. Smillie and J. F. Manery, "Effect of external potassium concentrations, insulin and lactate on frog muscle potassium and respiratory rate." Page 69: Table 1, Section 3, Insulin effect in the presence of lactate (May, June and July), column 3 (Exptl.) should read RIL for all solutions. Page 70: 1st column, 4th paragraph, 2nd sentence should read: A marked depression of the oxygen consumption. ... Page 71: 1st column, 3rd paragraph, 14th line should read: ... Ringer-lactate at the 5th and 6th hours being 136.9 and that in Ringer-insulin-lactate being 81.8 cu mm/gm/hr. Page 72: 1st column, 1st paragraph, 7th line should read: ... lactate when the metabolic changes invoked by high potassium were in operation. Page 73: 1st column, 2nd paragraph, 15th line should read: ... muscle and fluid analyses are presented in column 7. Page 73: 2nd column, 3rd paragraph, 6th line should read: That the depression of the potassium movement is specifically related to insulin and is unrelated to lactate is again implied. ... Page 74: 1st column, 1st paragraph, 8th line should read: ... the amounts of potassium taken from the medium. ... Page 76: 2nd column, 3rd paragraph, 9th line should read: ... that phosphocreatine began to be hydrolyzed. ... Page 77: Reference 1 should read: Manery, J. F., L. B. Smillie and K. E. Toye. J. Cell & Comp. Physiol. 44:336, 1954.

Regulation of renal ammoniagenesis in the dog with chronic metabolic acidosis: effect of a glutamine load

1985 ◽  
Vol 249 (5) ◽  
pp. F745-F752 ◽  
Author(s):  
A. Gougoux ◽  
P. Vinay ◽  
M. L. Halperin
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Acidosis ◽  
Amino Acid ◽  
Metabolic Changes ◽  
Glutamine Metabolism ◽  
Chronic Metabolic Acidosis ◽  
Atp Production ◽  
Amino Acid Release ◽  
Renal Oxygen Consumption ◽  
Acid Release

We recently emphasized that ATP is an obligatory product of renal glutamine metabolism and that all cells must remain in ATP balance. Based on this, we suggested that the maximum rate of renal ammoniagenesis in dogs with chronic metabolic acidosis may be limited by the rate of ATP utilization in the kidney. Since a large infusion of glutamine led to a twofold increase in renal ammoniagenesis in acidotic dogs, we wished to evaluate the renal metabolic changes that permitted this increment within the constraints of renal ATP balance. A large glutamine infusion did not lead to an augmented rate of ATP hydrolysis because renal oxygen consumption was not increased. Two major metabolic changes could explain this stimulation while maintaining ATP balance: first, ATP production from lactate by the kidney was decreased following the glutamine infusion; second, the metabolic fate of glutamine was changed so that more ammonium per ATP was synthesized (i.e., the rates of amino acid release into the renal vein were markedly enhanced, and gluconeogenesis was now a quantitatively significant process). 3-Mercaptopicolinate, an inhibitor of phosphoenolpyruvate carboxykinase, when infused with glutamine, apparently decreased the calculated rate of gluconeogenesis as expected; however, ammonium production did not decline, because the rate of amino acid release increased further, as did the rate of oxygen consumption. Therefore, a large glutamine infusion increased renal ammoniagenesis in dogs with chronic metabolic acidosis while maintaining ATP balance, because ATP production from other substrates was decreased and because the fate of glutamine metabolism was altered in that less ATP was formed per glutamine utilized.

Metabolic changes in the intact rat and excised tissues after thyroidectomy

1961 ◽  
Vol 200 (1) ◽  
pp. 55-57 ◽  
Author(s):  
R. R. Nielson ◽  
R. F. Loizzi ◽  
H. M. Klitgaard
Keyword(s):  
Oxygen Consumption ◽  
Similar Pattern ◽  
Intact Animal ◽  
Correlation Coefficients ◽  
Metabolic Changes ◽  
Basal Metabolism ◽  
Normal Value ◽  
Excised Tissues

The oxygen consumption of the intact rat and selected excised tissues was determined for 28 days following surgical thyroidectomy. By the 3rd day, the whole-animal basal metabolism showed a reduction to 90% of the normal value followed by a continuous fall to the basal level of 71% on the 7th day. In general, the excised tissues followed a similar pattern to that of the thyroidectomized intact animal. Heart, psoas and liver nearly paralleled the changes found in the whole animal, having correlation coefficients of 0.93, 0.93 and 0.97, respectively. Diaphragm ( r = 0.84) decreased sharply to 73% by day 3 then less rapidly to 42% on the final day of the study. Kidney ( r = 0.75) showed no decrease until day 2 then fell to a minimal value of 82% on day 20. Brain ( r = 0.77) declined only 16% reaching the basal level of 84% of normal 24 days after thyroidectomy.

scholarly journals Histolysis, Histogenesis, and Differentiation during Insect Metamorphosis in Relation to Metabolic Changes

Development ◽  
1953 ◽  
Vol 1 (3) ◽  
pp. 279-282
Author(s):  
Ivar Agrell
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Activity ◽  
Marked Decrease ◽  
Metabolic Changes ◽  
Limiting Factor ◽  
Heme Group ◽  
Enzyme Systems ◽  
Insect Metamorphosis ◽  
Prosthetic Heme Group ◽  
Protein Part

The most obvious change in metabolism during the more advanced type of insect metamorphosis is the change in the integral metabolic activity. After pupation there is first a marked decrease and later an increase of, for instance, the oxygen consumption. The respiratory metabolic curve is U-shaped. The cause of this change is a corresponding variation in the activity of oxidative enzyme systems. If one compares the variation of the spontaneous Mb-reduction and of the oxygen consumption in the fly Calliphora, one finds that the two curves have almost the same course (Agrell, 1947b). This shows an important co-operation of the dehydrogenase systems. The cytochrome system also shows a similar U-shaped variation during the period of metamorphosis, according to Wolsky (1938), Williams (1948) and Sacktor (1950). One limiting factor is the protein part of the enzymes, which is first broken down and later rebuilt (Agrell, 1946). Another limiting factor is the prosthetic heme group in the cytochromes (Williams, 1951).

Role of tissue hypermetabolism in stimulation of ventilation by dinitrophenol

1977 ◽  
Vol 43 (1) ◽  
pp. 72-74 ◽  
Author(s):  
S. Levine
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Metabolic Changes ◽  
Arterial Infusion ◽  
Anesthetized Dogs ◽  
Small Increments ◽  
Large Increments ◽  
Stimulation Of

Several authors have hypothesized that tissue hypermetabolism accounts for increases in ventilation (VE) elicited by 2,4-dinitrophenol. However, some data in the literature indicate that stimulation of VE by isomers of dinitrophenol is unrelated to tissue metabolic rate. To test this latter concept, we compared three different isomers of dinitrophenol (i.e., 2,4-dinitrophenol (2,4-DNP), 2,5-dinitrophenol (2,5,-DNP), 2,6-dinitrophenol (2,6-DNP) with respect to stimulation of VE and with respect to stimulation of oxygen consumption (VO2). In all experiments, 3–4 mg/kg of one dinitrophenol isomer was administered to chloralose anesthetized dogs by intra-arterial infusion. 2,4-DNP elicited large increments in both VE and VO2, 2,6-DNP elicited moderate increments in both VE and VO2, whereas 2,5-DNP elicited small increments in both VE and VO2. These observations demonstrate a correlation between ventilatory and metabolic changes affected by isomers of dinitrophenol. Accordingly, these results are consistent with the hypothesis that ventilatory stimulation by congeners of dinitrophenol is related to tissue hypermetabolism.

A Cytochemical Study of Glucose-6-Phosphatase (G-6-PASE) in Cells Participating in Atherogenesis of Rabbit Aorta

1975 ◽  
Vol 33 ◽  
pp. 460-461
Author(s):  
Sidney D. Kobernick ◽  
Edna A. Elfont ◽  
Neddra L. Brooks
Keyword(s):  
Lipid Metabolism ◽  
New Zealand ◽  
Aortic Wall ◽  
Rabbit Aorta ◽  
Plaque Formation ◽  
Metabolic Changes ◽  
Atherosclerotic Plaques ◽  
Cytochemical Study ◽  
Cellular Alteration ◽  
New Zealand White Rabbits

This cytochemical study was designed to investigate early metabolic changes in the aortic wall that might lead to or accompany development of atherosclerotic plaques in rabbits. The hypothesis that the primary cellular alteration leading to plaque formation might be due to changes in either carbohydrate or lipid metabolism led to histochemical studies that showed elevation of G-6-Pase in atherosclerotic plaques of rabbit aorta. This observation initiated the present investigation to determine how early in plaque formation and in which cells this change could be observed.Male New Zealand white rabbits of approximately 2000 kg consumed normal diets or diets containing 0.25 or 1.0 gm of cholesterol per day for 10, 50 and 90 days. Aortas were injected jin situ with glutaraldehyde fixative and dissected out. The plaques were identified, isolated, minced and fixed for not more than 10 minutes. Incubation and postfixation proceeded as described by Leskes and co-workers.

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