Food deprivation and refeeding in the camel (Camelus dromedarius)

1992 ◽  
Vol 262 (6) ◽  
pp. R1000-R1005 ◽  
Author(s):  
K. Dahlborn ◽  
S. Benlamlih ◽  
R. Zine-Filali ◽  
A. Gueroulali ◽  
J. Hossaini-Hilali ◽  
...  
Keyword(s):  
Body Temperature ◽  
Food Deprivation ◽  
Water Intake ◽  
Plasma Volume ◽  
Glucose Concentration ◽  
Urine Volume ◽  
The Body ◽  
Total Plasma ◽  
Plasma Protein Concentration ◽  
Total Plasma Protein

Camels thrive in arid and semiarid areas, although food and water frequently are scarce. However, the mechanisms enabling camels to withstand food deprivation are poorly understood. In this study four female camels were totally deprived of food for 4 days. Their body weight decreased by 6%. Food deprivation caused no change in total plasma protein concentration in the camel, indicating that no alterations in plasma volume occurred. When the first meal was withheld water intake was unchanged. Next day the camels showed signs of hydration with a decreased plasma Na+ concentration and an increased excretion of diluted urine. In the afternoon water intake decreased. Urine K+ excretion fell the first day and urine volume and Na+ excretion from the third day. No activation of the renin-angiotensin-aldosterone system (RAAS) was observed. Plasma and urine urea concentration increased during food deprivation. Plasma glucose concentration and plasma cortisol and thyroxine levels did not change. Body temperature decreased during food deprivation. After refeeding, total plasma proteins increased temporarily by 12%, and a threefold increase in RAAS was seen, implying that both plasma volume and RAAs changed rapidly. Our results show that fluid balance was only slightly affected in the food-deprived camel. We suggest that strategies for the camel to endure food deprivation include maintenance of plasma volume and glucose concentration and a lowering of the body temperature.

Nontraditional effects of protein binding and hematocrit on uptake of indocyanine green by perfused rat liver

1997 ◽  
Vol 273 (1) ◽  
pp. G227-G238 ◽  
Author(s):  
P. Ott ◽  
R. A. Weisiger
Keyword(s):  
Indocyanine Green ◽  
Protein Binding ◽  
Plasma Volume ◽  
Protein Concentration ◽  
Hepatic Clearance ◽  
Hepatic Uptake ◽  
Perfused Rat Liver ◽  
Total Plasma ◽  
Plasma Protein Concentration ◽  
Total Plasma Protein

We used a novel parameter-free approach to study the role of protein binding in the hepatic clearance of indocyanine green (ICG) from reconstituted pig blood by perfused rat liver. Either perfusate total plasma protein concentration or hematocrit was changed. By analyzing protein concentration ratios or plasma volume ratios relative to ratios of intrinsic hepatic clearance of ICG (K), it was possible to evaluate current models of hepatic uptake of protein-bound ligands without precise knowledge of some of the model parameters. A four-fold increase in the total plasma protein concentration produced only a 36% decrease in K. This was substantially less than predicted by the traditional model, where K is proportional to the free concentration of ligand. Because an unstirred water layer effect could not by itself account for the observations, the effects of binding disequilibrium in the sinusoids or uptake directly from the bound pool had to be considered. To discriminate, hematocrit was increased from 15% to 29%, causing a 20% decrease in the sinusoidal plasma volume. A significant reduction in K strongly suggested a sinusoidal binding disequilibrium effect. The dissociation rate constant predicted by this model was confirmed by in vitro measurement, further supporting this interpretation. The simple experimental design and its parameter-free evaluation provide a new tool for investigating the hepatic uptake of protein-bound ligands.

Factors Affecting Blood Volumes in Hypophysectomized Female Rats

1957 ◽  
Vol 191 (2) ◽  
pp. 296-300 ◽  
Author(s):  
Charles F. Bond ◽  
Samuel L. Leonard
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Plasma Protein ◽  
Plasma Volume ◽  
Weight Ratio ◽  
The Body ◽  
Female Rats ◽  
Body Weight Ratio ◽  
Plasma Protein Concentration ◽  
Total Plasma Protein

Plasma volume by the dye (T-1824) method, hematocrit, hemoglobin concentration and plasma specific gravity were determined, and from them total blood and erythrocyte volumes and plasma protein concentration were derived in hypophysectomized female rats fed standard and enriched diets. The effects of insulin, growth hormone and prolactin were also studied. Hypophysectomy decreased the plasma volume and established a lower, stable plasma volume/body weight ratio which was not influenced significantly by diet or hormones. The erythrocyte volume/body weight ratio markedly reduced after hypophysectomy, was readily increased by the enriched diet, especially in younger animals. Insulin injections did not alter the blood picture or increase the body weight. Growth hormone increased both plasma and erythrocyte volumes proportionally to the elevation in body weight and also increased the total plasma protein. Prolactin, possibly contaminated with growth hormone as noted by the tibia test, acted similarly to growth hormone but to a lesser extent.

Fluid, Electrolyte, and Renal Indices of Hydration during 11 Days of Controlled Caffeine Consumption

2005 ◽  
Vol 15 (3) ◽  
pp. 252-265 ◽  
Author(s):  
Lawrence E. Armstrong ◽  
Amy C. Pumerantz ◽  
Melissa W. Roti ◽  
Daniel A. Judelson ◽  
Greig Watson ◽  
...  
Keyword(s):  
Urine Volume ◽  
Treatment Phase ◽  
Urine Specific Gravity ◽  
Caffeine Intake ◽  
Electrolyte Balance ◽  
Total Plasma ◽  
Caffeine Consumption ◽  
Urine Color ◽  
Total Plasma Protein ◽  
Healthy Males

This investigation determined if 3 levels of controlled caffeine consumption affected fluid-electrolyte balance and renal function differently. Healthy males (mean ± standard deviation; age, 21.6 ± 3.3 y) consumed 3 mg caffeine · kg−1 · d−1 on days 1 to 6 (equilibration phase). On days 7 to 11 (treatment phase), subjects consumed either 0 mg (C0; placebo; n = 20), 3 mg (C3; n = 20), or 6 mg (C6; n = 19) caffeine · kg−1 · d−1 in capsules, with no other dietary caffeine intake. The following variables were unaffected (P > 0.05) by different caffeine doses on days 1, 3, 6, 9, and 11 and were within normal clinical ranges: body mass, urineosmolality, urine specific gravity, urine color, 24-h urine volume, 24-h Na+ and K+ excretion, 24-h creatinine, blood urea nitrogen, serum Na+ and K+, serum osmolality, hematocrit, and total plasma protein. Therefore, C0, C3, and C6 exhibited no evidence of hypohydration. These findings question the widely accepted notion that caffeine consumption acts chronically as a diuretic.

Ecology of parasitism of nestling American kestrels by Carnus hemapterus (Diptera: Carnidae)

1997 ◽  
Vol 75 (12) ◽  
pp. 2021-2026 ◽  
Author(s):  
Russell D. Dawson ◽  
Gary R. Bortolotti
Keyword(s):  
Protein Concentration ◽  
Total Plasma ◽  
Negative Effects ◽  
Plasma Protein Concentration ◽  
North Central ◽  
American Kestrel ◽  
American Kestrels ◽  
Total Plasma Protein ◽  
Carnus Hemapterus ◽  
Basic Biology

Little is known about the basic biology of Carnus hemapterus (Diptera: Carnidae), a haematophagous parasite of nestling birds. We therefore explored the patterns of C. hemapterus infestations by repeatedly examining American kestrel (Falco sparverius) nestlings from 50 nests in north-central Saskatchewan. Most infestations occurred before chicks were 12 days old and were more frequent early in the breeding season. Nestlings from larger broods had higher prevalences of C. hemapterus, but we did not detect differences in intensity of infestations between broods of different sizes. Within broods up to 5 days old, the heaviest nestlings were preferentially infested by C. hemapterus. Although evidence suggests that ectoparasite infestations are harmful to hosts, we did not detect any mortality attributable to C. hemapterus. Similarly, we did not observe negative effects of C. hemapterus infestations on nestling mass, length of the tenth primary flight feather, haematocrit, or total plasma protein concentration at 24 days old.

The influence of long-term melatonin administration on basic physiological and metabolic variables of young Wistar:Han rats

Biologia ◽  
2006 ◽  
Vol 61 (3) ◽  
Author(s):  
Monika Kassayová ◽  
Martina Marková ◽  
Bianka Bojková ◽  
Eva Adámeková ◽  
Peter Kubatka ◽  
...  
Keyword(s):  
Body Weight ◽  
Water Intake ◽  
Glucose Concentration ◽  
Tap Water ◽  
Serum Glucose ◽  
The Body ◽  
Male Rats ◽  
Epididymal Fat ◽  
Food And Water Intake

AbstractThe question of effects of long-term melatonin (MEL) administration have not yet been explained sufficiently, especially its metabolic consequences in young persons and animals. The aim of the present study was to analyze the effects of MEL given during prolonged time (for 3 months) and chronically (for 6 months) at the dose of 4 µg/mL of tap water, on the selected metabolic and hormonal parameters in young female and male Wistar:Han (WH) rats. The weights of selected organs, tissues, body weight gains and food and water intake were registered. Six weeks aged rats were adapted to standard housing conditions and light regimen L:D=12:12 h, fed standard laboratory diet and drank tap water (controls) or MEL solution ad libitum; finally they were sacrificed after overnight fasting. Prolonged MEL administration decreased serum glucose concentration and increased triacylglycerol and malondialdehyde concentration/content in the liver in females. In males MEL increased concentrations of serum phospholipids, corticosterone and liver malondialdehyde. MEL treatment reduced the body weight in both sexes and weight of epididymal fat in males, without any alterations of food and water intake. Chronic MEL administration reduced serum glucose concentration and increased concentration/content of glycogen, triacylglycerol and cholesterol in the liver and glycogen concentration/content in heart muscle in males. In females, the significant rise of serum corticosterone concentration and liver malondialdehyde content was recorded. MEL significantly increased liver weight and decreased thymus weight in males. MEL administration increased temporarily water intake in males, body and epididymal fat weights were similar to that in controls. Body weight of MEL drinking females was reduced in the 1st half of experiment only; the food and water intake did not differ from control group. The response in WH rats on MEL was more prominent as in the Sprague-Dawley strain (our previous studies). Male rats were generally more affected, probably due to higher daily and total consumption of melatonin.

Effects of food deprivation on daily changes in body temperature and behavioral thermoregulation in rats

2000 ◽  
Vol 278 (1) ◽  
pp. R134-R139 ◽  
Author(s):  
Tamae Yoda ◽  
Larry I. Crawshaw ◽  
Kyoko Yoshida ◽  
Liu Su ◽  
Takayoshi Hosono ◽  
...  
Keyword(s):  
Body Temperature ◽  
Food Deprivation ◽  
Escape Behavior ◽  
The Body ◽  
Behavioral Thermoregulation ◽  
Cold Environments ◽  
The Face ◽  
Regulate Body Temperature ◽  
Behavioral Mechanisms ◽  
Escape Behaviors

Homeothermic animals regulate body temperature (Tb) by using both autonomic and behavioral mechanisms. In the latter process, animals seek out cooler or warmer places when they are exposed to excessively hot or cold environments. Thermoregulation is affected by the state of energy reserves in the body. In the present study, we examine the effects of 4-day food deprivation on circadian changes in Tb and on cold-escape and heat-escape behaviors in rats. Continuous measurement of Tb during food deprivation indicated that the peak Tb amplitude was not different from baseline values, but the trough amplitude continuously decreased after the onset of food deprivation. Cold-escape behavior was facilitated by food deprivation, whereas heat-escape behavior was unchanged. After the termination of food deprivation, the lowered Tb returned to normal on the first day. However, cold-escape behavior was still facilitated on the third day after food reintroduction. Autonomic and behavioral thermoregulatory effectors are modulated in the face of food shortage so as to maintain optimal performance during the active period, whereas increasing energy conservation occurs during the quiescent phase.

Equine plasma and blood volumes decrease with dehydration but subsequently increase with exercise

1993 ◽  
Vol 75 (2) ◽  
pp. 1002-1008 ◽  
Author(s):  
J. R. Naylor ◽  
W. M. Bayly ◽  
H. C. Schott ◽  
P. D. Gollnick ◽  
D. R. Hodgson
Keyword(s):  
Protein Concentration ◽  
O2 Consumption ◽  
Total Plasma ◽  
Plasma Protein Concentration ◽  
Low Intensity ◽  
Equine Plasma ◽  
Total Plasma Protein ◽  
Low Intensity Exercise ◽  
Circulating Volume ◽  
Blood Volumes

The effects of dehydration and 40 min of exercise at approximately 40% of maximal O2 consumption on plasma volume (PV) and blood volume (BV) were studied in six horses. Horses were exercised while euhydrated (C); 4 h after administration of furosemide (1.0 mg/kg i.v.; FDH), which induced isotonic dehydration; and after 30 h without water (DDH), which caused hypertonic dehydration. Dehydration resulted in decreases of 6.3 and 9.9% for PV and BV, respectively, with FDH and 10.7 and 8.5%, respectively, with DDH. During exercise in C, PV and BV increased by 12.7 and 20.0%, respectively; during exercise with FDH, they increased by 11.7 and 26.1%, respectively; and during exercise with DDH, PV decreased by 1.3% from predehydration values, while BV increased by 18.7%. Hematocrit and total plasma protein concentration rose to higher values throughout exercise in FDH and DDH than in C; plasma [Na+] was higher in DDH than in FDH and C, [Cl-] was higher in DDH and lower in FDH than in C, and [K+] was lower in FDH and DDH than in C through exercise and recovery. From these results, we conclude that increases in PV and BV are normal features of low-intensity exercise in the horse. The increases in BV not only augment O2 carriage but also help maintain circulating volume. These increases can be modified by preexercise dehydration, the nature of which affects the extent of modification.

EFFECTS OF THE TEMPERATURE OF THE ENVIRONMENT AND THE DRINKING WATER ON THE BODY TEMPERATURE AND WATER CONSUMPTION OF SHEEP

1962 ◽  
Vol 42 (1) ◽  
pp. 1-8 ◽  
Author(s):  
C. B. Bailey ◽  
R. Hironaka ◽  
S. B Slen
Keyword(s):  
Drinking Water ◽  
Body Temperature ◽  
Water Intake ◽  
Water Consumption ◽  
Environmental Temperature ◽  
The Body ◽  
Average Temperature ◽  
Subcutaneous Tissues ◽  
Environmental Temperatures ◽  
Reduced Water

Temperatures in the rumen, rectum, and subcutaneous tissues of four sheep receiving [Formula: see text] pounds of alfalfa hay per day were recorded at environmental temperatures of 15 °C. and −12 °C. The temperature of the drinking water was 20 °C. when the environmental temperature was 15 °C. and variously 0°, 10°, 20°, and 30 °C. during four different periods when the environmental temperature was −12 °C. At both environmental temperatures, the temperature in the rumen was higher than that in the rectum which, in turn, was higher than that in the subcutaneous tissues. The consumption of feed caused a transient increase in the temperature in the rumen and rectum while the consumption of water caused a transient decrease in the temperature in the rumen. A reduction in environmental temperature from 15 °C. to −12 °C. caused decreases in the temperatures in the rumen, rectum, and subcutaneous tissues, and reduced water intake from about 1600 to about 800 milliliters/day. At an environmental temperature of −12 °C., the temperature of the drinking water did not influence the amount of water consumed. It did, however, have an effect on body temperature because the average temperature in the rectum was slightly higher when the drinking water was 0 °C. than when it was 30 °C.

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