EFFECT OF METHYLPHENIDATE ON SPONTANEOUS ACTIVITY, FOOD INTAKE, AND COLD TOLERANCE OF PROPYLTHIOURACIL-TREATED RATS

1964 ◽  
Vol 42 (4) ◽  
pp. 415-429 ◽  
Author(s):  
Melvin J. Fregly ◽  
Bruce A. Black
Keyword(s):  
Body Weight ◽  
Locomotor Activity ◽  
Food Intake ◽  
Spontaneous Activity ◽  
Cold Tolerance ◽  
Cold Exposure ◽  
Activity Level ◽  
Ambient Temperatures ◽  
And Control ◽  
Dose Levels

Dietary administration of methylphenidate to rats increases locomotor activity (tilt cage method) roughly in proportion to the logarithm of the dose ingested. The results suggest that a dose of 62 mg methylphenidate/kg body wt. per day increases activity level by 50%. At higher dose levels, a tolerance appears to develop and is characterized by high initial levels of activity (days 1 to 3) followed by reduction of activity to a new stable level (days 4 to 6). Methylphenidate increases activity level and decreases food intake and body weight of both hypothyroid (propylthiouracil-treated) and control rats subjected to ambient temperatures of 10, 15, 20, and 28 °C. It fails to increase the tolerance of hypothyroid rats either to chronic (10 and 15 °C) or to acute (5 °C) cold exposure.

Protein appetite is increased after central leptin-induced fat depletion

2007 ◽  
Vol 293 (4) ◽  
pp. R1468-R1473 ◽  
Author(s):  
Michael F. Wiater ◽  
Bryan D. Hudson ◽  
Yvette Virgin ◽  
Sue Ritter
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Body Fat ◽  
Caloric Intake ◽  
Sprague Dawley ◽  
Body Protein ◽  
Macronutrient Selection ◽  
Daily Diet ◽  
Nadir Point ◽  
And Control

Leptin reduces body fat selectively, sparing body protein. Accordingly, during chronic leptin administration, food intake is suppressed, and body weight is reduced until body fat is depleted. Body weight then stabilizes at this fat-depleted nadir, while food intake returns to normal caloric levels, presumably in defense of energy and nutritional homeostasis. This model of leptin treatment offers the opportunity to examine controls of food intake that are independent of leptin's actions, and provides a window for examining the nature of feeding controls in a “fatless” animal. Here we evaluate macronutrient selection during this fat-depleted phase of leptin treatment. Adult, male Sprague-Dawley rats were maintained on standard pelleted rodent chow and given daily lateral ventricular injections of leptin or vehicle solution until body weight reached the nadir point and food intake returned to normal levels. Injections were then continued for 8 days, during which rats self-selected their daily diet from separate sources of carbohydrate, protein, and fat. Macronutrient choice differed profoundly in leptin and control rats. Leptin rats exhibited a dramatic increase in protein intake, whereas controls exhibited a strong carbohydrate preference. Fat intake did not differ between groups at any time during the 8-day test. Despite these dramatic differences in macronutrient selection, total daily caloric intake did not differ between groups except on day 2. Thus controls of food intake related to ongoing metabolic and nutritional requirements may supersede the negative feedback signals related to body fat stores.

Effect of Changes in Ambient Temperature on Spontaneous Activity, Food Intake and Body Weight of Goldthioglucose-Obese and Nonobese Mice

1957 ◽  
Vol 188 (3) ◽  
pp. 435-438 ◽  
Author(s):  
M. J. Fregly ◽  
N. B. Marshall ◽  
J. Mayer
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Ambient Temperature ◽  
The Body ◽  
Lower Body ◽  
Obese Mice ◽  
Ambient Temperatures ◽  
Exposure To Cold ◽  
Running Activity ◽  
Body Weights

Goldthioglucose-obese mice cannot adjust their food intake to meet the increased energy requirements due to cold. At all ambient temperatures above 15°C the spontaneous running activity of these animals is less than that observed for nonobese controls. Activity of obese mice is maximal at 19°C and minimal at 15°C or lower. Body weights decrease during exposure to cold. In contrast to that of obese mice, running activity of nonobese controls is maximal at an ambient temperature of 25°C but nearly ceases at 15°C or lower. The food intake of these animals increases in the cold and remains elevated even at temperatures at which activity decreases. The body weight of nonobese controls is either maintained constant or increases during exposure to cold air.

Hypothermia in the Rat, Hamster, Ground Squirrel and Pigeon Following Chlorpromazine

1958 ◽  
Vol 193 (3) ◽  
pp. 547-552 ◽  
Author(s):  
R. A. Hoffman ◽  
M. X. Zarrow
Keyword(s):  
Body Weight ◽  
Body Temperature ◽  
Sex Difference ◽  
Dose Level ◽  
Cold Exposure ◽  
Ground Squirrel ◽  
Mammalian Species ◽  
Rapid Decline ◽  
Temperature Changes ◽  
Dose Levels

Body temperature changes induced by two dose levels of chlorpromazine HCl were compared in the rat, hamster, ground squirrel and pigeon. In addition, the effect of cold exposure was determined in the hamster. All three mammalian species showed a rapid decline in temperature by the first 2 hours following the injection of 10 mg/kg body weight of chlorpromazine, after which a gradual return toward normal was evident. However, a further decrease in body temperature occurred at the higher dose level of chlorpromazine (100 mg/kg body weight) and the degree of hypothermia varied with the species. The hamster appeared to be the most resistant to this compound while the ground squirrel was the least resistant. The female of the three mammalian species was less susceptible than the male. The combination of cold exposure and chlorpromazine in the hamster produced a decline in body temperature that was greater than that produced by either stressor alone. Again a sex difference was noted. The pigeon failed to respond to the drug in any degree comparable to that seen in the mammals. This was thought to be due to the lack of effect on respiration, an important thermoregulatory mechanism in the bird.

scholarly journals Role of SOCS3 in POMC neurons in metabolic and cardiovascular regulation

2019 ◽  
Vol 316 (4) ◽  
pp. R338-R351 ◽  
Author(s):  
Zhen Wang ◽  
Jussara M. do Carmo ◽  
Alexandre A. da Silva ◽  
Kandice C. Bailey ◽  
Nicola Aberdein ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Food Intake ◽  
Stress Test ◽  
Control Diet ◽  
Negative Regulator ◽  
Cytokine Signaling ◽  
Male And Female ◽  
Air Jet ◽  
And Control

Suppressor of cytokine signaling 3 (SOCS3) is a negative regulator of leptin signaling. We previously showed that the chronic effects of leptin on blood pressure (BP) and glucose regulation are mediated by stimulation of proopiomelanocortin (POMC) neurons. In this study we examined the importance of endogenous SOCS3 in POMC neurons in control of metabolic and cardiovascular function and potential sex differences. Male and female SOCS3flox/flox/POMC-Cre mice in which SOCS3 was selectively deleted in POMC neurons and control SOCS3flox/flox mice were studied during a control diet (CD) or a high-fat diet (HFD) and during chronic leptin infusion. Body weight was lower in male and female SOCS3flox/flox/POMC-Cre than control mice fed the CD, despite similar food intake. Male SOCS3flox/flox/POMC-Cre mice exhibited increased energy expenditure. BP and heart rate were similar in male and female SOCS3flox/flox/POMC-Cre and control mice fed the CD. HFD-fed male and female SOCS3flox/flox/POMC-Cre mice showed attenuated weight gain. HFD-induced elevations in baseline BP and BP responses to an air-jet stress test were greater in female SOCS3flox/flox/POMC-Cre than control mice. Chronic leptin infusion produced similar responses for food intake, body weight, oxygen consumption, blood glucose, BP, and heart rate in all groups. Thus SOCS3 deficiency in POMC neurons influences body weight regulation in the setting of CD and HFD and differentially affects BP and energy balance in a sex-specific manner but does not amplify the dietary, glycemic, or cardiovascular effects of leptin.

Cold-specific feeding response of rats to cold exposure and energy density of body weight change

1981 ◽  
Vol 51 (2) ◽  
pp. 327-334 ◽  
Author(s):  
S. D. Morrison
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Density ◽  
Heat Flow ◽  
Cold Exposure ◽  
Weight Change ◽  
Flow Model ◽  
Energy Yield ◽  
Body Weight Change ◽  
Heat Flow Model

The increased food intake of rats exposed to cold is the result of increased intake due to cold (cold-specific compartment; A) and decreased intake due to simultaneously decreased body weight (weight-specific compartment; B). The two compartments are evaluated at 5, 13, and 17 degrees C. B is evaluated as the food intake of theoretical, isogravimetric control (identical to cold-exposed rats with respect to body weight and rate of change of body weight and identical to nonexposed rats in all other respects) that takes into account both the change in energy expenditure due to decreased body weight and the energy yield from tissue catabolism represented by change of body weight. A is the observed food intake minus B. A theoretical heat-flow model, in which expected changes in heat flow during cold exposure drive food intake to maintain or restore preexposure body weight status, corroborated the partition derived from experimental data. However, both the experimental results and the heat-flow model imply that the energy density of body weight change is negatively correlated with rate of body weight change. The energy density of weight change is high with high rates of weight loss and low with high rats of weight gain.

Energy cost, fluid and electrolyte balance in subarctic survival situations

1964 ◽  
Vol 19 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Terence A. Rogers ◽  
James A. Setliff ◽  
John C. Klopping
Keyword(s):  
Body Weight ◽  
Cold Exposure ◽  
Technical Assistance ◽  
Urine Volume ◽  
Extracellular Fluid ◽  
Electrolyte Balance ◽  
Acid Base Balance ◽  
Ambient Temperatures ◽  
Base Balance ◽  
The Cost

In two experiments a total of 12 men were subjected to 5 days of starvation under survival conditions in the winter subarctic. They wore flying clothing rated at 3.5 clo. The caloric cost, as calculated from oxygen consumption, was 2,300 kcal/m2 for the first day and 2,000 kcal/m2 for subsequent days at ambient temperatures of -30 C. At -10 C the cost of subsequent days fell to 1,500 kcal/m2. The subjects lost 8% of body weight but regained 5% body weight after 5 days refeeding on a barely maintenance diet. One-third of the original (8%) weight loss was due to an isotonic contraction of extracellular fluid. Changes in heart rate, pulse pressure, and hematocrit consistent with this fluid contraction were observed. Although the water intake did not exceed the 5-day urine volume (5 liters), the subjects did not experience thirst until after return to the warm. Note:(With the Technical Assistance of William P. Esser and Kermitt R. Skrettingland) caloric cost; cold exposure; electrolyte balance in starvation; fasting; fluid balance in starvation; IMP, integrating motor pneumotachograph; fat carbohydrate and protein catabolism in cold exposure and starvation; cold diuresis; sodium, potassium and acid-base balance in acute starvation Submitted on June 3, 1963

scholarly journals Development of obesity in transgenic rats with low circulating growth hormone levels: involvement of leptin resistance

2000 ◽  
pp. 535-541 ◽  
Author(s):  
Y Furuhata ◽  
R Kagaya ◽  
K Hirabayashi ◽  
A Ikeda ◽  
KT Chang ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Cerebrospinal Fluid ◽  
Body Weight ◽  
Weight Gain ◽  
Locomotor Activity ◽  
Food Intake ◽  
Body Weight Gain ◽  
Leptin Resistance ◽  
Intracerebroventricular Injection ◽  
Transgenic Rats

BACKGROUND: Human growth hormone (hGH) transgenic (TG) rats have been produced in our laboratory. These TG rats are characterized by low circulating hGH levels, virtually no endogenous rGH secretion, and massive obesity. OBJECTIVE: To elucidate how energy balance and leptin sensitivity contributed to the establishment of this obesity. DESIGN AND METHODS: Food intake, locomotor activity and leptin concentrations in serum and cerebrospinal fluid were measured in TG rats and their non-transgenic littermates (control). The effect of intraperitoneal and intracerebroventricular injection of leptin on food intake and body weight gain was also examined. RESULTS: An increase in food intake and a decrease in locomotor activity were observed from 4 and 7 weeks of age, respectively, in the transgenic rats compared with control. Serum leptin concentrations of the transgenic rats were more than twice as high as those of control rats and were associated with an increased white adipose tissue mass and ob gene expression. Intraperitoneal injection of leptin significantly decreased food intake and body weight gain in control rats, but not in transgenic rats. Leptin concentration in the cerebrospinal fluid of transgenic rats was not different from that of control rats, and intracerebroventricular injection of leptin was similarly effective in reducing food intake and body weight gain as it was in control rats. CONCLUSIONS: These results suggest that the transgenic rats, whose GH secretion is suppressed, develop obesity due to early onset of an increase in food intake and a decrease in locomotor activity with leptin resistance resulting from deteriorating leptin transport from peripheral blood to cerebrospinal fluid.

scholarly journals Comparative effects of continuous infusion of m CPP, Ro 60-0175 and d -fenfluramine on food intake, water intake, body weight and locomotor activity in rats

2000 ◽  
Vol 130 (6) ◽  
pp. 1305-1314 ◽  
Author(s):  
S P Vickers ◽  
K R Benwell ◽  
R H Porter ◽  
M J Bickerdike ◽  
G A Kennett ◽  
...  
Keyword(s):  
Body Weight ◽  
Locomotor Activity ◽  
Food Intake ◽  
Continuous Infusion ◽  
Water Intake ◽  
Intake Water
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