Changes in core temperature and feeding in rats by levorphanol and dextrorphan

1979 ◽  
Vol 57 (9) ◽  
pp. 1028-1032 ◽  
Author(s):  
J. A. Thornhill ◽  
M. Hirst ◽  
C. W. Gowdey
Keyword(s):  
Food Intake ◽  
Feeding Activity ◽  
Control Period ◽  
Saline Control ◽  
Sprague Dawley ◽  
Continuous Reinforcement Schedule ◽  
Continuous Reinforcement ◽  
Subcutaneous Injections ◽  
Daily Food ◽  
Sprague Dawley Rats

Male Sprague–Dawley rats received saline for 5 days before and 5 days after daily subcutaneous injections of levorphanol or dextrorphan tartrate (8 mg base/kg) for 10 days. Core temperatures, measured by telemetry, and acquisition of food pellets on a continuous reinforcement schedule were monitored simultaneously and recorded every 30 min for each rat throughout the experiment. After the first levorphanol injections signs of acute intoxication were apparent, and a mild but delayed hyperthermia was observed and food intake declined. With repeated injections of levorphanol peak hyperthermia increased and occurred with a shorter latency after administration, as did a phase of 'stimulated' feeding activity. This phase of vigorous feeding during light hours markedly disrupted the characteristic diurnal pattern of daily food intake. During withdrawal temperatures decreased, feeding became more intermittent, and signs of increased irritability were evident in the levorphanol group. Patterns during daily injections of dextrorphan, and after its withdrawal, were similar to those in the saline control period. These results indicate that the patterns of change in temperature and feeding responses to levorphanol are similar to those found earlier with heroin, codeine, and morphine, and that these changes involve stereospecific receptors.

scholarly journals Loss of leptin receptor-expressing cells in the hindbrain decreases forebrain leptin sensitivity

2020 ◽  
Vol 318 (5) ◽  
pp. E806-E816
Author(s):  
Ruth B. S. Harris
Keyword(s):  
Food Intake ◽  
Leptin Receptor ◽  
Third Ventricle ◽  
Sprague Dawley ◽  
Medial Nucleus ◽  
Leptin Sensitivity ◽  
Daily Food ◽  
Sprague Dawley Rats ◽  
Integrated Response ◽  
Transcription 3

Previous studies indicate that inhibition of food intake by leptin is mediated by an integrated response to activation of hypothalamic and hindbrain receptors. This study tested whether loss of hindbrain leptin receptor signaling changed sensitivity to forebrain leptin. Injections of leptin-conjugated saporin (Lep-Sap) into the medial nucleus of the solitary tract (NTS) were used to destroy hindbrain leptin receptor-expressing neurons of male Sprague–Dawley rats. Controls were injected with saporin conjugated with a nonsense peptide (Blk-Sap). Lep-Sap had no effect on daily food intake or body weight, but expression of phosphorylated signal transducer and activator of transcription 3 (pSTAT3) in the NTS following a peripheral injection of leptin was abolished 26 days after Lep-Sap injections. To test forebrain leptin sensitivity, Lep-Sap and Blk-Sap rats received third-ventricle injections of 0, 0.05, 0.1, 0.25, or 0.5 μg leptin. Food intake was inhibited by 0.25 and 0.5 μg leptin in Blk-Sap rats, but there was no significant effect of leptin on food intake of Lep-Sap rats. There was no difference in hypothalamic pSTAT3 in unstimulated conditions, but pSTAT3 was lower in the dorsomedial region of the ventromedial nucleus of the hypothalamus (VMH) of Lep-Sap rats compared with Blk-Sap rats following a third-ventricle injection of 0.25 μg leptin. These results are consistent with previous data showing that loss of VMH leptin receptor-expressing cells prevents weight loss caused by fourth-ventricle leptin infusion and show that the integrated response between the hindbrain and forebrain is heavily dependent on leptin activity in the VMH.

Effects of repeated isocaloric macronutrient loads on daily food intake of rats

1984 ◽  
Vol 247 (2) ◽  
pp. R387-R392 ◽  
Author(s):  
A. Geliebter ◽  
J. T. Liang ◽  
T. B. Van Itallie
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Corn Oil ◽  
Medium Chain Triglyceride ◽  
Repeated Administration ◽  
Sprague Dawley ◽  
Water Load ◽  
Daily Food ◽  
Sprague Dawley Rats

The effects of repeated administration of different macronutrient loads on spontaneous food intake and body weight of male Sprague-Dawley rats were studied. For 6 wk, eight groups of five rats each received two daily intragastric loads, 3.5 h apart, consisting of isocaloric amounts of one of the following: albumin, sucrose, cornstarch, corn oil, a mixture of the preceding four loads, butter, medium-chain triglyceride, or a noncaloric load of water. Spontaneous intakes of rat chow were measured 3.5 and 24 h after the first daily load. All the macronutrient loads depressed subsequent 3.5-h intakes more than the water load (P less than 0.01), and protein loads depressed 3.5-h intakes the most (P less than 0.01). The macronutrient loads also depressed 24-h intakes more than water loads (P less than 0.01) but did not differ among themselves. The mixture load depressed 3.5- and 24-h food intakes by an amount comparable with the average effects of its component loads. Neither body weight nor body fat as measured by the Lee index differed among the groups after 6 wk. The results indicate that fairly accurate long-term regulation of spontaneous energy intake occurs regardless of the type of macronutrient in the load.

BIOASSAY OF GROWTH HORMONE

1974 ◽  
Vol 75 (4) ◽  
pp. 669-682 ◽  
Author(s):  
K.-G. Thorngren ◽  
L. I. Hansson
Keyword(s):  
Growth Hormone ◽  
Bone Growth ◽  
Control Period ◽  
Growth Stimulation ◽  
Sprague Dawley ◽  
Hormone Administration ◽  
Sprague Dawley Rats ◽  
Hypophysectomized Rats ◽  
Operative Control ◽  
Sensitivity Specificity

ABSTRACT The growth stimulating effect of growth hormone was determined with tetracycline as intravital marker of the longitudinal bone growth of proximal tibia in female Sprague-Dawley rats hypophysectomized at 60 days of age. After a post-operative control period of 15 days growth hormone (NIH-GH-B16) was given daily for 5 or 10 days followed by a 10 day period after its withdrawal. L-thyroxine was given in association with the growth hormone administration to potentiate the growth stimulation. A linear log dose-response relation was found for the two administration models with a high precision. The thyroxine-treatment increased the sensitivity of the bioassay. An administration period of 5 days was found sufficient for the bioassay of growth hormone in thyroxine-treated hypophysectomized rats. Compared with the earlier bioassay methods for growth hormone, the present bioassay is more favourable when all the factors, such as precision, sensitivity, specificity, and administration period are considered.

scholarly journals Mild DOCA-salt hypertension: sympathetic system and role of renal nerves

2011 ◽  
Vol 300 (5) ◽  
pp. H1781-H1787 ◽  
Author(s):  
Sachin S. Kandlikar ◽  
Gregory D. Fink
Keyword(s):  
Control Period ◽  
Whole Body ◽  
Renal Nerves ◽  
Experimental Hypertension ◽  
Sympathetic Activation ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Salt Hypertension ◽  
Hypertension Development

Excess sympathetic nervous system activity (SNA) is linked to human essential and experimental hypertension. To test whether sympathetic activation is associated with a model of deoxycorticosterone acetate (DOCA)-salt hypertension featuring two kidneys and a moderate elevation of blood pressure, we measured whole body norepinephrine (NE) spillover as an index of global SNA. Studies were conducted in chronically catheterized male Sprague-Dawley rats drinking water containing 1% NaCl and 0.2% KCl. After a 7-day surgical recovery and a 3-day control period, a DOCA pellet (50 mg/kg) was implanted subcutaneously in one group of rats (DOCA), while the other group underwent sham implantation (Sham). NE spillover was measured on control day 2 and days 7 and 14 after DOCA administration or sham implantation. During the control period, mean arterial pressure (MAP) was similar in Sham and DOCA rats. MAP was significantly increased in the DOCA group compared with the Sham group after DOCA administration ( day 14: Sham = 109 ± 5.3, DOCA = 128 ± 3.6 mmHg). However, plasma NE concentration, clearance, and spillover were not different in the two groups at any time. To determine whether selective sympathetic activation to the kidneys contributes to hypertension development, additional studies were performed in renal denervated (RDX) and sham-denervated (Sham-DX) rats. MAP, measured by radiotelemetry, was similar in both groups during the control and DOCA treatment periods. In conclusion, global SNA is not increased during the development of mild DOCA-salt hypertension, and fully intact renal nerves are not essential for hypertension development in this model.

scholarly journals CCK-8 and CCK-58 differ in their effects on nocturnal solid meal pattern in undisturbed rats

2012 ◽  
Vol 303 (8) ◽  
pp. R850-R860 ◽  
Author(s):  
Miriam Goebel-Stengel ◽  
Andreas Stengel ◽  
Lixin Wang ◽  
Gordon Ohning ◽  
Yvette Taché ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Food Intake ◽  
Molecular Forms ◽  
Reduce Food Intake ◽  
Dark Phase ◽  
Sprague Dawley ◽  
Solid Meal ◽  
Sprague Dawley Rats ◽  
And Behavior

Various molecular forms of CCK reduce food intake in rats. Although CCK-8 is the most studied form, we reported that CCK-58 is the only detectable endocrine peptide form in rats. We investigated the dark-phase rat chow intake pattern following injection of CCK-8 and CCK-58. Ad libitum-fed male Sprague-Dawley rats were intraperitoneally injected with CCK-8, CCK-58 (0.6, 1.8, and 5.2 nmol/kg), or vehicle. Food intake pattern was assessed during the dark phase using an automated weighing system that allowed continuous undisturbed monitoring of physiological eating behavior. Both CCK-8 and CCK-58 dose dependently reduced 1-h, dark-phase food intake, with an equimolar dose of 1.8 nmol being similarly effective (−49% and −44%). CCK-58 increased the latency to the first meal, whereas CCK-8 did not. The intermeal interval was reduced after CCK-8 (1.8 nmol/kg, −41%) but not after CCK-58. At this dose, CCK-8 increased the satiety ratio by 80% and CCK-58 by 160%, respectively, compared with vehicle. When behavior was assessed manually, CCK-8 reduced locomotor activity (−31%), whereas grooming behavior was increased (+59%). CCK-58 affected neither grooming nor locomotor activity. In conclusion, reduction of food intake by CCK-8 and CCK-58 is achieved by differential modulation of food intake microstructure and behavior. These data highlight the importance of studying the molecular forms of peptides that exist in vivo in tissue and circulation of the animal being studied.

Abstract P607: Nitric Oxide (NO) Regulates Paracellular Permselectivity in Isolated, Perfused Rat Thick Ascending Limbs through Claudin-19

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Casandra M Monzon ◽  
Jeffrey Garvin
Keyword(s):  
Nitric Oxide ◽  
Control Period ◽  
Sprague Dawley ◽  
Permeability Ratio ◽  
Ionic Selectivity ◽  
No Donor ◽  
Sprague Dawley Rats ◽  
Spermine Nonoate ◽  
Dilution Potential ◽  
Cl Permeability

About 50% of the Na reabsorbed in thick ascending limbs (TALs) traverses the paracellular pathway. The ionic selectivity of this route is regulated by claudins in the tight junctions. TALs express claudin-19 which has been reported to regulate TAL Na permeability. We showed that nitric oxide (NO) decreases Na/Cl permeability ratio (PNa/PCl) in TALs by increasing the absolute permeabilities of both ions though PCl increased more. However, whether NO affects paracellular permeability via claudin-19 is unknown. We hypothesize that NO regulates the paracellular permselectivity in TALs through this claudin. To test this we perfused TALs from Sprague Dawley rats and measured dilution potentials (a measure of permselectivity) with and without exogenously-added or endogenously-produced NO in the presence or absence of an antibody against an extracellular domain of claudin-19 or Tamm-Horsfall protein (control). Dilution potentials were generated by reducing bath NaCl from 141 to 32 mM. For the NO donor spermine NONOate (SPM): during the control period, the dilution potential was -9.3 ± 1.8 mV. After SPM (200 μM), it was -6.7 ± 1.6 mV (n = 6; p < 0.003). In the presence of the claudin-19 antibody, SPM had no significant effect on dilution potentials (claudin-19 antibody alone: -12.7 ± 2.1 mV vs claudin-19 antibody + SPM: -12.9 ± 2.4 mV; n = 6). The claudin-19 antibody alone had no effect on dilution potentials. In the presence of the Tamm-Horsfall protein, the effect of SPM was still present (Tamm-Horsfall protein antibody alone: -9.7 ± 1.0 mV; Tamm-Horsfall protein antibody + SPM: -6.3 ± 1.1 mV, p<0.006, n = 6). For experiments with endogenously-produced NO, L-arginine the substrate for NO synthase was added. During the control period, the dilution potential was -11.0 ± 1.1 mV. After L-arginine (500 μM) treatment, they were -9.0 ± 1.2 mV (n = 9; p < 0.05). In the presence of the claudin-19 antibody, L-arginine had no significant effect on dilution potentials (claudin-19 antibody alone: -10.1 ± 0.9 mV vs claudin-19 antibody + L-arginine: -10.1 ± 1.0 mV; n = 9). In the presence of the Tamm-Horsfall protein, the effect of L-arginine was still present. We conclude that the actions of NO on the paracellular permselectivity in thick ascending limbs are at least in part mediated by claudin-19.

Appetite suppressant activity in plasma of rats after intestinal bypass surgery

1982 ◽  
Vol 243 (1) ◽  
pp. R60-R64 ◽  
Author(s):  
R. L. Atkinson ◽  
E. L. Brent
Keyword(s):  
Food Intake ◽  
Polymorphonuclear Leukocytes ◽  
Bypass Surgery ◽  
Aversive Conditioning ◽  
Jejunoileal Bypass ◽  
Intestinal Bypass ◽  
Sprague Dawley ◽  
Appetite Suppressant ◽  
Sprague Dawley Rats ◽  
Subsequent Intake

Male Sprague-Dawley rats with a jejunoileal bypass ate 32% less in the 1st h of refeeding after an overnight fast than did sham-bypass rats. Fasted recipients injected intraperitoneally with 6-7 ml of bypass plasma also ate 32% less (P less than 0.001) during the 1st h of refeeding than did recipients of sham-bypass plasma, but subsequent intake was not significantly different. Rectal temperature, hematocrit, white blood cell count, and percent polymorphonuclear leukocytes were not different between bypass and sham-bypass rats. A test for aversive conditioning suggested that the effect of bypass plasma was not due to illness or discomfort. These data suggest that intestinal bypass produces a transferable humoral factor that suppresses food intake and that the effect is not due to illness or discomfort. If the decreased food intake in humans after intestinal bypass is due to a similar mechanism, the possibility exists that this humoral appetite-suppressant factor may be clinically useful in the treatment of morbid obesity.

scholarly journals Quantitative Analysis of Diffusion Tensor Imaging in Chronic Hepatitis in Rats

2020 ◽  
Author(s):  
Mengping Huang ◽  
Xin Lu ◽  
Xiaofeng Wang ◽  
Jian Shu
Keyword(s):  
Chronic Hepatitis ◽  
Diffusion Tensor Imaging ◽  
Liver Fibrosis ◽  
Diffusion Tensor ◽  
Control Group ◽  
Sprague Dawley ◽  
Subcutaneous Injections ◽  
Sprague Dawley Rats ◽  
Pathological Stages ◽  
The Brain

Abstract Background Diffusion tensor imaging (DTI) is mainly used for detecting white matter fiber in the brain. From this, DTI has been applied to assess fiber in liver disorders by prior studies. But non-sufficient data has been obtained if DTI could be used for exactly staging chronic hepatitis. This study is to assess the value of DTI for staging of liver fibrosis (F), necroinflammatory activity (A), and steatosis (S) of chronic hepatitis in rats. Methods Seventy male Sprague-Dawley rats were divided into control group(n = 10) and experimental group(n = 60). The rat models of chronic hepatitis were established by abdominal subcutaneous injections of 40% CCl4. All rats underwent 3.0T MRI. ROIs were placed on DTI to estimate MR parameters (rADC value and FA value). Histopathology was the reference standard. Multiple linear regression was used to analyze the association between MR parameters and pathology. The differences in rADC value and FA value among pathological stages were evaluated by MANOVA or ANOVA. LSD was used to test the differences between each two groups. ROC analysis was performed. Results The numbers of each pathology were as follows: F0(n = 15), F1(n = 11), F2(n = 6), F3(n = 9), F4(n = 6); A0(n = 8), A1(n = 16), A2(n = 16), A3(n = 7); S0(n = 10), S1(n = 7), S2(n = 3), S3(n = 11), S4(n = 16). The rADC value had a negative correlation with liver fibrosis (r=-0.392, P = 0.008) and inflammation (r=-0.359, P = 0.015). FA value had a positive correlation with fibrosis (r = 0.409, P = 0.005). Significant differences were found in FA value between F4 and F0 ~ F3 (P = 0.03), while no significant differences among F0 ~ F3 were found (P > 0.05). AUC of FA value in differentiating F4 from F0 ~ F3 was 0.909(p < 0.001) with 83.3% Sensitivity, 85.4% specificity when the FA value was at the cut-off of 588.089(× 10− 6mm2/s). Conclusion FA value for DTI can distinguish early cirrhosis from normal, mild and moderate liver fibrosis.

scholarly journals Mechanism of dopamine inhibition of renal phosphate transport.

1992 ◽  
Vol 2 (11) ◽  
pp. 1601-1607
Author(s):  
J Isaac ◽  
R P Glahn ◽  
M M Appel ◽  
M Onsgard ◽  
T P Dousa ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Brush Border Membrane ◽  
Phosphate Transport ◽  
Constant Infusion ◽  
Saline Control ◽  
Control Group ◽  
Sprague Dawley ◽  
Pi Transport ◽  
Sprague Dawley Rats ◽  
Dependent Transport

Dopamine (DA) is natriuretic and phosphaturic. However, whether the effect of DA on Pi reabsorption is a consequence of its effect on sodium transport is not known. Therefore, this study was performed to determine the effect of DA on the maximal transport of phosphate (TmPi), and upon the capacity of renal proximal brush border membrane (BBM) for (Naextra-vesicular greater than Naintravesicular)-gradient-dependent transport of Pi, as compared with the transport of other solutes. Graded infusions of Pi (0, 1, 2, and 3 mumols/min) were given to thyroparathyroidectomized male Sprague-Dawley rats in the presence of vehicle (0.9% NaCl; N = 5), DA 15 micrograms/kg/min; N = 6), or parathyroid hormone ((PTH); 1 U/kg/min; N = 5). The TmPi for rats infused with DA (3.3 +/- 0.3 mumol/mL) was significantly less than the TmPi for saline control rats (4.4 +/- 0.2 mumol/mL). Rats infused with PTH exhibited the lowest TmPi (1.8 +/- 0.3 mumol/mL). No differences in sodium excretion were observed among any of the groups. Na-dependent Pi transport was studied in BBM vesicles (BBMV) prepared from rats fed a low-phosphate diet for 2 days that were anesthetized, acutely thyroparathyroidectomized, and systemically infused with DA (350 micrograms bolus, plus 35 micrograms/kg/min; N = 8), PTH (33 U/kg bolus, followed by a continuous infusion of 1 U/kg/min; N = 6), or vehicle (1 mL/kg bolus, plus 2 mL/h constant infusion of 0.9% NaCl; N = 8) for 90 min. DA significantly inhibited the Na cotransport of Pi by 22.4 +/- 4.1% (P less than 0.01) as compared with the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

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