scholarly journals Recombinant ob protein reduces feeding and body weight in the ob/ob mouse.

1995 ◽  
Vol 96 (4) ◽  
pp. 2065-2070 ◽  
Author(s):  
D S Weigle ◽  
T R Bukowski ◽  
D C Foster ◽  
S Holderman ◽  
J M Kramer ◽  
...  
Keyword(s):  
1998 ◽  
Vol 275 (1) ◽  
pp. R186-R193 ◽  
Author(s):  
Lisa A. Eckel ◽  
Wolfgang Langhans ◽  
Andrea Kahler ◽  
L. Arthur Campfield ◽  
Françoise J. Smith ◽  
...  

The mechanisms by which OB protein controls food intake and energy balance are unknown. Therefore, we investigated the effects of a novel modified human recombinant OB protein (Mod-OB) on spontaneous feeding patterns, body weight, running wheel activity, and ovarian cycling in female rats. Mod-OB or vehicle was injected (4 mg ⋅ kg−1 ⋅ day−1sc) for 2 ovarian cycles (8 days) using a within-subjects design. Observations were continued for five ovarian cycles after injections; treatments were then reversed. Mod-OB reduced food intake ∼20% from injection day 1 to postinjection day 2. Body weight was reduced from injection day 3 to postinjection day 15 (maximum decrease, 25 ± 4 g, postinjection days 3 and 4). Food intake was reduced due to decreases in nocturnal meal size, which appeared to be superimposed on the normal pattern of spontaneous feeding (i.e., reductions in meal size at estrus). Mod-OB did not significantly affect diurnal food intake or meal patterns, failed to alter wheel running, and did not disrupt the rats’ ovarian cycles. We conclude that chronically administered Mod-OB reduces food intake in female rats by selectively affecting the mechanisms controlling meal size.


1998 ◽  
Vol 274 (1) ◽  
pp. R248-R254 ◽  
Author(s):  
Todd E. Thiele ◽  
Gertjan Van Dijk ◽  
Keith A. Yagaloff ◽  
Stewart L. Fisher ◽  
Michael Schwartz ◽  
...  

Like leptin (OB protein), central infusion of the nonspecific melanocortin agonist MTII reduces food intake for relatively long periods of time (i.e., 12 h; W. Fan, B. A. Boston, R. A. Kesterson, V. J. Hruby, and R. D. Cone, Nature: 385: 165–168, 1997). To test the hypothesis that MTII may influence ingestive behavior via mechanisms similar to those that mediate the effects of leptin, we infused a single dose of MTII into the third ventricle (i3vt) of Long-Evans rats and examined three dependent measures that have been studied following i3vt infusion of leptin: 1) effects on long-term food intake and body weight (48 h), 2) patterns of c-Fos expression in the brain, and 3) conditioned taste aversion learning. Similar to leptin, MTII reduced 48-h food intake (1.0 nmol dose), reduced body weight at 24 and 48 h (0.1 and 1.0 nmol doses, respectively), and induced c-Fos expression in the paraventricular nucleus of the hypothalamus and the central nucleus of the amygdala. In contrast to leptin, MTII was found to produce conditioned taste aversions. These results are consistent with the hypothesis that MTII may influence regulatory behavior via mechanisms similar to those that mediate the effects of leptin.


1998 ◽  
Vol 275 (1) ◽  
pp. R180-R185 ◽  
Author(s):  
Andrea Kahler ◽  
Nori Geary ◽  
Lisa A. Eckel ◽  
L. Arthur Campfield ◽  
Françoise J. Smith ◽  
...  

The potent hypophagic effect of OB protein (OB) is well established, but the mechanism of this effect is largely unknown. We investigated the effects of chronic administration of a novel modified recombinant human OB (Mod-OB) with a prolonged half-life (>48 h) on ad libitum food intake, spontaneous meal patterns, and body weight in 24 adult, male Sprague-Dawley rats (body weight at study onset: 292 g). Single daily subcutaneous injections of Mod-OB (4 mg/kg daily) for 8 consecutive days significantly reduced ad libitum food intake compared with vehicle injections from injection day 3through postinjection day 3. Mod-OB-injected rats ate between 4.5 and 7.1 g (or 13–20%) per day less than controls, with the reduction primarily occurring during the dark period. Body weight gain was significantly decreased in response to Mod-OB from injection day 8until postinjection day 4, with a maximum difference of 24 g on postinjection day 3. The reduction of food intake by Mod-OB was mainly due to a 21–34% decrease in nocturnal spontaneous meal size. There was no significant effect of Mod-OB on nocturnal meal frequency or duration. Mod-OB also did not reliably affect the size, duration, or frequency of diurnal meals. Mod-OB-injected rats displayed no compensatory hyperphagia after the injection period. These results indicate that chronically administered OB selectively affects the mechanisms controlling meal size in male rats.


Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).


Author(s):  
Julio H. Garcia ◽  
Janice P. Van Zandt

Repeated administration of methyl alcohol to Rhesus monkeys (Maccaca mulata) by intragastric tube resulted in ultrastructural abnormalities of hepatocytes, which persisted in one animal twelve weeks after discontinuation of the methyl alcohol regime. With dosages ranging between 3.0 to 6.0 gms. of methanol per kg. of body weight, the serum levels attained within a few hours averaged approximately 475 mg. per cent.


Author(s):  
R.P. Nayyar ◽  
C.F. Lange ◽  
J. L. Borke

Streptococcal cell membrane (SCM) antiserum injected mice show a significant thickening of glomerular basement membrane (GBM) and an increase in mesangial matrix within 4 to 24 hours of antiserum administration (1,2,3). This study was undertaken to evaluate the incorporation of 3H proline into glomerular cells and GBM under normal and anti-SCM induced conditions. Mice were administered, intraperitoneally, 0.1 ml of normal or anti-SCM serum followed by a 10 µC/g body weight injection of 3H proline. Details of the preparation of anti-SCM (Group A type 12 streptococcal pyogenes) and other sera and injection protocol have been described elsewhere (2). After 15 minutes of isotope injection a chase of cold proline was given and animal sacrificed at 20 minutes, 1,2,4,8,24 and 48 hours. One of the removed kidneys was processed for immunofluorescence, light and electron microscopic radioautographic studies; second kidney was used for GBM isolation and aminoacid analysis.


2006 ◽  
Vol 76 (4) ◽  
pp. 208-215 ◽  
Author(s):  
Astrup

The epidemic of both obesity and type 2 diabetes is due to environmental factors, but the individuals developing the conditions possess a strong genetic predisposition. Observational surveys and intervention studies have shown that excess body fatness is the major environmental cause of type 2 diabetes, and that even a minor weight loss can prevent its development in high-risk subjects. Maintenance of a healthy body weight in susceptible individuals requires 45–60 minutes physical activity daily, a fat-reduced diet with plenty of fruit, vegetables, whole grain, and lean meat and dairy products, and moderate consumption of calorie containing beverages. The use of table values to predict the glycemic index of meals is of little – if any – value, and the role of a low-glycemic index diet for body weight control is controversial. The replacement of starchy carbohydrates with protein from lean meat and lean dairy products enhances satiety, and facilitate weight control. It is possible that dairy calcium also promotes weight loss, although the mechanism of action remains unclear. A weight loss of 5–10% can be induced in almost all obese patients providing treatment is offered by a professional team consisting of a physician and dieticians or nurses trained to focus on weight loss and maintenance. Whereas increasing daily physical activity and regular exercise does not significantly effect the rate of weight loss in the induction phase, it plays an important role in the weight maintenance phase due to an impact on daily energy expenditure and also to a direct enhancement of insulin sensitivity.


2014 ◽  
Vol 84 (1-2) ◽  
pp. 5-11 ◽  
Author(s):  
Eun Y. Jung ◽  
Sung C. Jun ◽  
Un J. Chang ◽  
Hyung J. Suh

Previously, we have found that the addition of L-ascorbic acid to chitosan enhanced the reduction in body weight gain in guinea pigs fed a high-fat diet. We hypothesized that the addition of L-ascorbic acid to chitosan would accelerate the reduction of body weight in humans, similar to the animal model. Overweight subjects administered chitosan with or without L-ascorbic acid for 8 weeks, were assigned to three groups: Control group (N = 26, placebo, vehicle only), Chito group (N = 27, 3 g/day chitosan), and Chito-vita group (N = 27, 3 g/day chitosan plus 2 g/day L-ascorbic acid). The body weights and body mass index (BMI) of the Chito and Chito-vita groups decreased significantly (p < 0.05) compared to the Control group. The BMI of the Chito-vita group decreased significantly compared to the Chito group (Chito: -1.0 kg/m2 vs. Chito-vita: -1.6 kg/m2, p < 0.05). The results showed that the chitosan enhanced reduction of body weight and BMI was accentuated by the addition of L-ascorbic acid. The fat mass, percentage body fat, body circumference, and skinfold thickness in the Chito and Chito-vita groups decreased more than the Control group; however, these parameters were not significantly different between the three groups. Chitosan combined with L-ascorbic acid may be useful for controlling body weight.


2006 ◽  
Vol 76 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Yukari Egashira ◽  
Shin Nagaki ◽  
Hiroo Sanada

We investigated the change of tryptophan-niacin metabolism in rats with puromycin aminonucleoside PAN-induced nephrosis, the mechanisms responsible for their change of urinary excretion of nicotinamide and its metabolites, and the role of the kidney in tryptophan-niacin conversion. PAN-treated rats were intraperitoneally injected once with a 1.0% (w/v) solution of PAN at a dose of 100 mg/kg body weight. The collection of 24-hour urine was conducted 8 days after PAN injection. Daily urinary excretion of nicotinamide and its metabolites, liver and blood NAD, and key enzyme activities of tryptophan-niacin metabolism were determined. In PAN-treated rats, the sum of urinary excretion of nicotinamide and its metabolites was significantly lower compared with controls. The kidneyα-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) activity in the PAN-treated group was significantly decreased by 50%, compared with the control group. Although kidney ACMSD activity was reduced, the conversion of tryptophan to niacin tended to be lower in the PAN-treated rats. A decrease in urinary excretion of niacin and the conversion of tryptophan to niacin in nephrotic rats may contribute to a low level of blood tryptophan. The role of kidney ACMSD activity may be minimal concerning tryptophan-niacin conversion under this experimental condition.


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