The Effects of Anorexic Doses of dextro-Amphetamine on the Ventromedial-Hypothalamic Hyperphagic Rat

1973 ◽  
Vol 51 (5) ◽  
pp. 354-359 ◽  
Author(s):  
Thomas B. Wishart ◽  
Elwood K. Walls

Rats were made hyperphagic by the production of electrolytic lesions in the ventromedial hypothalamus. Following a recovery period during which a rapid weight gain was observed, d-amphetamine was administered intraperitoneally in various dosages, and food intakes, water intakes, and body weight changes were measured after a 3 h feeding period. A dosage of 0.2 mg/kg d-amphetamine had no observable effect. Increasing the dosage to 0.5 or 1.0 mg/kg, however, significantly depressed food and water intakes, and resulted in reduced weight gains in control and experimental animals. Furthermore, the dose–response curves for both experimental and control groups were similar, indicating that d-amphetamine has the same effect in the hyperphagic rat as in the control. It is concluded that amphetamine anorexia is not mediated by the ventromedial hypothalamus.

1952 ◽  
Vol 30 (1) ◽  
pp. 36-41
Author(s):  
William F. Perry

The effect on the rat adrenal gland of massive doses of propylthiouracil over a three-week period has been studied. Care was taken to have any body weight changes of the treated animals paralleled by similar changes in the control, animals. Under these circumstances it was found that on a gland weight basis no atrophy of the adrenal glands occurred. There were however alterations in the adrenal cholesterol and ascorbic acid concentrations, there being an increase in the former and a decrease in the latter and further these changes were not dependent upon any hypometabolism induced by the thiouracil. The level of the adrenal cholesterol and ascorbic acid concentrations measured three hours after injection of ACTH and of epinephrine indicated that the adrenal cortex was responsive to its trophic hormone and that the pituitary–adrenal axis was intact, the degree of response being similar in both treated and control animals.


1975 ◽  
Vol 79 (1) ◽  
pp. 34-42 ◽  
Author(s):  
P. Weisweiler ◽  
P. Schwandt

ABSTRACT In vitro lipolysis was stimulated by porcine pituitary peptides A and B in the rabbit, rat, mouse, and guinea pig. The minimal effective doses were calculated from log dose response curves for free fatty acids and free glycerol liberation. The rabbit was most sensitive responding to 0.008 μg/ml (1.4 pm/ml) peptide A and 0.06 μg/ml (5.3 pm/ml) peptide B respectively. Minipig adipose tissue showed no reaction up to a peptide concentration of 100 μg/ml. After intravenous injection of either peptide at the concentration of 50 μg/kg, FFA and free glycerol increased rapidly in the rabbit with maximal concentrations at 30 min, returning to near normal concentrations after 240 min. Blood glucose concentrations increased continuously in spite of hyperinsulinaemia with a peak concentration at 60 min and complete normalisation after 2 h. Hypertriglyceridaemia and hypocalcaemia were observed in both lipotrophin and control groups. Furthermore, the saline injected rabbits also displayed a slight increase of glucose, FFA, and free glycerol plasma concentrations towards the end of the experiments, suggesting stress stimulated lipolysis. The insulinotrophic effect of both peptides was verified by the fact that injection of lipid emulsion plus heparin led to a comparable increase in FFA and glucose, but to no change in insulin concentrations.


1987 ◽  
Vol 253 (3) ◽  
pp. R523-R529 ◽  
Author(s):  
M. Fukushima ◽  
K. Tokunaga ◽  
J. Lupien ◽  
J. W. Kemnitz ◽  
G. A. Bray

The effect of electrolytic lesions in the ventromedial hypothalamus (VMH) and the paraventricular nucleus (PVN) has been compared during both the dynamic and static phase of weight gain. Hyperphagia and weight gain were greater in the VMH-lesioned rats than in the PVN-lesioned rats. Food intake increased at night after both lesions but increased in the daytime only in VMH-lesioned rats. During the dynamic phase of rapid weight gain, the diurnal pattern of corticosterone was blunted to a similar degree in both lesioned groups. The morning insulin concentrations were higher in both lesioned groups than in the sham-operated controls, but in the static phase only the VMH-lesioned rats had higher insulin levels. In the afternoon the insulin was higher in the VMH-lesioned rats than in either the sham-operated or PVN-lesioned rats. In the dynamic phase the weight of interscapular brown adipose tissue was significantly increased in the VMH-lesioned rats, but the specific GDP binding was depressed both in the morning and afternoon when compared with either the sham-operated or PVN-lesioned groups. In both the dynamic and static phases GDP binding was similar in sham-operated and PVN-lesioned animals. The differences in concentration of corticosterone in morning and afternoon were smaller in the lesioned groups than in the controls. These data are consistent with the hypothesis that animals with PVN lesions do not show the disturbances in food intake or in the autonomic nervous system that characterize the VMH-lesioned rats.


1991 ◽  
Vol 70 (2) ◽  
pp. 590-593 ◽  
Author(s):  
Y. Honda ◽  
I. Hashizume

Steady-state CO2-ventilation response curves with hyperoxia (end-tidal PO2 greater than 200 Torr) and mild hypoxia (end-tidal PO2 approximately equal to 60 Torr) were compared in five carotid body-resected (BR) patients and five control patients. The data were analyzed by fitting a linear equation, V = S(PETCO2-B), where V is minute ventilation S is the response curve slope. PETCO2 is end-tidal PCO2, and B is the response curve threshold. S slightly increased from hyperoxia to hypoxia in both BR and control groups. On the other hand, B moderately increased with hypoxia in BR patients, whereas it slightly decreased in controls. These changes were all not significant. However, in accordance with the change in B, the response curve to hypoxia at V of 10 1/min was significantly shifted in opposite directions in the two groups, i.e., rightward and leftward shift in BR and control groups, respectively. Thus the average magnitude of V calculated at PETCO2 of 40 Torr in hypoxia was significantly lower in BR patients than in controls (P less than 0.01). We conclude that this hypoxic depression of the CO2-ventilation response found in BR patients may have resulted, at least in part, from modulation of the brain stem neural mechanisms that were elicited by loss of afferent discharges from the carotid body.


2002 ◽  
Vol 103 (s2002) ◽  
pp. 124S-127S ◽  
Author(s):  
Katherine E. WILEY ◽  
Anthony P. DAVENPORT

The effect of previous nitrate therapy on vascular responses to endothelin-1 (ET-1) and NO was investigated in human internal mammary artery (IMA) in vitro. Cumulative concentration–response curves to ET-1 were constructed in rings of IMA and the data grouped into IMA from patients given nitrates prior to the bypass graft operation (nitrate group) and IMA from patients who were not prescribed nitrates (control group). No significant differences were observed between the two groups, either in EC50 value [P>0.05; 3.5nM (2.4–5.3nM; 95% confidence interval) and 4.8 (2.2–10nM), nitrate and control groups respectively] or Emax (P>0.05; 78±7.5% and 85±9.5%, nitrate and control group respectively). No significant differences in concentration–response curves to the NO-donor diethylamine NONOate (DEA/NO) in rings of IMA pre-constricted with 10nM ET-1 were observed between control and nitrate groups [P>0.05; EC50 values 0.59 (0.21–1.7) µM and 0.17 (0.03–0.87) µM; Emax 110±5.7% and 112±4.5%, nitrate and control groups respectively]. Concentration–response curves to DEA/NO constructed in normal coronary artery were not significantly different from those in coronary artery obtained from patients with ischaemic heart disease (IHD) [P>0.05; Emax 124±11% and 138±20%; EC50 0.08 (0.02–0.30) µM and 0.23 (0.02–24) µM, normal and IHD respectively]. These data indicate that nitrate therapy does not induce long-term changes in the ET signalling pathway. Furthermore, the tolerance to nitrate therapy is likely to be because of impaired bio-transformation of the drug rather than reduced sensitivity of the media to NO. The similar responses to DEA/NO in normal and atherosclerotic coronary artery suggests that the reduced vasodilator responses in IHD is because of a dysfunctional endothelium and is not mediated by changes in the NO signalling pathway of the smooth muscle.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sima Jilanchi ◽  
Mehdi Nematbakhsh ◽  
Mehrnoosh Bahadorani ◽  
Ardeshir Talebi ◽  
Fatemeh Eshraghi-Jazi ◽  
...  

Background. The role of gender for nephroprotectant agent such as vitamin E in cisplatin- (CP-) induced nephrotoxicity has not been documented yet. Methods. One group from each gender of Wistar rats received a single dose of CP (7 mg/kg; i.p) and was treated with vitamin E (1 g/kg/day) for 7 days, and they were compared with similar gender in the control group. Results. The serum levels of blood urea nitrogen (BUN) and creatinine (Cr) in male animals treated with CP was not different from the control group, but it was significantly different in the female rats (P<0.05). The CP-induced damage intensity in male kidney tissue was not significantly different between the CP-treated and control groups, but this was not the case in female, indicating that the tissue damage in female is significantly different from the control group (P<0.05). No significant difference in serum levels of magnesium (Mg), nitrite, malondialdehyde (MDA), and lactate dehydrogenase (LDH) was seen between the genders. Kidney weight and body weight changes were statistically significant in both genders (P<0.05). Significant difference was observed in uterus weight between the two groups of female (P<0.05). Conclusion. Vitamin E may prevent CP-induced nephrotoxicity in male, but possibly it has not such nephroprotectant effect in female.


2010 ◽  
Vol 80 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Pei-Min Chao ◽  
Wan-Hsuan Chen ◽  
Chun-Huei Liao ◽  
Huey-Mei Shaw

Conjugated linoleic acid (CLA) is a collective term for the positional and geometric isomers of a conjugated diene of linoleic acid (C18:2, n-6). The aims of the present study were to evaluate whether levels of hepatic α-tocopherol, α-tocopherol transfer protein (α-TTP), and antioxidant enzymes in mice were affected by a CLA-supplemented diet. C57BL/6 J mice were divided into the CLA and control groups, which were fed, respectively, a 5 % fat diet with or without 1 g/100 g of CLA (1:1 mixture of cis-9, trans-11 and trans-10, cis-12) for four weeks. α-Tocopherol levels in plasma and liver were significantly higher in the CLA group than in the control group. Liver α-TTP levels were also significantly increased in the CLA group, the α-TTP/β-actin ratio being 2.5-fold higher than that in control mice (p<0.01). Thiobarbituric acid-reactive substances were significantly decreased in the CLA group (p<0.01). There were no significant differences between the two groups in levels of three antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). The accumulation of liver α-tocopherol seen with the CLA diet can be attributed to the antioxidant potential of CLA and the ability of α-TTP induction. The lack of changes in antioxidant enzyme protein levels and the reduced lipid peroxidation in the liver of CLA mice are due to α-tocopherol accumulation.


2020 ◽  
pp. 75-81
Author(s):  
Svetlana Alexandrovna Kosareva ◽  

The paper describes the method for increasing the level of self-organisation in students which has been developed by the author. It also contains the method testing results and presents the prospects and risks teachers could face while applying the method in a higher education institution. The purpose of this study is to find out the prospects and risks of applying the method for increasing the level of self-organisation in students and to determine the ways of reducing the risks. Methodology. The author points out the learning approaches which were the basis of developing the method and describes diagnostic methods for determining students’ self-organisation levels. The work focused on increasing each student’s initial level consists of a theoretical and a practical part and includes project activities on creating a study guide. The results of the study. The method developed proved to be effective. It was established by diagnosing the final level of self-organisation in students in the experimental and control groups. The paper considers the advantages of the method among which there is universal character, flexibility, improvements to teacher’s and students’ professional competence, etc. At the same time it is necessary to be aware of the risks due to the increased amount of teacher’s work and the fact that students’ work within the project tends to be monotonous. In conclusion, the prospects of the method for increasing the level of self-organisation in students are related to its advantages and the final results of the work. The risks of its use can be reduced with the help of the measures proposed in the paper.


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