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 ◽  
...  

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.

2020 ◽  
Vol 64 (2) ◽  
pp. 83-87 ◽  
Author(s):  
Valery N. Rakitskii ◽  
E.G. Chkhvirkiya ◽  
T.M. Epishina

Introduction. Technical products that are part of pesticides recommended for use in agriculture must undergo a comprehensive sanitary and Toxicological examination, which is the basis for preventing the adverse effects of pesticides on the health of workers and the population, as well as on the sanitary state of the environment. Purpose of research - the study of the biological effect of the technical product derived triazolinthionov, with its repeated oral intake in mammals (rats), justification of the permissible daily dose (DSD) for humans. Material and methods. Chronic (12 months) experiment was conducted on male rats with a body weight of 200-210 g tested doses: 5.0; 50.0 and 500.0 mg/kg body weight (1 control and 3 experimental groups and 20 individuals each). In the dynamics of the experiment, we observed the condition and behavior of animals, water and food consumption, fixed the timing of death, recorded changes in body weight, physiological, biochemical and hematological parameters. Results. It was found that the dose of 5.0 mg/kg body weight does not cause significant changes in all studied parameters, doses of 50.0 and 500.0 mg/kg body weight had a polytropic effect on the body of experimental animals. Discussion. The studied technical product at repeated intake in doses of 50,0 and 500,0 mg/kg of body weight causes changes in the state of the Central nervous system of animals (statistically significant changes in SPP, total activity, path length, rest time), as well as changes in carbohydrate, lipid, and lipoprotein metabolism in the body, as evidenced by statistically significant changes in biochemical and hematological indicators. Consequently, doses of 50,0 and 500,0 mg/kg of body weight have a polytropic effect on the body of male rats and are effective. The dose of 5.0 mg/kg of body weight, when administered in animals of the experimental group in comparison with animals of the control group, there are no changes in all the studied parameters throughout the experiment, is accepted as invalid. On the basis of an inactive dose of 5.0 mg/kg of body weight and a reserve factor of 100, we have scientifically justified DSD for humans at the level of 0.05 mg/kg. Conclusion. Studies have shown that long-term repeated oral administration of the studied product into the body of animals (male rats) at a dose of 5.0 mg per 1 kg of body weight does not cause statistically significant changes in all the studied parameters, so the indicated dose is invalid. Doses of 50,0 and 500,0 mg/kg MT have a polytropic effect on the body of male rats and are effective. DSD for humans at the level of 0.05 mg/kg is justified based on the inactive dose at the level of 5.0 mg per 1 kg of body weight, established in a 12-month chronic experiment conducted on male rats, and the reserve coefficient of 100 (taking into account the unexpressed specific and long-term effects).


1973 ◽  
Vol 72 (3) ◽  
pp. 551-568 ◽  
Author(s):  
M. F. Tarttelin ◽  
R. A. Gorski

ABSTRACT The influence of ovarian steroids on food intake (FI), water intake (WI) and body weight (BWt) was measured under various conditions. Ovariectomy results in an increase in FI and BWt, which plateaued around one month after surgery. Daily injection of 1.5 μg oestradiol benzoate (OB) initiated at this time significantly reduced both FI and BWt. This effect of daily OB treatment on FI is only transitory since the FI returns to normal during OB treatment although the effect on BWt is maintained throughout and beyond OB treatment. Following ovariectomy, WI gradually falls, but is returned to normal by daily OB treatment. When oestrogen treatment is initiated at the time of ovariectomy, the increase in FI and BWt is prevented. In additional ovariectomized rats, 3 μg OB was injected every fifth day with either progesterone or oil administered on the intervening days. Although no influence of progesterone injection (either with OB or alone) was detected, the intermittent injection of OB induced cyclic suppression of FI, and the pattern of FI approached that of the intact cycling female. Adaptation to the intermittent injection of OB was not observed. Finally, OB treatment was found to decrease the increased FI seen during pseudopregnancy by a proportion similar to the effect of oestrogen in the long-term ovariectomized animal. These results suggest that oestrogen, but not progesterone, is the ovarian hormone active in the regulation of intake parameters and body weight in the female rat.


1960 ◽  
Vol XXXIII (IV) ◽  
pp. 630-636
Author(s):  
F.-E. Krusius ◽  
P. Peltola

ABSTRACT The study reported here was performed in order to examine the tap water of Helsinki for its alleged goitrogenous effect. In a short-term, 24-hour experiment with rats, kept on an iodine-poor diet, we noticed no inhibition of the 4-hour 131I uptake, as compared with that of animals receiving physiological saline instead of tap water. Two similar groups of rats receiving 1 and 2 mg of mercazole in redistilled water showed a distinct blockage of the 4-hour uptake, which proved the effect of this substance. In a long-term experiment of 5 weeks' duration there was no detectable difference in the body weight, thyroid weight and the 4-hour 131I uptake when the rats receiving tap water or distilled water to which 0.45 per cent of sodium chloride was added were compared with each other. Replacement of tap water by a 10 mg per cent solution of mercazole in redistilled water enlarged the thyroid to double its normal weight and increased the 131I uptake to approximately five times that of the controls. Thus our experiments failed to demonstrate any goitrogenous effect in the tap water of Helsinki. Changes similar to those produced by a long-term administration of mercazole, i. e. an enlargement of the thyroid and an increased thyroidal iodine uptake, have been shown to be due to milk collected from goitrous areas. The observations here reported confirm the importance of milk in the genesis of the goitre endemia of Helsinki. Attention is further called to the fact that a thyroidal enlargement combined with an increased thyroidal iodine uptake cannot always be taken as a sign of iodine deficiency because similar changes may be produced by the administration of goitrogens.


2016 ◽  
Vol 5 (06) ◽  
pp. 4641 ◽  
Author(s):  
Adel Abdel Moneim* ◽  
Sanaa M. Abd El-Twab ◽  
Mohamed B. Ashour ◽  
Ahmed I. Yousef

The goal of diabetes treatment is primarily to save life and alleviate symptoms and secondary to prevent long-term diabetic complications resulting from hyperglycemia. Thus, our present investigation was designed to evaluate the hepato-renal protective effects of gallic acid and p-coumaric acid in nicotinamide/streptozotocin (NA/STZ)-induced diabetic rats. Experimental type 2 diabetes was induced by a single intraperitoneal (i.p.) injection of STZ (65 mg/kg b.wt.), after 15 min of i.p. injection of NA (120 mg/kg b.wt.). Gallic acid and p-coumaric acid were orally administered to diabetic rats at a dose of 20, 40 mg/kg b.wt./day, respectively, for 6 weeks. Body weight, serum glucose, protein profile, liver function enzymes and kidney function indicators was assayed. Treatment with either gallic acid or p-coumaric acid significantly ameliorated the elevated levels of glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea and uric acid. Both compounds were also found to restore total protein, albumin, and globulin as well as body weight of diabetic rats to near normal values. It can conclude that both gallic acid and p-coumaric acid have potent hypoglycemic and hepato-renal protective effects in diabetic rats. Therefore, our results suggest promising hypoglycemic agents that can attenuate the progression of diabetic hepatopathy and nephropathy.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Tai-Yuan Chuang ◽  
Chia-Ying Lien ◽  
Chih-Hsiang Hsu ◽  
Chen-Wen Lu ◽  
Chung-Hsin Wu

Hypothyroidism frequently causes cardiopulmonary dysfunction, such as heart failure and respiratory and metabolic deficiencies. This study investigated the effects of Chinese herbal formula B307 on thyroidectomy-induced cardiopulmonary exercise dysfunction in rats. Twenty male rats were equally divided into four groups: negative control with sham treatment, positive control with oral B307 treatment only, thyroidectomy treatment only, and thyroidectomy with B307 posttreatment groups. The feeding dose of B307 was 50 mg/kg per day for 14 days. We examined and then compared the thyroid-stimulating hormone (TSH), free triiodothyronine (T3), free thyroxine (T4), and reactive oxygen species (ROS) from the blood of these four groups. Also, we compared the body weight, neck subcutaneous blood flow, cardiac ejection function, cardiopulmonary exercise function of oxygen consumption (VO2), carbon dioxide production (VCO2), and respiratory quotient (RQ = VCO2/VO2) among the four groups. Our results indicated that thyroidectomized rats had significantly decreased body weight, neck subcutaneous blood flow, cardiac ejection function, serum T3 and T4, and VO2 and VCO2, but had significantly increased ROS and TSH levels and RQ values compared with sham rats (P<0.01–0.05). In addition, thyroidectomized rats receiving oral B307 treatment had significantly increased body weight, neck subcutaneous blood flow, cardiac ejection function, and VO2, but significantly decreased ROS and TSH levels and VCO2 and RQ values compared with thyroidectomized rats (P<0.01–0.05). We suggest that the B307 could be a protective and beneficial alternative treatment for thyroidectomy-induced cardiopulmonary exercise dysfunction.


1993 ◽  
Vol 182 (1) ◽  
pp. 57-69 ◽  
Author(s):  
M. Wortmann ◽  
W. Zarnack

1. We simultaneously recorded lift/body weight, flight speed, body angle and 12 variables of wing movement for locusts performing tethered long-term flight with low movement scatter. The movements of the forewings and hindwings were recorded in three dimensions by means of miniature induction coils. 2. By adjusting the body angle, we could reproducibly manipulate lift generation as a consequence of induced changes in the wings' movement patterns. We were therefore able to analyse various relationships between the movement patterns and lift. 3. The most prominent variations of kinematic variables were observed for the forewing movements. The relative lift and the steady angle of pitch were positively correlated but there was a negative correlation between relative lift and pitching amplitude. We found no correlation between relative lift and flapping amplitude. Our results seem to correspond to a new theory about unsteady aerodynamics of oscillating aerofoils. 4. We sometimes observed variations in lagging. 5. The forewing downstroke was delayed by 0–8 ms following the hindwing downstroke. Relative lift was positively correlated to this delay.


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