scholarly journals Bile lipids in rats under chronic social stress

2017 ◽  
Vol 8 (3) ◽  
pp. 356-362
Author(s):  
A. M. Liashevych ◽  
I. I. Tubaltseva ◽  
Y. M. Reshetnik ◽  
O. V. Bondarenko ◽  
S. P. Veselsky ◽  
...  

Our experiments studied changes in lipid compound of bile of non-purebred male rats under the condition of social stress while the preparation “Korvitin” was used against the stress. Using the method of thin-layer chromatography, we determined the concentrations of phospholipids, cholesterol and its esters, free fatty acids and triglycerides in the animals’ bile, which was obtained through vivesection a day and a month after the rats were first subjected to chronic social stress (model of social defeat), and also in the bile of the animals which were treated intragastrically with “Korvitin” against the stress (1 mg/kg, 7 days). In the bile of the male rats which experienced chronic social stress the concentration of free cholesterol decreased and the content of its esters increased both immediately after the initiation of stress and after a month of exposure to stress. The concentration of free fatty acids in the bile decreased after modeling chronic social stress, but increased in liver secretion, taken a month after the animals first experienced stress. In the bile of male rats immediately after the procedure of exposing the animals to stress, the content of phospholipids decreased. Using “Korvitin” during the modeling of social stress caused decrease in the content of phospholipids in the rats’ bile and caused significant increase in the concentration of free fatty acids, triglycerides and cholesterol esters in the liver secretion. The study found significant changes in the concentration of lipids in the bile and in their distribution in the organism of male rats under the conditions of experimentally induced chronic stress. The effect of stress on the bile of rats requires further study for determining its pathogenic role. 

2021 ◽  
Vol 12 (3) ◽  
pp. 419-424
Author(s):  
A. M. Liashevych ◽  
І. S. Lupaina ◽  
T. L. Davydovska ◽  
O. V. Tsymbalyuk ◽  
Y. R. Oksentiuk ◽  
...  

The article looks at recent research dealing with changes in the bile acid composition of the bile of outbred male rats under chronic social stress (social defeat in daily male confrontations, 14 days) when administered Corvitin (1 mg/kg, intragastrically, 7 days). Chronic social stress was created by daily agonistic interactions between animals. The main fractions of conjugated bile acids – taurocholic, taurohenodeoxycholic and taurodeoxycholic, glycocholic, glycochenodeoxycholic and glycodeoxycholic and free ones – cholic, chenodeoxycholic and deoxycholic were determined by the method of thin layer chromatography of bile. The conjugation index (ratio of the sum of conjugated cholates to the sum of free ones) and hydroxylation (ratio of the sum of trihydroxycholanic bile acids to the sum of dihydroxycholanic ones) of bile acids were calculated. The research showed that in the conditions of experimental social stress, Corvitin enhances the conjugation of bile acids with taurine and glycine, i.e. stimulates detoxification processes in hepatocytes. In the conditions of chronic social stress in male rats, the processes that had provided the flow of glycoconjugates of bile acids from hepatocytes to the bile ducts were further suppressed. The concentrations of glycocholic acid and glycochenodeoxycholic and glycodeoxycholic acids in the bile of male intruders were lower than the control values. But, as seen in the experiment, the use of Corvitin normalized these indicators. The experiment showed that in the conditions of chronic social stress, the content of cholic acid in the bile of intruder rats decreased, and when correcting the pathological condition using Corvitin, it reached the control values. The use of Corvitin simultaneously with the simulation of experimental social stress normalized the biliary secretory function of the liver, indicating the high potential of using Corvitin as a corrective factor in chronic social stress. Correction of stress-induced pathologies of liver bile-secretory function by Corvitin requires further thorough experimental studies.


1975 ◽  
Vol 53 (11) ◽  
pp. 1170-1183 ◽  
Author(s):  
W. C. Breckenridge ◽  
A. Kuksis

The molecular specificity in the biosynthesis of diacylglycerols by rat intestinal mucosa was examined by means of radioactive markers, thin-layer chromatography with silver nitrate and gas-liquid chromatography with radioactivity monitoring. Bile salt micelles of alternately labeled monoacylglycerols and free fatty acids were incubated with everted sacs of intestinal mucosa for various periods of time and the diacylglycerols were isolated by solvent extraction and thin-layer chromatography. Stereospecific analyses of the X-1,2-diacylglycerols labeled from 2-monoacylgiycerols showed that the sn-1,2-isomers (45–55%) were slightly in excess of the sn-2,3-isomers (34–45%) with the X-1,3-diacylglycerols accounting for the rest of the radioactivity (5–10%). This suggests that racemic diacylglycerols may be intermediates in the resynthesis of dietary fat in rat intestinal mucosa. Detailed analyses of the molecular species of the sn-1,2-diacylglycerols labeled from free fatty acids revealed that 10–45% of the total did not contain the acid present in the 2-monoacylglycerol supplied, and therefore had originated from the phosphatidic acid pathway. These findings are at variance with those obtained in isolated microsomes, which have suggested an inhibition of the phosphatidic acid pathway by monoacylglycerols as well as have given evidence of an exclusive synthesis of sn-1,2-diacylglycerols from 2-monoacylglycerols.


1970 ◽  
Vol 48 (9) ◽  
pp. 631-639 ◽  
Author(s):  
M. Yurkowski ◽  
B. L. Walker

Mucosal lipids were isolated from the proximal, middle, and distal intestinal sections of rats fed diets containing either 10% corn oil or 10% hydrogenated coconut oil, the latter diet being deficient in essential fatty acids. By a combination of column and thin-layer chromatography, the lipids were fractionated and the major components found to consist of triglycerides, free fatty acids, cholesterol, phosphatidylcholine, and phosphatidylethanolamine. Several minor constituents were present. Triglycerides and free fatty acids were generally present in higher concentrations in animals fed corn oil, and the concentration of mucosal triglycerides decreased towards the distal end of the intestine whereas free fatty acids increased in this group. Essential fatty acid deficiency resulted in lower levels of linoleic and arachidonic acids and higher levels of palmitoleic, oleic, and eicosatrienoic acids in the mucosal lipids. Mono- and di-enoic fatty acids tended to decrease in concentration from the proximal to the distal end of the intestine; the polyunsaturated acids and, to some extent, the saturated acids, were lowest in the proximal section of the intestine.


1993 ◽  
Vol 264 (5) ◽  
pp. R957-R962 ◽  
Author(s):  
V. Lemaire ◽  
M. Le Moal ◽  
P. Mormede

We have shown previously that chronic social stress has differential effects on adrenal weight and on tyrosine hydroxylase (TH) and phenylethanolamine N-methyltransferase (PNMT) specific activity, depending on the experimental design. To determine the role of the sympathetic nervous system and of the hypothalamo-pituitary-adrenocortical axis (HPAA) in these modifications, we studied the mechanisms of regulation of these parameters in basal conditions as well as in response to reserpine treatment and chronic social stress in the Wistar strain of rats. We found that the adrenal weight is mostly dependent on the activity of the HPAA, which is increased in male rats living in mixed-sex colonies. PNMT specific activity is regulated by splanchnic innervation, confirming that its induction by social instability is a consequence of sympathetic nervous system hyperactivity. The increase of TH specific activity, as seen in unstable, mixed-sex colonies, is not under sympathetic control. However, we show that the pituitary may exert a tonic inhibitory influence, dependent on the sympathetic innervation. These data confirm that the HPAA and the sympathetic nervous system may be independently triggered in chronic social stress conditions.


2010 ◽  
Vol 299 (3) ◽  
pp. R813-R822 ◽  
Author(s):  
Susan J. Melhorn ◽  
Eric G. Krause ◽  
Karen A. Scott ◽  
Marie R. Mooney ◽  
Jeffrey D. Johnson ◽  
...  

In the present study, we examined meal patterns during and after exposure to the visible burrow system (VBS), a rodent model of chronic social stress, to determine how the microstructure of food intake relates to the metabolic consequences of social subordination. Male Long-Evans rats were housed in mixed-sex VBS colonies (4 male, 2 female) for 2 wk, during which time a dominance hierarchy formed [1 dominant male (DOM) and 3 subordinate males (SUB)], and then male rats were individually housed for a 3-wk recovery period. Controls were individually housed with females during the 2-wk VBS period and had no changes in ingestive behavior compared with a habituation period. During the hierarchy-formation phase of VBS housing, DOM and SUB had a reduced meal frequency, whereas SUB also had a reduced meal size. However, during the hierarchy-maintenance phase of VBS housing, DOM meal patterns did not differ from controls, whereas SUB continued to display a reduced food intake via less frequent meals. During recovery, DOM had comparable meal patterns to controls, whereas SUB had an increased meal size. Hypothalamic neuropeptide Y (NPY) mRNA levels were not different between these groups during the experimental period. Together, the results suggest that exposure to chronic social stress alters ingestive behavior both acutely and in the long term, which may influence the metabolic changes that accompany bouts of stress and recovery; however, these differences in meal patterns do not appear to be mediated by hypothalamic NPY.


1999 ◽  
Vol 77 (10) ◽  
pp. 755-762 ◽  
Author(s):  
Xiaochen Si ◽  
R Clinton Webb ◽  
Joyce M Richey

A high fructose diet induces hypertension, hyperinsulinemia - insulin resistance, and hypertriglyceridemia (syndrome X). In this study, we investigated the role of an abnormal lipid profile in mediating fructose-induced hypertension. We hypothesized that bezafibrate, a lipid-lowering drug, would reduce elevated blood pressure and inhibit increased vascular reactivity in fructose-fed rats. Male rats were placed on four different diets: group 1 was fed standard chow (n = 6); group 2 was fed 60% fructose (n = 5); group 3 was fed fructose plus bezafibrate (30 mg·kg-1·day-1; drinking water; n = 5); and group 4 was fed standard chow plus bezafibrate (n = 6). In addition, the direct effects of very low density lipoprotein (VLDL) on vascular reactivity were examined. Bezafibrate treatment lowered blood pressure, free fatty acids, and triglycerides in the fructose-fed group, suggesting that lipid abnormalities play a role in the elevation of blood pressure in the fructose-induced hypertensive rat. Aortae from fructose-fed rats were hyperresponsive to the calcium channel agonist Bay K 8644, which was normalized with bezafibrate treatment. Incubation of aortae in a VLDL medium resulted in increased responsiveness to Bay K 8644, lending further support to lipid abnormalities altering vascular reactivity. An altered lipid profile evidenced by elevated triglycerides and free fatty acids is causally related to the development of high blood pressure and increased vascular reactivity in the fructose-induced hypertensive rat.Key words: Sprague-Dawley rats, hypertriglyceridemia, free fatty acids, vascular reactivity, aortae.


1994 ◽  
Vol 72 (2) ◽  
pp. 113-116 ◽  
Author(s):  
Jacques LeBlanc ◽  
Julie Soucy

The effect of various doses of i.p. injection of the adenosine receptor agonist (R)-phenylisopropyladenosine (R-PIA), ranging from nanomolar to micromolar concentrations, on plasma levels of free fatty acids, glucose, insulin, glucagon, ACTH, and corticosterone was examined in 200-g male rats. At the lowest dose of R-PIA (0.005 μmol/kg), a marked decrease in plasma insulin and free fatty acids was observed. This effect on free fatty acids persisted up to the highest concentration of R-PIA (50 μmol/kg). The insulin response showed a similar pattern except at the highest concentration, when the plasma levels were within normal ranges. A 100% increase in plasma glucose was found, but only with doses of 0.5 μmol/kg and above, suggesting an A2 receptor influence, possibly related to the elevation of plasma glucagon observed with the same doses of R-PIA. It has been shown that caffeine, an antagonist of adenosine, stimulates the pituitary–adrenal axis. Surprisingly, it was shown that R-PIA produces the same effect, as evidenced by the marked elevation of both plasma ACTH and corticosterone at concentrations of 0.5 μmol/kg and higher. It is suggested that this centrally mediated effect is due to a primary peripheral action.Key words: adenosine, glucose, free fatty acids, insulin, glucagon, ACTH, corticosterone.


Sign in / Sign up

Export Citation Format

Share Document