scholarly journals Increased loss and decreased synthesis of hepatic glutathione after acute ethanol administration. Turnover studies

1985 ◽  
Vol 225 (3) ◽  
pp. 565-572 ◽  
Author(s):  
H Speisky ◽  
A MacDonald ◽  
G Giles ◽  
H Orrego ◽  
Y Israel

The effect of acute ethanol administration on rates of synthesis and utilization of hepatic glutathione (GSH) was studied in rats after a pulse of [35S]cysteine. A 35% decrease in hepatic GSH content 5h after administration of 4 g of ethanol/kg body wt. was accompanied by a 33% increase in the rate of GSH utilization. The decrease occurred without increases in hepatic oxidized glutathione (GSSG) or in the GSH/GSSG ratio. The rate of non-enzymic condensation of GSH with acetaldehyde could account for only 6% of the rate of hepatic GSH disappearance. The increased loss of [35S]GSH induced by ethanol was not accompanied by an increased turnover; rather, a 30% inhibition of GSH synthesis balanced the increased rate of loss, leaving the turnover rate unchanged. The rate of acetaldehyde condensation with cysteine in vitro occurred at about one-third of the rate of GSH loss in ethanol-treated animals. However, ethanol induced only a minor decrease in liver cysteine content, which did not precede, but followed, the decrease in GSH. The characteristics of 2-methylthiazolidine-4-carboxylic acid, the condensation product between acetaldehyde and cysteine, were studied and methodologies were developed to determine its presence in tissues. It was not found in the liver of ethanol-treated animals. Ethanol administration led to a marked increase (47%) in plasma GSH in the post-hepatic inferior vena cava, but not in its pre-hepatic segment. Data suggest that an increased loss of GSH from the liver constitutes an important mechanism for the decrease in GSH induced by ethanol. In addition, an inhibition of GSH synthesis is observed.

2017 ◽  
Vol 313 (3) ◽  
pp. H676-H686 ◽  
Author(s):  
Bridget M. Seitz ◽  
Hakan S. Orer ◽  
Teresa Krieger-Burke ◽  
Emma S. Darios ◽  
Janice M. Thompson ◽  
...  

Serotonin [5-hydroxytryptamine (5-HT)] causes relaxation of the isolated superior mesenteric vein, a splanchnic blood vessel, through activation of the 5-HT7 receptor. As part of studies designed to identify the mechanism(s) through which chronic (≥24 h) infusion of 5-HT lowers blood pressure, we tested the hypothesis that 5-HT causes in vitro and in vivo splanchnic venodilation that is 5-HT7 receptor dependent. In tissue baths for measurement of isometric contraction, the portal vein and abdominal inferior vena cava relaxed to 5-HT and the 5-HT1/7 receptor agonist 5-carboxamidotryptamine; relaxation was abolished by the 5-HT7 receptor antagonist SB-269970. Western blot analyses showed that the abdominal inferior vena cava and portal vein express 5-HT7 receptor protein. In contrast, the thoracic vena cava, outside the splanchnic circulation, did not relax to serotonergic agonists and exhibited minimal expression of the 5-HT7 receptor. Male Sprague-Dawley rats with chronically implanted radiotelemetry transmitters underwent repeated ultrasound imaging of abdominal vessels. After baseline imaging, minipumps containing vehicle (saline) or 5-HT (25 μg·kg−1·min−1) were implanted. Twenty-four hours later, venous diameters were increased in rats with 5-HT-infusion (percent increase from baseline: superior mesenteric vein, 17.5 ± 1.9; portal vein, 17.7 ± 1.8; and abdominal inferior vena cava, 46.9 ± 8.0) while arterial pressure was decreased (~13 mmHg). Measures returned to baseline after infusion termination. In a separate group of animals, treatment with SB-269970 (3 mg/kg iv) prevented the splanchnic venodilation and fall in blood pressure during 24 h of 5-HT infusion. Thus, 5-HT causes 5-HT7 receptor-dependent splanchnic venous dilation associated with a fall in blood pressure. NEW & NOTEWORTHY This research is noteworthy because it combines and links, through the 5-HT7 receptor, an in vitro observation (venorelaxation) with in vivo events (venodilation and fall in blood pressure). This supports the idea that splanchnic venodilation plays a role in blood pressure regulation.


1963 ◽  
Vol 28 (1) ◽  
pp. 73-78 ◽  
Author(s):  
J. R. DANIELS ◽  
S. M. KALMAN

SUMMARY Adult Long Evans rats were ovariectomized and, one month later, were subjected to partial hepatectomy. Immature Long Evans rats were either partially hepatectomized in one step, or complete hepatectomy was accomplished by a two-stage operation which included ligation of the inferior vena cava followed by a partial evisceration. The response of these animals to injected oestradiol was compared with that of sham-operated controls by observing uptake of water by the uterus in vivo, and also by estimating the ability of surviving uterine fragments to accumulate radioactive α-amino-isobutyric acid in vitro. It was found that partial or complete hepatectomy did not abolish the response of the uterus to oestradiol. These results seem to exclude an essential role for the liver in the early response of a target organ to an oestrogenic hormone.


2019 ◽  
Vol 4 (01) ◽  
pp. 27-30
Author(s):  
Sandeep T. Laroia ◽  
Justin J. Guan ◽  
Archana T. Laroia ◽  
Lucas Lenhart ◽  
Antony J. Hayes

Abstract Introduction Inferior vena cava (IVC) filter tilt is a common complication that occurs during and after filter placement. Severe tilting leads to reduced filter efficacy, lower retrieval success, and higher complication rates during retrieval. We present a novel catheter technique to correct severely tilted cone-shaped IVC filters without having to retrieve and replace the existing filter. Methods A retrospective review was performed for patients at our institution over three years who had severely tilted filters and underwent correction with the catheter technique. Indications for filter placement were categorized, and patient age, gender, tilt correction outcome, and complication rates were collected and analyzed. After severe tilting was noted on post-IVC filter deployment venogram, a Sos catheter was passed via the same femoral access site used for the filter placement. The catheter tip was reformed inside the cone of the filter and was used to push the filter tip back toward midline. Completion venogram was taken to document the amelioration of the tilt. Results Out of 28 patients who were found to have severely tilted filters on deployment and underwent correction with the catheter technique, 27/28 (96.4%) had successful correction. One (3.6%) had a minor complication where the filter struts became entangled with the catheter tip; however, simple maneuvering of the catheter and use of a stiff wire to straighten the catheter loop freed up the entanglement. No major complications occurred. Conclusion This technique is safe, effective, obviates filter replacement, and can be considered an additional management option for severe IVC filter tilt during placement.


1981 ◽  
Vol 241 (2) ◽  
pp. G176-G181
Author(s):  
R. S. Green ◽  
R. G. MacDermid ◽  
R. L. Scheig ◽  
J. J. Hajjar

The acute effect of ethanol on amino acid absorption across the in vivo rat intestine was studied using single-pass continuous perfusion and recirculation techniques. The single-pass steady-state perfusion was used to examine the effect on the entire small intestine and recirculation perfusion to examine the effect on short intestinal segments and to limit ethanol absorption. Unlike the in vitro findings of other investigators, ethanol does not cause inhibition of net amino acid absorption in vivo unless the alcohol is perfused in 2 M or higher concentrations. The inhibition that is observed at these concentrations is very likely due to severe injury and shedding of intestinal cells as evidenced by an increased recovery of DNA in the perfusates. The findings suggest that acute ethanol administration, in concentrations that are comparable to those found in the upper intestines of humans after the ingestion of moderate doses of alcohol, does not have a prominent effect on amino acid absorption across the in situ rat intestine. Under these conditions, the ethanol inhibition of active absorption is masked by enhanced diffusion of the amino acids across the intestine.


1981 ◽  
Author(s):  
Ph Schneider ◽  
M Ruegg ◽  
F Bachmann

Highly purified lew molecular weight urokinase (LMR-UK), moving on SDS-PAGE (reduced and nan-reduced) as a single band of 32 kdalton, was labelled with 125I by the chlora- mine-T method. 106 cpn of this 125I-LMr-UK (94% TCA preci- pitable) were injected into the inferior vena cava of la- par atomized albino rats, which were maintained at 37°C. Blood samples were collected by cardiac puncture 5, 30 and 90 min respectively after the injection. Serun, obtained from these samples, was fractionated on a Sephadex G-100 column, calibrated with proteins of known Mr. Radioactivity was measured in the collected fractions.In the 5 min sample, the radioactivity was distributed in 2 peaks, corresponding to 32 kdalton and to < 70 kdalton respectively. In the 30 min sample, the distribution was characterized by a diminution of the 32 kdalton peak and the appearance of a third peak corresponding to a Mr of < 4 kdalton. In the 90 min sample, the LMr-UK peak had disappeared almost completely. About 40% of the 125I-activity was present in a skewed high Mr peak with a broad maximum in the 85-100 kdalton region; ≥ 60% of the 125I-activity was recovered in late fractions corresponding to < 4 kdalton. In control experiments, pooled rat serum was incubated in vitro with 125I-LMr-UK for 5, 30 and 90 min respectively and samples were fractionated on the same column. The radioactivity distribution shewed only the 32 and > 70 kdalton peaks, but no < 4 kdalton peak.These results suggest that LMr-UK is complexed to a carrier protein, both in vivo and in vitro, but that it is degraded into small fragments in vivo only. Attempts to characterize the nature of these complexes are in progress.


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