Hypoxia differentially regulates nutrient transport in rat jejunum regardless of luminal nutrient present

2002 ◽  
Vol 283 (6) ◽  
pp. G1336-G1342 ◽  
Author(s):  
K. A. Kles ◽  
K. A. Tappenden

Aggressive enteral nutrition and poor intestinal perfusion are hypothesized to play an important pathogenic role in nonocclusive small bowel necrosis. This study tests the hypothesis that glucose and glutamine transport are differentially regulated during hypoxia regardless of the luminal nutrient present. Sprague-Dawley rats (247 ± 3 g; n = 16) were randomized to receive 1 h of intestinal hypoxia or serve as normoxic controls. During this hour, jejunal loops were randomized to receive in situ perfusions of mannitol, glucose, or glutamine. When compared with normoxic groups, glucose but not glutamine transport was impaired ( P < 0.001) during hypoxia. Messenger RNA abundance of the sodium glucose cotransporter sodium-dependent glucose cotransporter-1 (SGLT-1) and neutral basic amino acid transporter Bo did not differ with hypoxia or nutrient perfused. Jejunal brush-border SGLT-1 abundance was decreased ( P= 0.039) with hypoxia; however, total cellular SGLT-1 protein abundance did not differ among treatment groups. These data indicate that SGLT-1 activity is regulated during hypoxia at the posttranslational level. Additional information regarding the mechanisms regulating nutrient transport in the hypoperfused intestine is critical for optimizing the composition of enteral nutrient formulas.

1994 ◽  
Vol 71 (1) ◽  
pp. 13-27 ◽  
Author(s):  
A. P. Pine ◽  
N. S. Jessop ◽  
J. D. Oldham

To determine the contribution of tissue protein reserves to lactational performance, multiparous female Sprague-Dawley rats were mated, caged individually and offered a diet high in protein (215 g crude protein (N × 6·25; CP)/kg dry matter (DM);H) ad lib. until day 12 of gestation. Subsequently half the rats continued to receive diet H while the remainder were offered a diet low in protein (65 g CP/kg DM;L) until parturition. This treatment aimed to produce a difference in carcass protein at parturition. On day 1 of lactation females were allocated to either diet H or a low-protein diet (90 g CP/kg DM; L2) offered until day 13 of lactation, giving four lactation treatment groups HH, HL2, LH and LL2. Groups of females were slaughtered on days 2 and 12 of gestation and days 1 and 13 of lactation and carcass and major organs were analysed. Weight gain of standardized litters was used as an indicator of lactational performance. Maternal carcass protein contents at parturition were 43·5 (SE 1·2) and 38·7 (SE 0·8) g (P < 0·01) for diets H and L respectively. During lactation there was little change in carcass protein content of HH rats while LH rats appeared to replenish their depleted reserves. Food intake or lactational performance did not differ between these two groups. HL2 and LL2 rats lost carcass protein with HL2 rats losing more than LL2 rats (P < 0·05). Intake and lactational performance were reduced compared with that on diet H (P < 0.05) but for the first 6 d of lactation were both greater (P < 0·05) for diet HL2 than for diet LL2. All four groups showed a considerable loss of body fat during lactation which was not affected by diet. The ability of HL2 rats to catabolize more protein and consume more food allowed them to sustain a greater lactationai performance. Previous maternal protein depletion had no influence on lactationai performance as long as an adequate supply of dietary protein was provided.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Na Cui ◽  
Hao Wang ◽  
Yun Long ◽  
Longxiang Su ◽  
Dawei Liu

The aim of this study is to determine the mechanism of sepsis-induced vascular hyperpermeability and the beneficial effect of glucocorticoid in protecting vascular endothelium. Male Sprague-Dawley rats were given either a bolus intraperitoneal injection of a nonlethal dose of LPS (Escherichia coli055:B5, 10 mg/kg, Sigma) or vehicle (pyrogen-free water). Animals of treatment groups were also given either dexamethasone (4 mg/kg, 30 min prior to LPS injection) or the matrix metalloproteinases (MMPs) inhibitor doxycycline (4 mg/kg, 30 min after LPS injection). Both activities and protein levels of MMP-2p<0.001and MMP-9p<0.001were significantly upregulated in aortic homogenates from LPS-treated rats, associated with decreased ZO-1p<0.001and syndecan-1p=0.011protein contents. Both dexamethasone and doxycycline could significantly inhibit MMPs activity and reserve the expressions of ZO-1 and syndecan-1. The inhibition of MMPs by dexamethasone was significantly lower than that by doxycycline, while the rescue of syndecan-1 expression from LPS-induced endotoxemic rat thoracic aorta was significantly higher in the dexamethasone-treated compared to the doxycycline-treatedp=0.03. In conclusion, activation of MMPs plays important role in regulating ZO-1 and syndecan-1 protein levels in LPS mediated endothelial perturbation. Both dexamethasone and doxycycline inhibit activation of MMPs that may contribute to the rescue of ZO-1 and syndecan-1 expression.


2018 ◽  
Vol 52 (6) ◽  
Author(s):  
Maria Concepcion C. Sison ◽  
Lynn Crisanta R. Panganiban ◽  
Daisy Mae A. Bagaoisan ◽  
Nelia P. Cortes-Maramba

Objective. To To evaluate potential effects of the aqueous extract of Quassia amara L. leaves on the cardiovascular and respiratory systems of adult male Sprague- Dawley rats. Methods. The cardiovascular and respiratory effects of the Quassia amara L. leaf extract on adult male SpragueDawley rats were assessed using non-invasive blood pressure (NIBP) determination and head-out plethysmography, respectively, in a randomized, parallel group study. Mean observations of blood pressure and heart rate were recorded at different time periods after dosing. Respiratory flow and irritation effects were evaluated using mean observations of respiratory rate (RR), tidal volume (TV), mid-expiratory flow rate (EF50), time of inspiration (TI) and expiration (TE), and time of break (TB) and pause (TP). Results. There were no significant differences among the control and the treatment groups in SBP, DBP and HR parameters. The extract showed statistically significant effect on mean RR by time period (F=2.45, p=0.0234), trends over time of TV among the dose groups (F=2.00, p=0.0202), and EF50 among dose groups ((F=3.11, p=0.0422). However, these did not correlate with the changes in the time of break (TB) and time of pause (TP) which are more sensitive and specific tests for respiratory irritation. Conclusion. Aqueous leaf extract of Quassia appeared to have no significant effects on SBP, DPB, Pulse pressure, and HR. There are no conclusive dose-related respiratory flow or pulmonary irritation effects.


2005 ◽  
Vol 13 (18) ◽  
pp. 2227
Author(s):  
Zhu-Lin Yang ◽  
Xing-Hui Deng ◽  
Le-Ping Yang ◽  
Qing-Long Li ◽  
Wen-Tao Fan ◽  
...  

1985 ◽  
Vol 248 (1) ◽  
pp. E70-E74 ◽  
Author(s):  
R. A. Bennett ◽  
P. C. Colony ◽  
J. L. Addison ◽  
D. E. Rannels

The effects of adrenalectomy, with and without subsequent glucocorticoid replacement therapy, on postpneumonectomy compensatory lung growth in the rat were investigated. Male Sprague-Dawley rats (200-230 g) were subjected to no operation (UNOP), left pneumonectomy (PNX), or PNX preceded by bilateral adrenalectomy 5 days earlier (ADX/PNX). At 14 days post-PNX, when compensatory lung growth is normally complete in 200-g rats, right lung (RL) dry weights of PNX (263 +/- 6 mg, n = 26) and ADX/PNX (334 +/- 13 mg, n = 25) rats were increased 58 and 101%, respectively, relative to UNOP controls (166 +/- 5 mg, n = 10). Increases in total DNA, RNA, and protein in the right lungs of PNX and ADX/PNX rats occurred in proportion to RL dry mass. The increase in all parameters examined in PNX and ADX/PNX rats at 7 days post-PNX was half that at 14 days, indicating linear lung growth in both treatment groups. The stimulatory effect of ADX on lung growth was blocked by hydrocortisone acetate (HCA), administered intraperitoneally in daily doses of 5 mg/kg, beginning on the day of PNX. The RL dry weights of HCA-treated ADX/PNX rats (241 +/- 7 mg, n = 10) did not differ significantly from the corresponding value in PNX rats (270 +/- 14 mg, n = 7). The lower RL weights in the HCA-treated rats resulted from an inhibition of cell division, as evidenced by the total RL DNA content, which was similar to that in PNX animals.(ABSTRACT TRUNCATED AT 250 WORDS)


Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 950 ◽  
Author(s):  
Katrina Frost ◽  
Maaria Shah ◽  
Vivian S.Y. Leung ◽  
Daniel S.J. Pang

Carbon dioxide and isoflurane are widely used for killing rats, yet may not truly achieve “euthanasia”, because they elicit aversion. The inhalant anesthetic desflurane is faster acting than isoflurane, representing a potential refinement. Using an aversion-avoidance paradigm, 24 rats were exposed to isoflurane or desflurane (n = 12 per group) at initial exposure. Fourteen rats were then re-exposed to isoflurane or desflurane (n = 7 per group), after a 7 days washout period. Initial exposure: time to recumbency was faster for desflurane than isoflurane (p = 0.0008, 95% CI [-12.9 to 32.6 s]), with 9/12 and 6/12 rats becoming recumbent, respectively. At initial exposure, there was no difference between groups in time to withdrawal (p = 0.714). At re-exposure, all rats withdrew and no rats became recumbent. Time to withdrawal at re-exposure did not differ between treatment groups (p = 0.083). Compared to initial exposure, time to withdrawal during re-exposure was similar for isoflurane (p = 0.228) and faster with desflurane (p = 0.012, 95% CI [19.1 to 49.5 s]). Isoflurane and desflurane are similarly aversive, with aversion increasing at re-exposure. The shorter time from exposure to recumbency with desflurane indicates that any distress is of a shorter duration when compared with isoflurane.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Latifah Saiful Yazan ◽  
Muhamad Firdaus Shyfiq Muhamad Zali ◽  
Razana Mohd Ali ◽  
Nurul Amira Zainal ◽  
Nurulaidah Esa ◽  
...  

Ethnopharmacological Relevance. Colon cancer has been a major problem worldwide. Kelulut honey (KH) is produced by the stingless bees fromTrigonaspecies and has strong antioxidant activities that could be one of the potential chemopreventive agents from natural resources.Aim of This Study. This study investigated the chemopreventive properties and toxicity of KH in Sprague Dawley rats induced with azoxymethane (AOM).Material and Method. Twenty-four male Sprague Dawley rats aged 5 weeks were divided into 4 groups: (G1) untreated group not induced with AOM, (G2) untreated group induced with AOM, (G3) treated group induced with AOM, and (G4) treated group not induced with AOM. Injection of AOM (15 mg/kg) was via intraperitoneal route once a week for two subsequent weeks. The treatment groups were given oral administration of KH (1183 mg/kg body weight) twice daily for 8 weeks.Results. Treatment with KH significantly reduced the total number of aberrant crypt foci (ACF) and aberrant crypts (AC) and crypt multiplicity. KH was not toxic to the animals since the level of blood profile parameters, liver enzymes, and kidney functions was in normal range.Conclusions. The current finding shows that KH has chemopreventive properties in rats induced with colorectal cancer and also was found not toxic towards the animals.


2014 ◽  
Vol 34 (1) ◽  
pp. 65-73 ◽  
Author(s):  
C Zhou ◽  
Y Zhang ◽  
S Yin ◽  
Z Jia ◽  
A Shan

The aim of the present research was to examine the toxic influence of different doses of zearalenone (ZEN) on the liver, especially oxidative stress induced by ZEN on the liver. A total of 48 pregnant Sprague-Dawley rats were randomly assigned into 4 treatments groups with 12 animals in each. The rats were fed with a normal diet treated with 0 mg/kg (control), 50 mg/kg (treatment 1), 100 mg/kg (treatment 2), or 150 mg/kg (treatment 3) ZEN in feed on gestation days (GDs) 0–7 and then all the rats were fed with a normal diet on GDs 8–20. The experimental period lasted 21 days. The results showed that exposure to ZEN induced increase in aspartate amino transferase, alanine aminotransferase, and alkaline phosphatase activities and decrease in total protein and albumin content in a dose-dependent manner and also induce decrease in superoxide dismutase and glutathione peroxidase activities and increase in malondialdehyde content in a dose-dependent manner in the serum and the liver. The increased transcription of cytochrome P450 2E1 (CYP2E1) was detected in the liver after exposure to ZEN. These results suggested that ZEN not only caused damage in the liver of pregnant rats in a dose-dependent manner but also induced the messenger RNA expression of CYP2E1 in the liver.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Natalie M. Wilson ◽  
Matthew S. Ripsch ◽  
Fletcher A. White

Aim. Nonsteroidal anti-inflammatory drugs or opioids are commonly used to control surgical pain following veterinary and clinical procedures. This study evaluated the efficacy of postoperative ketorolac or buprenorphine following abdominal surgery. Main Methods. Mean arterial pressure (MAP), heart rate, animal activity, corticosterone levels, and a nociceptive sensitivity assay were used to evaluate 18 adult male Sprague-Dawley rats which underwent aortic artery occlusion for implantation of a radiotelemetry device. The animals were treated postoperatively with intraperitoneal injections of vehicle, ketorolac (10 mg/kg), or buprenorphine (0.06 mg/kg) every 8 hours for 3 days. Key Findings. There were no consistent significant changes in any of the telemetry parameters after treatment with ketorolac compared with no saline treatment with the exception of increased MAP in the buprenorphine group during the first 48 hours when compared with other treatment groups. There was a sustained increase in fecal corticosterone levels from baseline on days 2–7 with buprenorphine compared with vehicle- or ketorolac-treated animals. All treatment conditions displayed reduced paw withdrawal thresholds (PWTs) from day 1 to day 21 following surgery. Compared with the vehicle treatment group, buprenorphine-treated animals exhibited significantly lower PWT levels from day 4 to 14 days. Significance. Given the prolonged increase in fecal corticosterone levels and pronounced changes in tactile hyperalgesia behavior in rodents subjected to buprenorphine treatment, these data suggest that ketorolac may be superior to buprenorphine for the treatment of postprocedure pain behavior in rodents.


Gut ◽  
1998 ◽  
Vol 43 (1) ◽  
pp. 22-28 ◽  
Author(s):  
M R Uhing

Background—The significance of Na-nutrient cotransport induced alterations in paracellular permeability is controversial. Most previous studies have measured intestinal permeability using in vitro methods or in vivo methods immediately after surgical bowel manipulation, and therefore may not be applicable to normal physiological conditions.Aims—To determine whether activation of Na coupled nutrient transport increases intestinal permeability under normal physiological conditions.Methods—The effect of Na-nutrient cotransport on intestinal permeability was measured in unrestrained, unanaesthetised, chronically catheterised male Sprague-Dawley rats using two different methods: measurement of the rate of absorption of passively absorbed hexoses, mannitol and l-glucose; and measurement of the mannitol:urea diffusion ratio.Results—l-Glucose and mannitol absorption were not increased in the presence ofd-glucose, alanine, maltose, or peptides. The mannitol:urea diffusion ratio was not increased by the presence ofd-glucose. The presence of d-glucose in the intestinal lumen for 20 minutes did not alter intestinal permeability.Conclusions—Under normal physiological conditions, Na coupled nutrient transport does not increase intestinal permeability.


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