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1.
The goals of the present study were to determine whether the infusion of a glucose solution into the portal vein is tolerated in cows and whether the glucose concentration differs after administration of glucose into the jugular vein and portal vein. Fifteen healthy Swiss Braunvieh cows were used. An indwelling catheter was placed in both jugular veins and a balloon-tipped indwelling catheter with a diameter of 2 mm was placed in the portal vein under the guidance of ultrasonography. Three cows received 500 ml of 20% glucose solution over 60 min via the left jugular vein. Three other cows received the same solution over 60 min via the portal vein. Blood samples were collected from the right jugular vein before and for 24 h after the infusion of glucose for the determination of the concentrations of glucose and bilirubin and the activities of glutamate dehydrogenase, sorbitol dehydrogenase and gamma-glutamyl transferase. Infusion via the portal vein did not result in abnormalities in the general condition of the cows or increases in the concentration of bilirubin or the activities of liver enzymes. The blood glucose concentration increased to the same extent after both intraportal and intrajugular infusion. Over a 12-h period, three cows received 10 l of 20% glucose solution via the left jugular vein and three others received the same solution over a 12-h period via the portal vein. Blood samples were collected from the right jugular vein before and for 30 h after the start of infusion. Infusion via the portal vein did not affect the general condition of the cows or the activities of the liver enzymes. There was no significant difference in the blood glucose concentration between the two groups throughout the study.  相似文献   

2.
To study bile acid metabolism in the pig, indwelling catheters were surgically placed in the hepatic portal vein and the anterior vena cava of 12-17 kg crossbred pigs. The pigs were fed ad libitum for one hr at 0800 and 1600 hrs daily. Two weeks after the surgery, 50 microCi of 24[14C] chenodeoxycholic acid were infused into the hepatic portal vein. The radioactivity in plasma from the two veins was monitored hourly for six hrs following each of six consecutive meals over a 3-day period. Fecal and urine radioactivity were determined for 14 days. It was found that the peak levels of radioactivity in the plasma of both veins were reached within two hrs post-feeding. The biological half-life of chenodeoxycholic acid was determined to be 6.4 days.  相似文献   

3.
In six experiments 43 castrated male conventional pigs weighing 25-41 kg were catheterised by inserting a cannula via the jugular vein into the cranal caval vein. The catheters were taped to the spinal neck region where the tap stops were located. Antimicrobial agents were not applied. One pig died 32 hour after surgery from Porcine Stress Syndrome. The catheters remained patent for at least nine days in 38 of the remaining 42 animals (90%). In two animals the catheter by mistake was not inserted into the jugular vein. Two animals got catheters with a one-way blockage four days after surgery. In these animals autopsy revealed thrombosis and phlebitis of the occluded vein and a valve-like thrombus at the tip of the catheters. In seven of the 43 pigs the effects of anaesthesia, surgery and catherisation were followed using rectal temperature and haematological and some blood biochemical parameters for nine days after the surgery. It is concluded that this catheterisation technique, without application of antimicrobial agents, can be used well for experimental infections and pharmacokinetic studies.  相似文献   

4.
To determine the absorption and metabolism of 17β-estradiol (E2) by the rectum of the pig, 10 mg of crystalline E2 was placed in the rectum of prepubertal gilts in Experiment 1. Blood samples were subsequently obtained from hepatic portal and jugular veins and plasma was assayed for E2, estrone (E1), 17β-estradiol-glucuronide (E2G), estrone-glucuronide (E1G) and estrone-sulfate (E1S). Concentration of E2, E1, E2G, E1G, and E1S rose in the hepatic portal vein within 30 min and remained elevated for several hr. Concentrations of E2 in the hepatic portal vein represented 3% of the total estrogen detected in the hepatic portal vein during the 5 hr sampling period, indicating that most of the E2 was metabolized prior to entering the hepatic portal vein after absorption by the rectal mucosa. Concentrations of E2, E1, E2G, E1G, and E1S rose in the jugular vein and remained elevated for several hr. The rise in E2 and E1 in the jugular vein may have come from E2 and E1 in venous circulation from the rectum that entered the inferior vena cava bypassing the hepatic portal vein and liver. The net result of absorption of E2 from the rectum of gilts was a large rise in unconjugated and conjugated E2 and E1 in the peripheral circulation. In Experiment 2 prepubertal gilts fitted with jugular, hepatic portal, duodenal, and gall bladder catheters were infused into the duodenum with bile from pregnant gilts. Concentrations of E2, E1, E2G, and E1G were determined in gallbladder bile of gilts before infusion and at 470 min. Concentrations of E2G and E1G were determined in hepatic portal and jugular plasma before and after infusion of bile. A cholagogue was given at 480 min and E2G and E1G were measured in plasma from 490 min to 960 min. Concentrations of E2 and E1 in gallbladder bile rose at 470 min and fell to basal concentrations at 970 min. In gilts given the cholagogue, E2G and E1G in both the jugular and hepatic portal veins rose significantly over those in gilts not given the cholagogue. Bile estrogens circulate via the enterohepatic route and factors that influence secretion of estrogens in bile can influence concentrations of circulating estrogens.  相似文献   

5.
OBJECTIVE: To document blood nitric oxide concentrations in the portal vein and systemic circulation in a rat model of acute portal hypertension and compare values with a control group and a sham surgical group. ANIMALS: 30 rats; 10 controls (group 1), 10 sham surgical (group 2), and 10 rats with surgically induced acute portal hypertension (group 3). PROCEDURE: Following induction of anesthesia, catheters were placed surgically in the carotid artery, jugular, and portal veins of group 2 and 3 rats and in the carotid artery and jugular vein of group 1 rats. Baseline heart and respiratory rates, rectal temperature, and vascular pressure measurements were obtained, and blood was drawn from all catheters for baseline nitric oxide (NO) concentrations. Acute portal hypertension was induced in the group 3 rats by tying a partially occluding suture around the portal vein and a 22-gauge catheter. The catheter was then removed, resulting in a repeatable degree of portal vein impingement. After catheter placement, all variables were remeasured at 15-minute intervals for 3 hours. RESULTS: Blood nitric oxide concentrations were greater in all vessels tested in group 3 than in group 2 rats. CONCLUSIONS AND CLINICAL RELEVANCE: Acute portal hypertension in this experimental model results in increased concentrations of NO in the systemic and portal circulation. On the basis of information in the rat, it is possible that increased NO concentrations may develop in dogs following surgical treatment of congenital portosystemic shunts if acute life-threatening portal hypertension develops. Increased NO concentrations may contribute to the shock syndrome that develops in these dogs.  相似文献   

6.
Estrogen, progesterone or testosterone were administered orally to ovariectomized gilts fitted with indwelling catheters. Blood samples were taken from the jugular and hepatic portal veins at intervals varying from a few minutes to daily over periods that varied from 1 d to several months. Concentrations of free steroids rose dramatically in the hepatic portal vein within a few min of feeding steroids and remained high for 3-8 hr before declining to base levels. Concentrations in the jugular vein sometimes rose very slightly for the same period. At 48 hr after administration the concentrations remained at baseline in the hepatic portal vein, but rose several-fold in the jugular and remained elevated for several days. Autotransplantation of the ovaries to the intestine resulted in very large ovaries consisting of many large, heavily luteinized cystic follicles. Concentrations of progesterone and estrogen in the hepatic portal vein were very high, but were low in the jugular vein. The gut wall allows for passage of some orally administered free steroids to the liver via the hepatic portal vein. The free steroids are essentially metabolized before they reach the jugular vein, but can be recirculated via the enterohepatic route.  相似文献   

7.
Four healthy, fully conscious, 50- to 80-kg Yucatan miniature swine were fitted with carotid artery and jugular, portal, and hepatic vein catheters and hepatic artery and portal vein flow cuffs to determine transhepatic kinetics and insulin secretion. Three days later, after a 3-hour control period, the pigs were given IV sodium dichloroacetate (30 mg/kg of body weight as a bolus and 30 mg/kg/hr, as an infusion) for 6 hours. Arterial lactate concentrations decreased during the dichloroacetate infusion, but pyruvate concentrations were unaltered. The whole body rate of appearance and disappearance of glucose decreased, but plasma glucose concentrations did not change markedly. Limb skin surface temperatures increased, indicating a peripheral vasodilatory effect. Dichloroacetate had little effect on mean arterial pressure and hepatosplanchnic blood flow. Dichloroacetate may be effective as a hypolactatemic agent for lactic acidosis in pigs.  相似文献   

8.
To determine the absorption and metabolism of 17β-estradiol (E2) by the stomach and liver of the pig, crystalline E2 was placed in the stomach of prepubertal gilts. Blood samples were subsequently obtained from the hepatic portal and jugular veins and plasma was assayed for E2, estrone (E1), 17β-estradiol-glucuronide (E2G), estrone-glucuronide (E1G) and estrone-sulfate (E1S). Concentrations of E2, E1, E2G and E1S rose in the hepatic portal vein within five min and remained elevated for several hr. Concentration of E2 represented only 6% of the total estrogen detected in the hepatic portal vein during the sampling period, indicating that most of the E2 was converted or conjugated prior to entering the hepatic portal vein. The metabolism of E2 presumably occurred in the stomach mucosa because food had been withheld for 26 hr before infusion of E2. Concentrations of E2G, E1G and E1S, but not E2 and E1, rose in the jugular vein and remained elevated for several hr. The lack of a rise in E2 and E1 in the jugular vein indicates that the E2 and E1 from the hepatic portal vein were completely converted and/or removed by the liver. Most of E2 was converted to E1 and then to E1G. The infusion of bile containing normal estrogens from pregnant gilts into the duodenum of prepubertal gilts resulted in a peak of E1G and E2G in the hepatic portal and jugular veins within a few minutes. This was followed in about 180 min by a second sustained rise. The first peak was essentially abolished by extracting E1 and E2 from the bile before infusion. The second peak failed to occur in gilts given antibiotics orally to reduce gut bacteria before infusion of bile.  相似文献   

9.
Twelve horses of various breeds and either sex were anesthetized with xylazine and ketamine injected into a median or lateral thoracic vein. During anesthesia, with the horse in sternal recumbency, a 14-gauge, 8.9 cm catheter was inserted into each jugular vein by using aseptic technique. Guaifenesin in water (100 mg/kg or a maximum dose of 50 grams) was infused into one jugular vein and an equal volume of 0.9% saline solution was infused into the other jugular vein. Seven horses received 10% guaifenesin, and five horses received 5% guaifenesin. The catheters were removed before the horses recovered from anesthesia. The horses were euthanatized approximately 48 hours later, and the jugular veins were removed for histologic examination. Adherent thrombus material was observed in all veins exposed to 10% guaifenesin and in one vein exposed to 5% guaifenesin. No evidence of thrombus was observed in four veins infused with 5% guaifenesin or in those infused with saline solution. These findings are of particular significance with horses at increased risk for thrombosis or thrombophlebitis.  相似文献   

10.
Introduction:  We evaluated the totally implantable subcutaneous vascular access port (VAP) in 16 cancer patients undergoing intermittent chemotherapy for more than 30 months.
Methods:  Ports were surgically placed (The CompanionPort, Norfolk Vet Products, Skokie, Illinois 60076) in the jugular vein of 12 dogs and 4 cats between 1/2002 and 7/2004. Body weight determined polyurethane catheter size (4, 5, 7 fr.). The polysulfone port, surrounded by titanium, was anchored to subcutaneous tissue in the dorsolateral neck and confirmed with C‐arm fluoroscopy. All blood samples were obtained via VAP. Nine anticancer agents, other medications, crystalloids/colloids, and whole blood were administered. Ports were flushed every 4–5 weeks with heparinized saline solution (100 IU/ml). Removed catheters were submitted for bacteriology.
Results:  Seven of 16 animals are still alive. VAP were used for 1.5 to more than 30 months with 4–60 injections/port. Catheter tips were visualized from the left atrium distally into the caudal vena cava. Adverse events included post‐operative subcutaneous bruising and/or hematoma (4/16), difficult aspiration (4/16), catheter malposition (1/16), positional flushing (1/16), and occlusion requiring replacement (1/16). No thrombus formation or extravasation was evident. Bacterial colonization without signs of septicemia was observed in 3/4 catheters.
Conclusions:  VAP are an effective way of achieving long‐term venous access in the dog and cat. Complications are typically minor and infrequent.  相似文献   

11.
Long-term jugular vein catheterization in horses   总被引:1,自引:0,他引:1  
The use of soft catheter materials in large-bore veins has allowed safe long-term venous access in human patients. Similar principles were applied to groups of horses; the jugular vein was catheterized for 14 days (group 1) and for 30 days (group 2). Three catheter materials were compared, and the clinical and histologic findings indicated that the least reaction was associated with silastic, followed by polyurethane; polytetraflouroethylene caused marked reaction. Our results suggest that by using catheters made of materials (especially silastic) that are less stiff or rigid, the duration of catheterization can be increased to 14 days or longer with minimal complications.  相似文献   

12.
A modified catheterization and para-aminohippurate dye dilution technique was used to measure portal and hepatic blood flows in sheep. Blood flows (mean +/- 1SD) for 7 healthy sheep were 1.54 +/- 0.71 L/min and 1.98 +/- 0.75 L/min for portal and hepatic flows, respectively. Blood flow measurement was facilitated when dye injection rates produced blood para-aminohippurate acid concentrations greater than 15 mg/L. Uniform mixing of dye with blood was confirmed in 1 sheep with 2 portal vein catheters. Surgery to place the catheters was facilitated by using a ventral para-costal approach. Blood gas analysis was useful in confirming the placement of the catheters. Useful catheter life in this experiment was 41 days, which was longer than in previous reports. Treating the catheters with an organo-silane preparation, protecting the catheters against dislodgement, and use of a belly bandage to minimize damage to the external parts of the catheter may have prolonged catheter life in this experiment.  相似文献   

13.
OBJECTIVE: To quantify glutamine use in viscera drained by the portal vein in neonatal calves and to assess the relative nutritional importance of glutamine, glucose, and acetate for enterocytes. ANIMALS: 5 healthy neonatal calves. PROCEDURE: A femoral artery, jugular vein, and the portal vein were surgically cannulated in each calf. Blood flow in the portal vein was measured by use of an ultrasonographic transit-time flow probe. A series of solutions was infused on 4 days for each calf. On the infusion days, acetate, glucose, glutamine, and saline (0.9% NaCl; control) solutions were administered IV during 1-hour periods via the jugular vein. Venous and arterial blood samples were collected during the last 15 minutes of each 1-hour infusion. RESULTS: Uptake of glutamine and glucose by viscera drained by the portal vein was 0.3+/-1.1 and 1.9+/-3.1 micromol/kg0.75/min, respectively, during saline infusion. During acetate, glucose, and saline infusions, glucose was a greater source of energy for the intestines than was glutamine. However, during glutamine infusion, uptake of glutamine by viscera drained by the portal vein increased significantly (29.9+/-11.2 micromol/kg0.75/min), which was associated with an increase in ammonia production (7.0+/-0.5 micromol/kg0.75/min). Toxicosis was not associated with IV administration of glutamine. CONCLUSION: Glutamine infusion resulted in an increase in glutamine uptake by viscera drained by the portal vein, which was associated with an increase in ammonia production and a slight increase in oxygen consumption. CLINICAL RELEVANCE: These solutions may be used to develop treatments that enhance healing of intestines of diarrheic calves.  相似文献   

14.
Carbodox (CX), an antimicrobial agent, was fed at 0 or 58 ppm in a 19.5% crude protein corn-soybean metal diet to young pigs (12 to 15 kg). Radiolabeled chenodeoxycholic acid (CDC) was infused into the hepatic portal vein; after each of the subsequent six meals, blood samples were collected from the anterior vena cava (VC) and the hepatic portal (HP) veins. For the first 5 min after CDC infusion, the level of radioactivity in the CX pigs was significantly lower in the HP plasma and the slopes of the two curves of the plasma activity for the first hours were significantly different. The plasma bile acid concentrations (as measured by radioactivity) were significantly higher in the CX-treated animals following all meals. The biological half-life of CDC was 6.4 d in the controls and 5.7 d in the CX pigs. The increased rate of excretion was significant. These data indicate that bile acid metabolism in the young pig was significantly affected by feeding a subtherapeutic level of the antimicrobial CX.  相似文献   

15.
A diet consumed by pigs provides the nutrients for the production of a large number of metabolites that, after first‐pass metabolism in the liver, circulate systemically where they may exert diverse physiologic influences on pigs. So far, little is known of how feeding elicits changes in metabolic profiles for growing pigs. This study investigated differences in plasma metabolites in growing pigs at several intervals after feeding using the technique of metabolomics. Ten barrows (22.5 ± 0.5 kg BW) were fed a corn‐soybean meal basal diet and were kept in metabolism crates for a period of 11 days. An indwelling catheter was inserted into the jugular vein of each pig before the experimental period. Plasmas before and 1, 4, and 8 hr after feeding were collected at day 11 and differential metabolites were determined using a metabolomics approach. Direct comparison at several intervals after feeding revealed differences in 14 compounds. Identified signatures were enriched in metabolic pathways related to linoleic acid metabolism, arginine and proline metabolism, lysine degradation, glycine, serine and threonine metabolism, and lysine biosynthesis. These results suggest that plasma metabolites of growing pigs after feeding were modulated through changes in linoleic acid metabolism and amino acid metabolism.  相似文献   

16.
This study was designed to monitor lipid profile in the portal and hepatic blood of cows with fasting-induced hepatic lipidosis, and to compare the results with those in the jugular blood. The work was also carried out to investigate bile acid (BA) in these vessels, and further to investigate BA extraction rate in the liver. Five cows were equipped with catheters in the portal, hepatic and jugular veins (day 0), fasted for 4 days (day 1-day 4) and then refed (day 5-day 11). Before morning feeding, blood was sampled before, during and after fasting from the catheterized vessels. In the portal blood, the concentration of non-esterified fatty acids (NEFA) showed a progressive increase and at day 5 there was an approximate twofold rise. Increased NEFA concentrations were also found similarly in the other two veins. At day 5, beta-hydroxybutyrate (BHBA) in the portal, hepatic and jugular blood rose to 197, 190 and 186% of the pre-fasting value, respectively. However, the concentrations of NEFA and BHBA in the three veins gradually returned to pre-fasting concentration during the refeeding period. Compared with the pre-fasting value at day 0, the content of liver triglyceride (TG) increased significantly at day 5 (P < 0.01). In the liver, the hepatic extraction rate of BA dropped from 3.1 times pre-fasting to 2.2 times during fasting. There were no significant differences in the concentrations of glucose, TG, total cholesterol, cholesterol esters, free cholesterol and phospholipids. The results of the current study show that metabolic alterations occur in the portal, hepatic and jugular veins during induction of hepatic lipidosis in cows, and mostly metabolites, with exception of BA concentration, run parallel. The decreased BA extraction rate in the liver of fasted cows was considered to reflect hepatic cell impairment caused by TG accumulation. Hopefully, the findings, at least in part, contribute to the explanation of the pathophysiology of hepatic lipidosis in dairy cows.  相似文献   

17.
脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON),又名呕吐毒素,是目前全球谷物污染最严重的真菌毒素之一。在所有的易感动物中,以猪最为敏感。本研究选用10头健康阉公猪,随机分为2组,染毒组和对照组,染毒组经乳静脉注射DON,注射剂量为75μg/kg体重,对照组经乳静脉注射生理盐水。注射完成后开始计时30 min后放血宰杀,迅速取肝脏,采用链霉菌抗生物素蛋白—过氧化物酶连接结(streptavidin-perosidase,SP)法定位肝组织中的DON。SP法定位结果显示,在染毒组肝门管区小叶间静脉的血管壁有DON的分布。本研究采用SP法定位DON在猪体内消化器官组织的分布情况,为毒素的残留研究提供依据。  相似文献   

18.
对12头泌乳奶山羊建立代谢调控模型的外科手术及术后护理方法进行了研究。采用了一套改进的手术方法对试验羊进行肠系膜上静脉、肠系膜下静脉和门静脉插管,以及颈动脉皮肤包埋游离术来建立模型。术后8头羊所插的导管平均保持畅通2个月左右,2头羊保持畅通40 d左右,还有2头羊被淘汰。采用的改进手术方法有效地降低了建模的难度,并提高了建模的成功率,从而为动物营养代谢研究提供了有力保障。  相似文献   

19.
Chronic cannulas were placed in the hepatic portal vein, ileal vein, and carotid artery in seven crossbred growing gilts trained to consume once daily 1.2 kg of a 16% CP corn-soybean meal diet. Eleven days after surgery, each pig (37.4 kg BW) was placed in an open-circuit calorimeter and its cannulas were connected to a system for determining portal absorption of nutrients. The whole-animal heat production and net portal absorption of gut VFA were measured simultaneously for 12 h after the pig was fed 1.2 kg of feed. Plasma concentrations of VFA, including acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids, in portal and arterial samples were determined by gas chromatography after a cleanup by ion-exchange chromatography. The net portal absorption of VFA was calculated by multiplying the porto-arterial plasma concentration difference of the VFA by portal vein plasma flow. Plasma flow was estimated by the indicator-dilution technique using p-aminohippuric acid as the indicator. The energy value of absorbed VFA was the sum of products of each individual VFA multiplied by its corresponding value of the heat of combustion. The mean hourly energy value of absorbed VFA during the 12-h postprandial period was .65 +/- .03 kcal.h-1.kg BW-1. The mean hourly whole-animal heat production was 2.70 +/- .04 kcal.h-1.kg BW-1. Thus, in our 37.4-kg pigs, which were trained to consume 1.2 kg of a 16% CP corn-soybean meal diet once daily, the gut VFA absorbed into the portal vein could contribute 23.8 +/- 1.1% to whole-animal heat production if all of the absorbed VFA were combusted to CO2.  相似文献   

20.
The objective of the present study was to evaluate the potential immunological benefit of adding menhaden fish oil to the diet of weaned pigs. Twenty-four crossbred male pigs were weaned at approximately 18 days of age and placed on a complex nursery diet containing 30% lactose and 7% plasma protein with 6% corn oil as the fat source (Cont, n=12) or with 5% menhaden fish oil and 1% corn oil as the fat source (MFO, n=12) for a period of 15 days. Body weights did not differ (P>0.78) between dietary groups either at the beginning or end of the 15 days feeding period. On day 15, all pigs were non-surgically fitted with an indwelling jugular catheter. On d 16, pigs received an i.v. injection of either saline (n=6/dietary group) or lipopolysaccharide (LPS; 150 μg/kg body weight; n=6/dietary group) and blood samples were collected at 30 min intervals for a period of 5 h. Serum was harvested and stored at −80 °C for analysis of cortisol (CS), corticosteroid-binding globulin (CBG), tumor necrosis factor-alpha (TNF-) and interferon-gamma (IFN-γ). There was no significant effect of diet on basal concentrations (Time 0) of any of the blood parameters analyzed. A Time×Treatment×Diet interaction (P<0.03) was observed for serum CS such that those pigs which consumed the MFO diet followed by LPS treatment had a reduced CS response as compared to the LPS-treated pigs on the Cont diet. A Time×Treatment interaction (P<0.01) was observed for serum CBG such that LPS treatment reduced circulating CBG as compared to the saline-treated pigs. Time×Treatment×Diet interactions were also observed for serum concentrations of TNF- (P=0.084) and IFN-γ (P=0.022) such that both the TNF- and IFN-γ response to the LPS challenge was lower in those pigs receiving the MFO diet as compared to the LPS-treated pigs on the Cont diet. Overall, serum CS was negatively correlated with the CBG response (r=−0.40, P<0.001), however, the strongest negative correlation was observed in the LPS-treated pigs which consumed the MFO diet (r=−0.63, P<0.001). While further studies are needed to evaluate the immunological response of including MFO in the nursery pig diet, the present study demonstrates that supplementation with MFO does indeed alter the immunological response to an LPS challenge.  相似文献   

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