Biomedical subjects

T Hölzenbein

Publications and source records attributed to T Hölzenbein.

At least 19 recordsLinked to original sources

PubMed2005

Thiazolidinediones inhibit proliferation of microvascular and macrovascular cells by a PPARgamma-independent mechanism.

AIMS/HYPOTHESIS: This study evaluated the hypothesis that peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists, including thiazolidinediones (TZDs) and the rexinoid LG100268 (LG), directly affect human vascular cell function (proliferation, cell cycle, protein expression, lactate release) independently of (1) their PPARgamma-activating potential and (2) the cells' vascular origin. METHODS: Human umbilical vein endothelial cells (HUVECs), human adult vein endothelial cells (HAVECs), human retinal endothelial cells (HRECs) and human retinal pericytes (HRPYCs) were incubated (48 h) with 2-50 micromol/l rosiglitazone (RSG), RWJ241947 (RWJ), pioglitazone (PIO), troglitazone (TRO), 15-deoxy-Delta(12,14)-prostaglandin J2 (PGJ2) and LG. Proliferation, cell cycle distribution, protein expression, peroxisome proliferator-activated receptor responsive element (PPRE) transcriptional activity and mitochondrial effects were determined by [3H]thymidine incorporation, FACS analyses, western blots, reporter assays and lactate release respectively. RESULTS: In HUVECs, RSG, RWJ, PIO, TRO, PGJ2 and LG reduced (p<0.01) proliferation (due to a G0/G1 cell cycle arrest) by up to 23%, 36%, 38%, 86%, 99% and 93% respectively. The antiproliferative response was similar in HRPYCs and HAVECs, but was attenuated in HRECs. Whereas p21WAF-1/Cip1 and p27Kip were differently affected in HUVECs, all agents reduced (p<0.05) expression of cyclins (D3, A, E, B), cyclin-dependent kinase-2 and hyperphosphorylated retinoblastoma protein. The rank order of the antiproliferative effects of TZDs in HUVECs (RSG approximately PIO approximately RWJ<TRO) contrasted their PPRE transcriptional activities (TRO<PIO<RSG<RWJ), but correlated with cellular lactate release. Proliferation inhibition and lactate release were mimicked by rotenone (mitochondrial complex I inhibitor). CONCLUSIONS/INTERPRETATION: In conclusion, this study suggests that the antiproliferative action of the TZDs in vascular cells is independent of their PPARgamma-activating and associated insulin-sensitising potential, but could relate to mitochondrial mechanisms.

Adult↗

PubMed2004

["Abdominal dressing" - a new method of treatment for open abdomen following secondary peritonitis].

INTRODUCTION: Treatment of open abdomen following secondary peritonitis is a challenge for surgery and intensive care units (ICU). The aim of this study was to compare three different concurrent treatment strategies. METHODS: Patients suffering an open abdomen following surgery for secondary peritonitis at the Department of General Surgery from 01/01 to 12/03 were investigated. Factor studied: duration of open abdomen, incidence of multi-organ failure, need for surgical revisions, length of stay (LOS) in ICU, nursing requirements (change of dressing/day), survival and integrity of abdominal wall after discharge. Treatment strategies included: open packing (OP), classic vacuum assisted (V.A.C.(R))-therapy with silicone net protection for the intestine (CV) and V.A.C.(R)-therapy with "abdominal dressing" a newly developed meshed polyvinyl wrap (AD). RESULTS: 21 patients were studied: 5 patients were treated with OP, 8 patients with CV and 8 patients with AD. Mean LOS was 65 (OP) vs. 53 (CV) vs. 42 (AD) days (NS), peritonitis related death was 3 (OP) vs. 1 (CV) vs. 0 (AD) (p < 0.05 Chisquare test). Median nursing effort was 4 dressings/day (OP), 0.5 (CV) and 0.5 (AD) (p < 0.005 OP vs CV, AD Kruskal-Wallis test). CONCLUSION: The "abdominal dressing"-therapy seems to be a more efficient treatment option in patients suffering from open abdomen following secondary peritonitis. A trend towards shorter ICU-LOS, lower mortality rates and reduced nursing requirements support our hypothesis.

Critical Care↗

PubMed2003

The impact of endovascular stent grafting on reducing mortality rates after surgical treatment of abdominal aortic aneurysms.

OBJECTIVES: to investigate whether appropriate selection in patients with infrarenal abdominal aortic aneurysms (AAA) for transfemoral endovascular aneurysm management (TEAM) or open graft replacement (OGR) may decrease in-hospital mortality rates (MR). DESIGN: analysis of a clinical series over three periods in an university vascular center. Conclusions of the second period were drawn and prospectively applied in a third period and compared. METHODS: during the period 1989-1994 only OGR was available (n=170). In the interval 1995-2000 either OGR or TEAM were carried out (n=454). During the period 01/2001-07/2002 the conclusions concerning selection of treatment modality were drawn and prospectively applied in 132 consecutive patients. MR were recorded and possible significant differences were checked. RESULTS: during the first period MR was 6.5%. Overall MR decreased to 3.7% in the second interval. Overall MR of the last period was improved to 1.5% (p<0.05). No patient died after OGR (0% vs 6.5%, p<0.04). As all patients with significant individual risk profiles were treated by TEAM, MR slightly increased (2.9%), but the difference remained insignificant (2.4% in period 2). CONCLUSIONS: risk adjusted selection of treatment modality influences the results after OGR significantly, thereby reducing overall MR of elective AAA treatment.

Aged↗

PubMed2002

Acute phase reactants in patients with abdominal aortic aneurysm.

BACKGROUND: There is increasing evidence that an inflammatory process is present in abdominal aortic aneurysms (AAAs) to varying degrees. The aim of this study was to compare acute phase reactants in patients with asymptomatic AAA, symptomatic AAA without rupture and ruptured AAA. METHOD: Two hundred and twenty-five consecutive patients treated because of AAA were included in this case-control study. Polynomial logistic regression analysis was applied to compare admission C-reactive protein (CRP) and white blood count (WBC) measured in 111 asymptomatic outpatients, 52 symptomatic patients without rupture and 62 patients with rupture of the aneurysm. We adjusted for the potentially confounding effect of age, sex, haemoglobin levels and aneurysm diameter. RESULTS: Patients with symptomatic AAA and patients with ruptured AAA had significantly elevated CRP (p=0.002) and WBC (p<0.0001) levels compared to asymptomatic patients. There was no statistically significant difference in CRP and WBC between patients with symptomatic AAA and ruptured AAA. Median CRP values of asymptomatic, symptomatic and ruptured AAA were <0.5 (interquartile range (IQR) <0.5-0.85), 1.1(IQR <0.5-4.0) and 2.4 mg/dl (IQR 0.65-8.6), respectively, and median WBC values were 6.5 (IQR 5.5-8.0), 8.7 (IQR 6.8-11.2) and 13.2 (IQR 10.5-17.0), respectively. CONCLUSION: A significant elevation of CRP and WBC could be found in patients who presented with symptoms or rupture of an AAA. These indicators of inflammation were not observed in asymptomatic patients with AAA.

Acute-Phase Proteins↗

PubMed2002

Modulation by leptin of proliferation and apoptosis in vascular endothelial cells.

AIM: Plasma leptin concentrations not only correlate with body fat mass, but also with the degree of hypertensive retinopathy. The present study was designed to further examine, whether leptin's proliferative, proangiogenic activity relates to a yet uncovered anti-apoptotic effect. RESULTS: Leptin (10-50 nmol/l) concentration-dependently reduced apoptosis in HUVECs (human umbilical vein endothelial cells), HAVECs (human adult vein endothelial cells) and HMECs (human microvascular endothelial cells) by 20% (P < or = 0.05). These findings were supported by increased expression of the apoptosis inhibitor bcl-2 (+55%, P < or = 0.05) as well as by differential modulation of the respective cell cycle checkpoint genes/proteins p53 (-20%, P < or = 0.01), p21(WAF-1/Cip1) (-23%, P < or = 0.05) and the Retinoblastoma protein (+123%, P < or = 0.01). CONCLUSION: bcl-2 dependent anti-apoptotic action might contribute to leptin's proangiogenic activity and thereby promote the development of vascular proliferative disease in obesity.

Apoptosis↗

PubMed2001

Inferior mesenteric artery as outflow vessel in endoleaks after abdominal aortic stent-graft implantation: 36-month follow-up CT study.

The aim of this study was to determine the role of the inferior mesenteric artery (IMA) as an outflow vessel in endoleaks after abdominal aortic stent-graft implantation. Forty consecutive patients in whom abdominal aortic aneurysms (AAA) had been treated with stent-graft implantation were evaluated retrospectively. Spiral-CT examinations and angiographies up to 36 months after implantation were analyzed. In 29 (73%) of the 40 patients the IMA was perfused prior to implantation. In 5 (17%) of these 29 cases, the artery remained perfused after stent-graft insertion. In all 5 cases, endoleaks were detected; however, in none of these cases was the IMA the sole cause. In 3 of these 5 cases, angiography showed antegrade flow in the IMA. Implantation of extension stent grafts caused thrombosis of the aneurysmal sac and the IMA. There were no secondary endoleaks caused by the IMA at the 36-month follow-up examinations. The majority of IMAs which are patent prior to intervention occlude after successful stent-graft insertion. In cases with leaks and angiographically proven antegrade flow in the IMA, implantation of extension stent grafts is a therapeutic alternative to embolization. In this study, the IMA was not responsible for secondary endoleaks.

Aged↗

PubMed2001

[Inguinal hernia as a diagnostic error in ruptured groin aneurysm].

Anastomotic aneurysms observed with an incidence of 0.5% to 5.0% are considered a known complication following arterial surgery, especially when fabric grafts in the inguinal region are implanted. An anecdotal report is presented describing a 64-year old male patient, who developed, 10 years following an autologous femoro-tibial vein graft, a huge mass in the left groin. The lesion was considered an incarcerated inguinal hernia and the patient was admitted to the Department of Surgery for emergency repair. Clinical examination, duplexsonography and CT scan clarified the diagnosis of an aneurysm with a diameter of 13 cm. The aneurysm was resected, and a femoro-profundal vein graft was implanted orthotopically, the graft was covered with a sartorius muscle flap. The postoperative course was uneventful. The diagnosis is suspected by clinical examination and usually confirmed by duplexsonography. The exact etiology of suture line aneurysms is unknown; in the present case progression of the underlying arteriosclerotic arterial disease after a follow up of 10 years is likely. For the treatment the usual methods of complicated aneurysm repair and preservation of the arterial circulation--using autologous in situ methods or extraanatomic bypass grafts--with additional biologic coverage are at hand.

Aneurysm, Ruptured↗

PubMed2001

Internal iliac artery embolization before endovascular repair of abdominal aortic aneurysms: frequency, efficacy, and clinical results.

OBJECTIVE: The aim of our study was to assess the frequency, efficacy, and incidence of adverse effects of internal iliac artery embolization. MATERIALS AND METHODS: Of 343 patients examined for stent-graft repair, 147 were suitable for endovascular treatment. Fifty-five patients underwent preprocedural embolization of the internal iliac artery either unilaterally (46 patients) or bilaterally (nine patients). Successful embolization was assessed angiographically and with helical CT follow-up examinations. Colonic ischemia was ruled out clinically or colonoscopically. Buttock claudication, and sexual dysfunction in men, were evaluated through a questionnaire. RESULTS: Embolization of the internal iliac artery increased by 16% the percentage of patients for whom endovascular repair was suitable. After successful embolization in all patients, routine CT follow-up examinations after a mean time of 16.7 months showed no evidence of endoleaks related to retrograde perfusion via embolized internal iliac arteries. Nevertheless, in all patients who had undergone embolization, a primary endoleak was detected in 43.4% at the first postoperative CT examination. None of our patients had evidence of colonic ischemia. Clinical follow-up data of 46 patients were available. Of these patients, mild to severe new onset buttock claudication was found in 13 (36.1%) of 36 patients with unilateral, and in eight (80%) of 10 patients with bilateral, internal iliac artery embolization (p = 0.03). Five (25%) of 20 men had an erectile dysfunction after the procedure. CONCLUSION: Embolization of the internal iliac artery is a safe and efficient procedure that increases the applicability for endovascular repair of aortoiliac aneurysms. However, buttock claudication and erectile dysfunction are a drawback in a substantial number of patients.

Aged↗

PubMed2001

[Endovascular (transfemoral endoluminal aneurysm management; TEAM) versus conventional open therapy in abdominal aortic aneurysms (AAA): analysis of a clinical series].

All patients (n = 826) treated electively at the Department of Vascular Surgery University of Vienna, Austria, for their AAA during the years 1965-2000 were analysed with particular emphasis on endoluminal repair. Data collection was carried out in retrospect. The operative mortality or within 30 days was considered the primary endpoint of the study. Since 1995 the TEAM approach was available. From that point in time 45.5% of the AAA were treated electively in the endoluminal way. An exploratory analysis of the clinical series revealed a statistically significant difference in the incidence of various risk factors between groups in favor of open repair. Consequently a conditional regression analysis demonstrated the operative method, median patient's age (above versus below 72 years of age), reduced renal and/or pulmonary function to be of significant influence.

Aged↗

PubMed2001

[Preoperative risk factors as deciding criteria in surgical treatment strategy of infrarenal aortic aneurysm].

Significant risk factors of operative therapy in patients with infrarenal aortic aneurysms (AAA) were determined. Best treatment strategy (open surgical repair, transluminal endovascular aneurysm management (TEAM) or conservative treatment) was selected on the base of evaluated risk factors, tendency of rupture and life expectancy. Of the typical risk factors impaired renal and/or lung function showed a significant influence on hospital mortality. In patients without these significant risk factors open surgical repair leads to good clinical results. Acceptable postoperative mortality rates after elective exclusion of an AAA with average size in patients presenting significant comorbidities can only be achieved using TEAM. If TEAM can not be performed, open surgery is only justified in the case of very large AAA diameter.

Aged↗

PubMed2000

Levamisole induced apoptosis in cultured vascular endothelial cells.

To better understand the anticancer activity of Levamisole (LMS), which serves as an adjuvant in colon cancer therapy in combination with 5-Fluorouracil, this study analyses LMS' ability to induce apoptosis and growth arrest in cultured human micro- and macrovascular endothelial cells (ECs) and fibroblasts. Cells exposed (24 h) to Levamisole (range: 0.5 - 2 mmol l(-1)) alone or in combination with antioxidants (10 mmol l(-1) glutathione or 5 mmol l(-1) N-Acetylcysteine or 0.1 mmol l(-1) Tocopherol) were evaluated for apoptosis ((3)H-thymidine assays, in situ staining), mRNA/protein expression (Northern/Western blot), and proliferation ((3)H-thymidine incorporation). Levamisole dose-dependently increased apoptosis in ECs to 230% (HUVECs-human umbilical vein ECs), 525% (adult human venous ECs) and 600% (human uterine microvascular ECs) but not in fibroblasts compared to control cells (set as 100%). Levamisole increased in ECs integrin-dependent matrix adhesion, inhibited proliferation (-70%), reduced expression of survival factors such as clusterin (-30%), endothelin-1 (-43%), bcl-2 (-34%), endothelial NO-synthase (-32%) and pRb (Retinoblastoma protein: -89%), and increased that of growth arrest/death signals such as p21 (+73%) and bak (+50%). LMS (2 mmol l(-1))-induced apoptosis was inhibited by glutathione (-50%) and N-Acetylcysteine (-36%), which also counteracted reduction by Levamisole of pRb expression, suggesting reactive oxygen species and pRb play a role in these processes. The ability of LMS to selectively induce apoptosis and growth arrest in endothelial cells potentially hints at vascular targeting to contribute to Levamisole's anticancer activity.

Acetylcysteine↗

PubMed1998

An empirical study of nursing in patients undergoing two different procedures for abdominal aortic aneurysm repair.

Specialized vascular nursing has to meet the challenge presented through progress and modern developments in vascular surgery. Endovascular techniques are becoming more widespread and are now available for diseases that previously have required extensive surgery. A comparative study was carried out in two groups of patients with infrarenal abdominal aortic aneurysms (N = 50), either by means of the traditional open surgical approach or by the new endovascular stented graft technology. Four problems were compared in both groups of patients: (1) length of hospital stay, (2) dependency on nursing, (3) patients mobility after surgery, and (4) analgesic requirements. Data were obtained from a designated data sheet. Analysis of the data obtained helped us in our service to optimize the nursing process for patients undergoing major aortic surgery for open, as well as endovascular, procedures, especially regarding the nursing anamnesis and nursing diagnosis.

Activities of Daily Living↗

PubMed1997

Endoluminal stent-grafts for infrarenal abdominal aortic aneurysms.

BACKGROUND: The treatment of aortic aneurysms with endovascular stents or stent-graft prostheses is receiving increasing attention as an alternative to major abdominal surgery. To define the clinical value of this technique, we prospectively studied the use of stent-graft endoprostheses made of nitinol and covered with polyester fabric for the treatment of infrarenal abdominal aortic aneurysms. METHODS: We treated a total of 154 patients at three academic hospitals. Twenty-one patients with aortic aneurysms not involving the aortic bifurcation received straight stent-grafts, and 133 patients with aortic aneurysms involving the bifurcation and the common iliac arteries received bifurcated stent-grafts. After a unilateral surgical arteriotomy, the endoprostheses were advanced through the femoral arteries and placed under fluoroscopic guidance. Computed tomography and intraarterial angiography were performed during an average follow-up of 12.5 months. RESULTS: The primary success rate, defined as complete exclusion of the abdominal aortic aneurysm from the circulation, was 86 percent in the group receiving straight grafts and 87 percent in the group receiving bifurcated grafts. In three patients the procedure had to be converted to an open surgical operation. Minor (n=13) or major (n=3) complications associated with the procedure (including 1 death) occurred in 10 percent of the patients. All patients had a postimplantation syndrome, with leukocytosis and elevated C-reactive protein levels. CONCLUSIONS: Our results suggest that endovascular treatment of infrarenal abdominal aortic aneurysms is technically feasible and can effectively exclude abdominal aortic aneurysms from the circulation. With further refinement, endoluminal repair may emerge as an interventional strategy to treat infrarenal aortic aneurysms, especially in patients at high surgical risk.

Adult↗

PubMed1997

The first 15 months of transluminal abdominal aortic aneurysm management: a single centre experience.

OBJECTIVES: To assess the early experience with the transfemorally placed modular endovascular MinTec graft (TPEG) for abdominal aortic aneurysm (AAA). DESIGN: One single centre prospective evaluation of the endograft procedure as well as early postoperative results. SETTING: An academic teaching hospital. PATIENTS: 30 consecutive patients treated during a period of 15 months. RESULTS: Peri- and postoperative morbidity and mortality were evaluated according to the recommendations of the Ad Hoc Committee on Reporting Standards. The endograft procedure was successful in 28 patients (93.4%); two patients (6.6%) needed conversion into open conventional y-graft replacement; one patient died 36 days following intervention from multiple organ failure. Another patient died from pancreatitis unrelated to the implantation. Endoleaks were treated by "overstenting" or distal extension of the endografts, but conversions were unnecessary. Five severe adverse events were noted in four patients. CONCLUSIONS: TPEG is a feasible but technically demanding procedure, requiring both surgical techniques and catheter skills. The potential for less operative morbidity and simpler aneurysm management compared to conventional open surgery may be present. Close follow-up of patients is necessary to understand the development and treatment of endoleaks.

Aged↗

PubMed1996

Human growth hormone kinetics in critically ill patients.

Several studies have shown that exogenous human growth hormone (HGH) exerts an anabolic effect on protein metabolism in surgical patients with mild or moderate catabolism. However, contradictory results have been demonstrated in polytrauma patients where HGH did not improve protein metabolism. Aim of this study was to evaluate whether the pharmacokinetics of recombinant biosynthetic human GH (r-HGH) are altered in critically ill patients. After an overnight fast, r-HGH was infused at a rate of 460 micrograms/h/kg/bw during 120 min to five intensive care unit (ICU) patients. The patients were catabolic (nitrogen balance -11 +/- 0.5), showed normal liver function, and only one patient had a slightly impaired kidney function (creatinine > 1.5 mg/dl). Endogenous GH secretion was suppressed by continuous infusion of 50 micrograms/m2/h somatostatin. From plasma GH curves, elimination half life (t1/2kle), whole body clearance (Cltot) and steady state distribution space (DS) were calculated in an open two compartment model. Additionally, the effects of r-HGH infusion on plasma insulin, glucagon and amino acid concentrations were evaluated. T1/2kle was 19.6 +/- 2.3 min, Cltot 2.9 +/- 0.4 ml/kg/bw/min and DS 76.4 +/- 3.8 ml/kg/bw for 90 min. The plasma levels of total amino acids including the branched chain amino acids valine, leucine and isoleucine and of glutamine were significantly higher during r-HGH infusion than during the basal and somatostatin periods. In conclusion, the elimination of r-HGH in catabolic ICU patients is not different from that of healthy volunteers.

Adult↗

PubMed1995

Acute effects of insulin-like growth factor I on interorgan glucose and lactate flux in protein-catabolic dogs.

Insulin-like growth factor-I (IGF-I) is a potent protein-anabolic hormone with a glucose-lowering effect and is therefore a possible agent for treating catabolic patients. In this study we investigated the effect of recombinant human (rh) IGF-I on the interorgan flux of glucose under hypo- and normoglycemic conditions in catabolic, anaesthetized, and catheterized dogs. We administered a primed (40 micrograms/kg) continuous (1.5 micrograms.kg-1.min-1) infusion of rhIGF-I (Kabi Biopharma, Stockholm, Sweden) for 180 min together with either a saline (0.9% NaCl) or an amino acid solution (2.2 mg AA.kg-1.min-1 solution of Vamin, Kabi Nutrition, Stockholm, Sweden). RhIGF-I administration lowered plasma glucose levels for approximately 50% of the baseline (P < 0.001) and stimulated glucose uptake from skeletal muscle about twofold (P < 0.01), but did not modify glucose balances across the gut and liver. The same effects were found when infusing rhIGF-I together with AA. A co-infusion of rhIGF-I and glucose to maintain normoglycemic conditions stimulated glucose uptake from skeletal muscle by about fivefold (P < 0.001) and glucose uptake across the gut by about 50%, but reduced the hepatic glucose liberation (-65%; P < 0.01). The rhIGF-I infusion did not alter arterial lactate levels, but stimulated lactate release from skeletal muscle (P < 0.05) and lactate uptake across the liver (P < 0.05). We conclude that rhIGF-I reduces plasma glucose levels mainly by stimulating glucose uptake across skeletal muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Resistance of nitrogen metabolism to growth hormone treatment in the early phase after injury of patients with multiple injuries.

OBJECTIVES AND DESIGN: Several studies have shown an anticatabolic effect of recombinant human growth hormone (rhGH) in surgical patients. We investigated, in a prospective, randomized, double blind, and placebo-controlled study, the effect of r-hGH on hormone and nitrogen metabolism in 14 patients with multiple injuries in the early phase of injury. MATERIALS AND METHODS: All patients were treated in the intensive care unit, had mechanical ventilation, and were highly catabolic, with a mean daily nitrogen loss of 13.2 +/- 1.8 g. r-hGH was given subcutaneously (once a day, at 8 PM) in a dosage of 0.2 IU/kg.d for seven days, starting on the second day after injury. RESULTS: Administration of r-hGH evoked a significant increase in plasma concentrations of GH, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding-protein-3 (IGFBP-3). No significant differences were found for either daily or cumulative nitrogen balances (-103.1 +/- 14 g for patients receiving r-hGH and -92.1 +/- 18.1 for those with placebo). r-hGH therapy did not affect skeletal muscle extracellular water, nor did it affect plasma or muscle concentrations of total free amino acids or glutamine. Plasma albumin, prealbumin, and retinol-binding protein concentrations were also unchanged by r-hGH therapy, as were the urinary excretion of potassium and urea. CONCLUSIONS: We conclude that elevated plasma levels of GH, insulin, and IGF-I are unable to effect a protein anabolic drive in patients with multiple injuries during the early postinjury phase and assume that this r-hGH resistance to nitrogen metabolism takes place at the level distal to IGF-I.

Adult↗

PubMed1993

Acute effects of insulin-like growth factor I on inter-organ amino acid flux in protein-catabolic dogs.

The effects of acute administration of human recombinant insulin-like growth factor-I (rhIGF-I) on amino acid (AA) flux between hindlimbs, liver and gut were investigated in anaesthetized post-operative dogs. rhIGF-I produced about a 10-fold increase in plasma IGF-I concentrations above baseline values (P < 0.001), increased the plasma levels of glucagon and adrenaline (P < 0.05), and evoked a fall in plasma glucose (-55 +/- 8%; (P < 0.001) and plasma total AA levels (-23 +/- 8%; P < 0.05). AA flux in post-absorptive dogs under NaCl infusions was characterized by an efflux of AA from the hindlimbs (as a result of the protein-catabolic situation), an equal AA balance across the gut and an AA uptake by the liver. The administration of rhIGF-I increased hepatic AA uptake in the NaCl group from 3.51 +/- 0.8 to 7.5 +/- 0.4 mumol/min per kg (P < 0.01) and in the AA-infused group from 16.8 +/- 0.6 to 22.4 +/- 1.5 mumol/min per kg (P < 0.05), but did not influence the AA balance across hindlimbs and gut. Glucose infusions normalized the plasma concentrations of counter-regulatory hormones without influencing the inter-organ AA balances. We conclude that hypoaminoacidaemia caused by rhIGF-I infusions is the result of a stimulated AA uptake by the liver, but is unrelated to alterations of AA exchange across the hindlimbs.

Amino Acids↗