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Biomedical subjects

E Capristo

Publications and source records attributed to E Capristo.

At least 73 records · Page 4Linked to original sources

A surgical option for familial chylomicronemia associated with insulin-resistant diabetes mellitus.

BACKGROUND: The goal of the present work is to present an effective surgical approach for the treatment of a medically-resistant form of hyperlipidemia. METHODS: Two siblings with familial lipoprotein-lipase deficiency and subsequent hyperchylomicronemia, widespread skin xanthomas and severe insulin-resistant diabetes mellitus came to our observation after several unsuccessful attempts at medical treatment. In order to lower plasma lipids through lipid malabsorption, a modified bilio-pancreatic diversion operation was employed. The rationale in deciding to use this surgical approach was based also on the likely hypothesis that diabetes, in these subjects, was secondary to high circulating and tissue levels of lipids. Insulin sensitivity in the two treated subjects, as well as in 24 healthy volunteers constituting the control group, was assessed by euglycemic hyperinsulinemic clamp and indirect calorimetry, obtaining total end-clamp glucose uptake (M) and end-clamp glucose oxidation (ECGO) rates. RESULTS: Within 3 weeks of surgery, plasma triglycerides and cholesterol levels had decreased from 4500 and 500 mg/dl (with dietary restrictions) to lower than 450 and 150 mg/dl (on a free, lipid-rich diet) respectively. Fasting plasma glucose levels had decreased from above 300 (under daily repeated subcutaneous injections of insulin) to 80-100 mg/dl (without administration of insulin or oral hypoglycemic agents). Body weight and fat free mass were maintained in both subjects after surgery. In both patients, before surgery M and ECGO were significantly lower than in normal subjects, while after surgery they were not significantly different from normal subjects, confirming the positive metabolic effect of the operation. CONCLUSION: The surgical option used in these patients may represent an interesting and effective new possibility for treatment of those severe cases of hyperlipemia leading otherwise to metabolic complications and a low quality of life.

Adolescent↗

Xylose absorption and metabolic status in urinary intestinal orthotopic reservoir: ileocecal compared with ileal neobladder.

PURPOSE: We compare the absorption of D-xylose and vitamin B12, and the metabolic status in ileocecal and ileal orthotopic neobladders. MATERIALS AND METHODS: D-xylose plasma levels after an oral load, body composition, plasma vitamin B12, acid base and electrolyte balance were studied in 33 patients with an ileocecal reservoir and 13 patients with an ileal reservoir. Mean followup was 55 months. Results of both types of operation and a healthy control group were compared. RESULTS: Plasmic levels of D-xylose and vitamin B12 were significantly lower in the ileal reservoir than in ileocecal reservoir group and normal controls. CONCLUSIONS: Despite an acceptable body composition, intestinal malabsorption could be present in patients with an ileal reservoir but the ileocecal tract appears to be safe.

Aged↗

Reversibility of insulin resistance in obese diabetic patients: role of plasma lipids.

The aim of the present study was to measure whole body glucose uptake (M) and oxidation rate by euglycaemic hyperinsulinaemic clamp and indirect calorimetry in 7 morbidly obese subjects (BMI > 40 kg/m2) at three time points: before bilio-pancreatic diversion (BPD) surgery (Ob); 3 months after surgery POI; and after reaching stable body weight, at least 2 years after surgery POII. A group of 7 control subjects (C), matched groupwise for sex, age and BMI with POII patients, was also studied. The M value at POI was significantly higher than at Ob (49.12 +/- 8.57 vs 18.14 +/- 8.57 mumol.kg-1.min-1). No statistical difference was observed between the POII and C groups. Similarly, glucose oxidation rate was significantly increased at POI with respect to Ob (24.2 +/- 7.23 vs 9.42 +/- 3.91 mumol.kg-1.min-1) and was not significantly different between POII and C. Basal levels of non-esterified fatty acids (NEFA) decreased significantly both from Ob to POI and from POI to POII (1517.1 +/- 223.9 vs 1039.6 +/- 283.4 vs 616.0 +/- 77.6 mumol.1(-1). The same applied to basal plasma triglycerides (2.07 +/- 0.77 vs 1.36 +/- 0.49 vs 0.80 +/- 0.19 g.1(-1). Weight decreased mainly in the late postoperative period (POI to POII 124.28 +/- 11.22 to 69.71 +/- 11.78, 83% of total decrement), rather than in the early postoperative period (Ob to POI 135.25 +/- 14.99 to 124.28 +/- 11.22 kg, 17% of total decrement). We also report the clinical case of a young woman of normal weight, who underwent BPD for chylomicronaemia (secondary to familial lipoprotein lipase deficiency), whose M value, plasma insulin and blood glucose levels were normalized upon normalization of serum NEFA and triglyceride levels as determined by the therapeutic lipid malabsorption. In conclusion, in obese diabetic patients lipid malabsorption induced by BPD causes a definite enhancement of insulin sensitivity and glucose tolerance. This improvement in metabolism is noticeable before the surgery has major effects on body weight. These observations suggest that lowered plasma lipids, rather than weight loss per se, are the cause of the reversibility of insulin resistance.

Adult↗

Vitamin B12 and folic acid plasma levels after ileocecal and ileal neobladder reconstruction.

OBJECTIVES: To compare the plasma levels of vitamin B12 and folic acid following resection of ileocecal or ileal segments used for orthotopic bladder substitution. METHODS: Hemoglobin, hematocrit, and plasma levels of vitamin B12 and folic acid were measured in 34 patients with ileocecourethrostomy (ICUS) and in 16 patients with ileal reservoir (IR), with a mean follow-up of 59.8 +/- 41.9 months. The results were compared with regard to both the type of operation and the length of time since surgery. RESULTS: The level of folic acid was normal in all patients. The mean level of vitamin B12 in the ICUS group was 413.67 +/- 160.45 ng/mL compared to 257.63 +/- 121.36 for the IR group. This difference was statistically significant. In the IR group, 18.75% of the patients had a level of vitamin B12 below normal. CONCLUSIONS: There is a tendency for vitamin B12 levels to fall in patients in whom the ileum is used. Resection of the ileocecal segment including the junction does not alter the level of vitamin B12.

Aged↗

Dodecanedioic acid infusion induces a sparing effect on whole-body glucose uptake, mainly in non-insulin-dependent diabetes mellitus.

Even-numbered dicarboxylic acids (DA) have been proposed as an alternative fuel substrate in parenteral nutrition. In particular, dodecanedioic acid (C12) shows a rapid plasma clearance from tissues, a very low urinary excretion compared with other DA and a high oxidation rate. The aim of the present study was to investigate the effect of C12 infusion on insulin-stimulated glucose uptake in patients with non-insulin-dependent diabetes mellitus (NIDDM) compared with healthy volunteers. A primed-constant infusion of C12 (0.39 mmol/min) was administered over 240 min, and at 120 min a 2 h euglycaemic hyperinsulinaemic clamp was performed. Blood specimens were sampled every 30 min and fractioned urines were collected over 24 h. The levels of C12 were measured by HPLC. Indirect calorimetry was performed continuously during the entire session. Body composition was assessed in all subjects studied to obtain fat-free mass (FFM) values. Whole-body glucose uptake decreased significantly during C12 infusion in both groups, although this effect was much more evident (P < 0.01) in NIDDM patients (52.4 (SD 15.8) % decrease compared with saline) than in controls (25.9 (SD 12.1) % decrease). The M value (mumol/kgFFM per min) was reduced by C12 to lower levels in NIDDM patients than in normal controls (12.6 (SD 3.9) v. 25.9 (SD 4.5), P < 0.01). Urinary excretion of C12 over 24 h was significantly lower in NIDDM patients than in controls (4.26 (SD 0.30) mmol v. 5.43 (SD 0.48), P < 0.01), corresponding to less than 3% of the administered dose. The infusion of C12 decreased non-protein RQ significantly in both groups of patients. In conclusion, this study shows, for the first time, that C12 significantly reduces glucose uptake in both normal controls and NIDDM patients, although this sparing effect on glucose uptake is much more pronounced in diabetic patients. These data suggest that C12 decreases glucose uptake and oxidation, mainly through a mechanism of substrate competition. Thus, it might be a useful alternative substrate in enteral or parenteral nutrition, sparing glucose utilization and increasing glycogen stores, in those clinical conditions, like NIDDM, where reduced insulin-induced glucose uptake and oxidation are observed.

Blood Glucose↗

Inflammatory bowel disease: a study of the association between anxiety and depression, physical morbidity, and nutritional status.

BACKGROUND: The etiology of inflammatory bowel disease is unclear, and the role played by anxiety and depression is highly controversial. Anxiety and depression in patients with inflammatory bowel disease could be secondary to disabling symptoms, but the interaction between physical morbidity and psychologic illness in these subjects has not been sufficiently investigated. Patients with inflammatory bowel disease are nevertheless frequently undernourished, but there are no studies on the association between anxiety and depression and malnutrition. This study was designed to characterize anxiety and depression in subjects affected by inflammatory bowel disease and to establish the influence of physical morbidity and/or nutritional status on psychologic disorders. METHODS: Seventy-nine consecutive patients, 43 with Crohn's disease (CD) and 36 with ulcerative colitis (UC), were enrolled in the study. An index of the disease activity and physical morbidity was obtained by the simplified Crohn's Disease Activity Index and Truelove-Witts criteria and using the Clinical Rating Scale. Thirty-six healthy volunteers were studied as controls. All the subjects were given the State and Trait Anxiety Inventory (STAI) test and the Zung self-rating Depression Scale. RESULTS: The percentage of subjects with state anxiety was significantly higher in the CD (P < 0.001) and UC (P < 0.001) groups than in control subjects. There was no significant difference in trait anxiety among groups. The percentage of subjects with depression was significantly higher in the CD (P < 0.05) and UC (P < 0.05) groups than in control subjects. State anxiety and depression were significantly associated with physical morbidity and correlated with malnutrition in CD and UC patients. CONCLUSION: Anxiety and depression in patients with inflammatory bowel disease could be reactive to the disabling symptoms and to malnutrition. As measured with the STAI, personality trait of anxiety does not seem to play an important role in inflammatory bowel disease.

Adult↗

Differences in metabolic variables between adult coeliac patients at diagnosis and patients on a gluten-free diet.

BACKGROUND: Coeliac patients often have nutrient malabsorption with nutritional status impairment, but no report on their energy requirements is available. In this study body composition, dietary habits, basal energy expenditure, and substrate oxidation were investigated in patients with the classic form of coeliac disease. METHODS: Sixteen untreated and 18 adult coeliac patients on a gluten-free diet participated in the study. Body composition was assessed by anthropometry and bioimpedance. Energy expenditure was measured by indirect calorimetry. A food diary over 7 days was collected. RESULTS: Coeliac patients showed reduced body weight components but not a different fat-free mass percentage compared with age- and sex-matched healthy volunteers. Basal metabolic rate normalized by fat-free mass (BMR/FFM) was higher in coeliac patients than in controls. Untreated patients showed a significantly higher non-protein respiratory quotient with regard to both treated patients (P < 0.01) and controls (P < 0.05), an increased percentage of carbohydrate intake, and a good correlation between lipid faecal loss and carbohydrate oxidation (Spearman R = 0.74; P < 0.01). CONCLUSIONS: Both groups of patients had lower fat mass and FFM content than controls. The preferential carbohydrate oxidation in untreated patients might be a result of both lipid malabsorption and high carbohydrate intake.

Adolescent↗

Energy expenditure, substrate oxidation, and body composition in subjects with chronic alcoholism: new findings from metabolic assessment.

There is some controversy as to the effect of ethanol on body weight and alcohol energy contribution to body mass. The aim of this study was to evaluate the effect of alcohol addiction on resting energy expenditure (REE) and body composition. Twelve patients with current alcoholism (A) without severe liver disease or lipid and carbohydrate malabsorption were compared with a group of healthy social drinkers (B) matched for sex, age, and height. Their caloric intake was computed on the basis of a food diary. REE was measured with indirect calorimetry, and body composition was assessed by both anthropometry and bioimpedance. A significant decrease in fat mass in A compared with B was found (14.8 +/- 5.39 vs. 19.0 +/- 3.50 kg; p < 0.05). No significant differences were observed in fat-free mass (FFM) or in total body water between the two groups. A showed higher REE values normalized by FFM than B (35.5 +/- 2.97 vs. 33.0 +/- 2.95 kcal/kgFFM; p < 0.05). The nonprotein respiratory quotient was significantly lower in A than in B (0.76 +/- 0.03 vs. 0.86 +/- 0.03; p < 0.001), and A showed significantly higher lipid oxidation and lower carbohydrate oxidation than B (p < 0.05). The daily caloric intake provided only by food ingestion was found to be significantly higher in controls, but because the percentage of alcohol calories of total energy intake was 46.3 +/- 6.80 in alcoholics and 13.6 +/- 3.59 in controls (p < 0.0001), the total caloric intake, computed as food intake plus alcohol intake, was higher in alcoholics than in control subjects. No statistical differences were found in urinary nitrogen excretion and fecal loss between groups. Patients with alcoholism showed an increased REE over predicted values and a preferential lipid oxidation with respect to controls; these findings could be related to induction of microsomal ethanol oxidizing system and to mitochondrial function adaptation secondary to chronic alcohol abuse. In either case, the effects of such changes in energy metabolism may contribute to alcohol associated hepatic injury.

Adult↗

Increased resting lipid oxidation in Crohn's disease.

Resting energy expenditure (REE) was measured by indirect calorimetry and body composition was assessed by both direct (bioimpedance) and indirect (anthropometry) methods in 20 hospitalized patients with biopsy-proven ileal Crohn's disease and in a group of 16 healthy volunteers matched for sex, age, and height with the patient group. The Crohn's disease activity index was below 120 in all patients studied, who were treated with a low dose of corticosteroids (0.2-0.3 mg/kg body wt of prednisone). The average weight of Crohn's patients was significantly lower than that of controls (55.70 vs 70.50 kg, P < 0.001) due to both lower fat mass (9.97 vs 18.30 kg, P < 0.001) and lower lean body mass (45.72 vs 52.20 kg, P < 0.02). The average REE was significantly higher in the control group (1785.42 +/- 7.503 vs 1559.1 +/- 48.39 kcal/day, P < 0.001). However, these differences disappeared when REE was normalized by lean body mass (LBM) (34.49 +/- 2.56 vs 34.704 +/- 3.75 kcal/kg LBM P = NS). The nonprotein respiratory quotient was significantly lower in the patient group (0.823 +/- 0.031 vs 0.882 +/- 0.012, P < 0.025), indicating an increased lipid oxidation. This increased lipid oxidation might explain the reduced fat stores found in the group of Crohn's patients, suggesting also that a sufficiently lipid-rich diet could be useful in their nutritional management.

Adult↗

An improved GLC method for a rapid, simultaneous analysis of both medium chain fatty acids and medium chain triglycerides in plasma.

An improved gas-liquid chromatographic (GLC) method for the direct, simultaneous analysis of both medium chain monocarboxylic acids (MCFA) and medium chain triglycerides (MCT) is reported. The calibration curve of MCFA and MCT is linear in the range from 30 ng to 1000 ng. Five nanograms for tricaproin (MCT-6), 10 ng for tricaprylin (MCT-8) and 15 ng for tricaprin (MCT-9) represent the GLC detection limits of MCT, while those of MCFA range from 40 to 15 ng depending on their chain length: the longer the chain length, the higher the detection limit. The recovery of MCFA range from 79 to 99% and that of MCT from 85 to 99%. An example of plasma concentration curves of MCT and MCFA after an intravenous bolus injection of an MCT emulsion (100 mg MCT/kgbw) in a patient with Crohn's disease is shown.

Adult↗

Effects of dexfenfluramine on free fatty acid turnover and oxidation in obese patients with type 2 diabetes mellitus.

To test the potential effects of dexfenfluramine (dF) on enhancing free fatty acid (FFA) turnover and oxidation rates, 11 obese female non-insulin-dependent diabetes mellitus (NIDDM) outpatients (age, 52.5 +/- 1.5 years; weight, 81.3 +/- 3.2 kg; height, 158 +/- 3.04 cm; body mass index, 32.4 +/- 0.7 kg/m2) received a primed-constant infusion of 1-14C-palmitate. The waist to hip ratio (WHR) was 0.91 +/- 0.04. Fat body mass and lean body mass, assessed by dual-energy x-ray densitometry, were 32.0 +/- 1.5 and 49.30 +/- 2.67 kg, respectively. All patients had an average hemoglobin A1 of 6.3% +/- 0.3% in the month preceding the study and had not received oral hypoglycemic agents. Gas exchange was measured both basally and during a ventilated-hood system, indirect-calorimetry session. The protocol was a randomized, placebo-controlled, single-blind design. Subjects received dF 30 mg acutely (n = 6) or a placebo (n = 5). A dose of dF 15 mg twice daily or placebo was then administered over 15 days (chronic). To obtain serum peak level of the drug, dF was administered 2 hours before starting palmitate infusion. A free diet was allowed throughout the study, and the group treated with dF lost approximately 0.5 kg body weight. Acute and chronic dF administration resulted in a significant increase in FFA oxidation, expressed as a percentage of the dose of radiocarbon (respectively, 11.47% +/- 0.46% v 9.50% +/- 0.46% [P < .01] and 12.06% +/- 0.71% v 9.88% +/- 0.62% [P < .01]). FFA turnover rate was higher after both acute and chronic dF administration (respectively, 10.71 +/- 2.18 v 7.79 +/- 1.48 mumol/kg/min [P < .05] and 11.92 +/- 2.74 v 8.43 +/- 1.86 mumol/kg/min [P < .05]). Serum FFA concentration during both acute and chronic dF administration increased, but not significantly. Mean serum glucose level decreased after acute dF from 114.3 +/- 8.6 to 86.5 +/- 5.1 mg/dL (P < .001) and after chronic dF from 120.3 +/- 7.3 to 89.8 +/- 5.8 mg/dL (P < .001). Serum insulin was not affected by dF administration. In conclusion, oral acute and chronic dF administration increase FFA turnover and oxidation rates in NIDDM obese patients. This may play an important role in weight reduction. In addition, dF shows a weight-independent effect on glucose metabolism, reducing serum glucose levels without acting on insulin secretion.

Diabetes Mellitus, Type 2↗

Glucose-induced thermogenesis in postobese women who have undergone biliopancreatic diversion.

We evaluated the metabolic response to a standard (75-g) oral-glucose-tolerance test (OGTT) in eight post-obese women (PO) who underwent biliopancreatic diversion and in eight healthy control women (C). All subjects had been weight-stable for > or = 2 y. Blood samples for glucose, insulin, C-peptide, and nonesterified free fatty acids were taken at baseline and during 180 min after the glucose load. Plasma glucose and insulin concentrations at baseline and during the OGTT were similar in the two groups, suggesting the absence of an insulin-resistant state in the PO. Continuous indirect calorimetry was performed throughout the test. Glucose-induced thermogenesis (GIT) was higher in PO than in C (8.6 +/- 2.6 vs 4.3 +/- 1.9%; P < 0.01). These data indicate that GIT and insulin-glucose metabolism are not impaired in postobese patients when a near ideal body weight is reached and maintained after weight loss; this suggests that thermogenic deficiencies and hyperinsulinemia-insulin resistance are alterations secondary to obesity.

Adult↗

Normalization of Insulin Sensitivity in the Obese Patient after Stable Weight Reduction with Biliopancreatic Diversion.

Insulin resistance is a common feature in obese patients. To evaluate the modifications in insulin sensitivity after a bariatric operation such as Bilio-pancreatic diversion (BPD), three groups of subjects (14 normal controls (N); seven ex-obese patients (X) with at least 2 years at weight-stable conditions after BPD surgery; and eight morbidly obese patients (0)) were studied with intravenous (IVGTT) and oral (OGTT) glucose tolerance tests. The ratio of the area under the curve (AUC) for glucose over that of insulin was used as a measure of insulin sensitivity. All the following tests were conducted as Bonferroni-corrected pairwise t-tests, in case overall ANOVA was significant. No significant difference was found between N and X subjects, while obese patients showed a reduced AUCg/AUCI ratio with respect to the normal controls (O vs N: 0.01164 +/- 0.00039 vs 0.02392 +/- 0.0039, p < 0.05). IVGTT, AUCS: significant differences were found in each case: N vs X: 0.0591 +/- 0.0075 vs 0.1402 +/- 0.0399, p < 0.05; N vs 0:0.0591 +/- 0.0075 vs 0.0223 +/- 0.0031, p < 0.01; X vs 0:0.1402 +/- 0.0399 vs 0.0223 +/- 0.0031, p < 0.05. IVGTT-derived data were also analyzed using the minimal model of glucose kinetics; with this method, glucose effectiveness was significantly different between normal subject and obese subjects (0.0248 +/- 0.00288 Vs 0.00906 +/- 0.00135 per min, p < 0.001). The insulin sensitivity index was not significantly different between normal and ex-obese subjects, while both of these groups were significantly different from obese patients (N vs 0: 12.04 x 10&sup5; +/- 2.61 x 10&sup5; vs 3.29 x 10&sup5; +/- 0.61 x 10&sup5;, p < 0.066; X vs 0: 16.42 x 10&sup5; +/- 4.23 x 10&sup5; vs 3.29 x 10(1)+/- 0.61 x 10&sup5; per min per pM, p < 0.02). In conclusion, the present study indicates that, after a body weight reduction operation capable of almost re-establishing ideal body weight like BPD, obese individuals with a family history of obesity show a normalization of insulin response to glucose load.

Journal Article↗

A rapid GLC method for the direct analysis of plasma medium chain fatty acids.

A new, rapid, gas-liquid-chromatographic (GLC) method for the direct determination of plasma medium-chain fatty acids (MCFA) (from C8 to C12) which does not require derivatization procedures is described. Analysis of underivatized MCFA by GLC showed a detection limit ranging from 0.50 to 0.217 microgram depending on chain length: the longer the chain, the higher the detection limit. Compared with the HPLC and GLC methods currently described in the literature, this GLC procedure appears to be easy, adequately sensitive, accurate and well reproducible for those MCFA, like n-octanoic and n-decanoic acids, present in plasma after p.o. or i.v. MCT administration and it requires a short time (about 30 min) for complete processing.

Adult↗

Metabolic effects and disposition of sebacate, an alternate dicarboxylic fuel substrate.

Disodium sebacate is a 10-carbon-atom dicarboxylic acid, proposed as substrate for parenteral nutrition. We investigated its pharmacokinetic profile and thermogenic effect during a short-time infusion (5 h at 10 g/h) in 7 male volunteers. Sebacate in serum and urine was measured by high-performance liquid chromatography. A single-compartment model with two linear elimination routes was fitted. Metabolic measurements (VO2, VCO2, respiratory quotient, metabolic rate) were continuously performed for 8 h (5 h during and 3 h after the infusion) by a canopy indirect calorimeter. The apparent volume of distribution of sebacate was 8.39 +/- 0.69 liters, and the plasma fractional removal rate constant was 0.0086 +/- 0.00077 min-1. The average half-life and plasma clearance were 80.6 min and 72 ml/min, respectively. The increase in metabolic rate, the decrease in respiratory quotient and the changes in ketone body, glucagon and insulin levels during the infusion were not significant. 24-hour catecholamine excretion was within normal limits. Calories administered by sebacate seem to be available for utilization without relevant metabolic side effects.

Adult↗

A case of gamma-hydroxybutyric acid withdrawal syndrome during alcohol addiction treatment: utility of diazepam administration.

Gamma-hydroxybutyric acid (GHB) is an emerging drug for alcoholism therapy. We present a case of GHB withdrawal syndrome secondary to GHB addiction during alcoholism treatment. A complete disappearance of drug withdrawal syndrome was achieved with oral diazepam and the symptoms resolved without sequelae. GHB has been used for alcoholism therapy for only a few years now, but the trend is increasing, and other cases similar to this one are foreseeable. This risk could be higher in some countries in which GHB use is increasing not for alcoholism therapy, but for its euphoric and anabolic effects. The present experience indicates that administration of benzodiazepines would seem to be sufficient to achieve total regression of the withdrawal syndrome in a short time, at least if recognized early.

Administration, Oral↗

Plasma clearance and oxidation of dodecanedioic acid in humans.

BACKGROUND: Dicarboxylic acids are water-soluble, contrary to monocarboxylic acids, and have a metabolic pathway intermediate between those of lipids and carbohydrates. Our goal was to investigate the plasma turnover and oxidation rate of dodecanedioic acid (C12) in eight healthy male volunteers. METHODS: A simultaneous infusion of both cold (0.24 mmol/min corresponding to 0.396 kcal/min) and radiolabeled (1.62 microCi/min) C12 free acid was performed. Blood specimens were sampled over a period of 360 minutes, and 24-hour urine samples were collected to measure the levels of C12 by high-performance liquid chromatography and liquid scintillation. Indirect calorimetry was continuously performed, and expired 14CO2 was collected. Binding of C12 in human plasma was determined in separate experiments using equilibrium dialysis. RESULTS: A linear one-compartment model was used to describe the kinetics of labeled C12. Its volume of distribution was 139.02 +/- 10.84 mL/kgbw (mean +/- SE), and its plasma elimination constant was 0.01 +/- 0.004 min-1. The 24-hour urinary excretion of C12 was 3.14 +/- 0.96 mmol, corresponding to about 7% of the administered dose. The amount of C12 oxidized, expressed as percent oxidation, was equal to 35.44 +/- 1.64%. The mean basal value of npRQ (0.80 +/- 0.006) significantly (p < .02) decreased during the infusion to 0.78 +/- 0.01, which is a value close to that theoretically calculated (0.77). The oxidation of free fatty acids was significantly increased at the end of the C12 infusion, whereas the glucose oxidation was reduced to about 50%. CONCLUSIONS: The experimental data suggest that C12 might represent a fuel substrate immediately available for tissue energy requirements, because a relevant amount of C12 is promptly oxidized. Its prompt oxidation and its conversion to succinic acid support the use of dodecanedioic acid in parenteral nutrition, especially in insulin-resistance conditions in which glucose uptake and oxidation is impaired.

Binding Sites↗