Continuous Total Parenteral Nutrition Research Articles

Favorable inhibitory effect of clodronate on hepatic steatosis in short bowel syndrome model rats.

This study investigated the anti-inflammatory effect of clodronate, a vesicular nucleotide transporter (VNUT) inhibitor, on intestinal-failure-associated liver disease (IFALD) in a rat model of short bowel syndrome (SBS). The rats underwent jugular vein catheterization for continuous total parenteral nutrition (TPN) and 90% small bowel resection. The animals were divided into the following groups: TPN/SBS (Control group), TPN/SBS/intravenous administration of low-dose clodronate (20mg/kg twice per week; Low group), or TPN/SBS/intravenous administration of high-dose clodronate (60mg/kg twice per week; High group). On day 7, the rats were euthanized. Hepatic steatosis and hepatocellular injury were also assessed. Hepatic steatosis and lobular inflammation in the liver were observed in all groups. The High group showed histologically reduced hepatic steatosis compared with the Control group. IL-6 and Nlrp3 expression in the High group was significantly suppressed compared to that in the Control group. The expression of other inflammatory cytokines tended to be lower in the High dose group than in the control group. The lipid metabolism gene expression in the liver specimens showed no significant differences among the groups. The high-dose administration of clodronate may, therefore, inhibit hepatic steatosis and inflammation associated with IFALD in patients with SBS.

Novel Automated Self-adjusting Subcutaneous Insulin Algorithm Improves Glycemic Control and Physician Efficiency in Hospitalized Patients.

Hyperglycemia occurs in 22% to 46% of hospitalized patients, negatively affecting patient outcomes, including mortality, inpatient complications, length of stay, and hospital costs. Achieving inpatient glycemic control is challenging due to inconsistent caloric intake, changes from home medications, a catabolic state in the setting of acute illness, consequences of acute inflammation, intercurrent infection, and limitations in labor-intensive glucose monitoring and insulin administration. We conducted a retrospective cross-sectional analysis at the University of California San Francisco hospitals between September 3, 2020 and September 2, 2021, comparing point-of-care glucose measurements in patients on nil per os (NPO), continuous total parenteral nutrition, or continuous tube feeding assigned to our novel automated self-adjusting subcutaneous insulin algorithm (SQIA) or conventional, physician-driven insulin dosing. We also evaluated physician efficiency by tracking the number of insulin orders placed or modified. The proportion of glucose in range (70-180 mg/dL) was higher in the SQIA group than in the conventional group (71.0% vs 69.0%, P = .153). The SQIA led to a lower proportion of severe hyperglycemia (>250 mg/dL; 5.8% vs 7.2%, P = .017), hypoglycemia (54-69 mg/dL; 0.8% vs 1.2%, P = .029), and severe hypoglycemia (<54 mg/dL; 0.3% vs 0.5%, P = .076) events. The number of orders a physician had to place while a patient was on the SQIA was reduced by a factor of more than 12, when compared with while a patient was on conventional insulin dosing. The SQIA reduced severe hyperglycemia, hypoglycemia, and severe hypoglycemia compared with conventional insulin dosing. It also improved physician efficiency by reducing the number of order modifications a physician had to place.

Superiority of Intestinal Adaptation by Hepatocyte Growth Factor in the Jejunum: An Experimental Study in a Short-Bowel Rat Model

BackgroundWe evaluated the effect of recombinant human hepatocyte growth factor (rh-HGF) on intestinal adaptation in a rat model of short-bowel syndrome (SBS). MethodsSprague–Dawley rats underwent jugular vein catheterization for continuous total parenteral nutrition (TPN) and 90 % small bowel resection. The animals were divided into 3 groups: TPN/SBS (control group, n = 7), TPN/SBS/intravenous recombinant human hepatocyte growth factor (HGF) (0.3 mg/kg/day) (HGF group, n = 7), and TPN/SBS/intravenous c-Met inhibitor (0.3 mg/kg/day) (anti-HGF group, n = 5). On day 7, rats were euthanized and histologically evaluated. Serum diamine oxidase (S-DAO) levels were evaluated using an enzyme-linked immunosorbent assay. The nutrient transporter and glucagon-like peptide-2 (GLP-2) receptor expression were evaluated using real-time polymerase chain reaction. ResultsThe jejunal and ileal villus heights were higher and the S-DAO concentrations significantly higher (p = 0.04) in the HGF group than in the control and anti-HGF groups. The sodium-dependent glucose transporter 1 expression in the HGF group was significantly higher than in the control group and significantly suppressed in the anti-HGF group (p < 0.01). The peptide transporter 1 expression in the jejunum was higher in the HGF group than in the other groups and significantly suppressed in the anti-HGF group (p < 0.01). The GLP-2 receptor expression in the jejunum was higher in the HGF group than the other groups, and it was significantly suppressed in the anti-HGF group (p < 0.01). These jejunal results regarding nutrient transporter an GLP-2 receptor were not found in the ileum. ConclusionsThe administration of rh-HGF appears to be more effective in the jejunum than in the ileum. Type of StudyExperimental Research. Level of EvidenceN/A.

Potential mechanisms underlying the effect of hepatocyte growth factor on liver injury in short bowel syndrome model rats.

The purpose of this study was to investigate the autophagy associated with apoptosis in hepatic damage in the short bowel syndrome rat model. SD rats underwent jugular vein catheterization for continuous total parenteral nutrition (TPN) and 90% small bowel resection. Animals were divided into two groups: TPN plus SBS (Control group) or TPN plus SBS plus intravenous administration of HGF (HGF group). On day 7, the rats were harvested, and hepatocellular injury was evaluated. In an SBS rat model, hepatic steatosis and lobular inflammation were histologically suppressed in the HGF group (p < 0.01). The expression of tumor necrosis factor-α in the HGF group tend to be higher than that in the control group (p = 0.13). The gene expression of transforming Growth Factor-β in the HGF group was suppressed compared to the control group (p < 0.01). HGF treatment may have an antiapoptotic effect via the intrinsic pathway by caspase 9. Protein expressions of Rubicon (p = 0.03) and p62 (p < 0.01) in the HGF group were found to have increased compared to those in the control group. The inhibitory effect of HGF on hepatic steatosis remains unclear, and further studies focusing on the mechanisms of fat accumulation are needed.

Potential negative effect of total parenteral nutrition on the human circadian clock.

When patients cannot eat on their own, total parenteral nutrition (TPN) is a clinically beneficial method of maintaining nutrition. However, many animal studies have demonstrated that circadian rhythms are strongly affected by feeding time, raising the concern that continuous TPN around the clock may have an unexpected negative impact on the circadian clock of patients. To investigate this concern, we compared clock gene expression of aged subjects with or without TPN using hair follicle cells and found that while none of the non-TPN subjects showed any obvious defects in circadian rhythms of peripheral clock gene expression, a portion of aged subjects receiving continuous TPN showed abnormal circadian rhythms in peripheral clocks. Continuous TPN around the clock may therefore potentially perturb peripheral circadian rhythms, giving rise to the proposal that TPN needs to be administered with consideration to time factors.

The preventive effect of recombinant human hepatocyte growth factor for hepatic steatosis in a rat model of short bowel syndrome

PurposeShort bowel syndrome (SBS) patients require total parenteral nutrition (TPN) following massive small bowel resection (SBR), which may cause intestinal failure-associated liver disease (IFALD), a life-threatening complication. Hepatocyte growth factor (HGF) acts as a potent hepatocyte mitogen with anti inflammatory and antioxidant actions. The present study evaluated the effect of recombinant human HGF (rh-HGF) on SBR and subsequent IFALD using a parentally fed rat model of SBS. MethodsRats underwent jugular vein catheterization for continuous TPN and 90% SBR. They were divided into 2 groups: TPN alone (SBS/TPN group: n = 7) or TPN plus the intravenous administration of rh-HGF (0.3 mg/kg/day) (SBS/TPN+HGF group: n = 7). On day 7, their tissues and stool were harvested to evaluate the effects of HGF. ResultsRegarding the histological findings, based on the nonalcoholic fatty liver disease (NAFLD) activity score, the SBS/TPN+HGF group showed significantly less hepatic steatosis and inflammatory cell infiltration than the SBS/TPN group (NAFLD activity score, 4.00 ± 1.83 vs. 1.00 ± 0.82; p < 0.01). The SBS/TPN+HGF group showed a higher expression of Farnesoid X receptor in the liver and lower expression of Toll-like receptor 4 in the ileum than the SBS/TPN group. Regarding the composition of the bacterial gut microbiota, Actinobacteria, Bacteroidetes and Proteobacteria were decreased in the SBS/TPN+HGF group compared with the SBS/TPN group. ConclusionIn our SBS with TPN rat model, rh-HGF administration had a preventive effect against hepatic steatosis and dysbiosis. rh-HGF may therefore be a potentially effective therapeutic agent for SBS and subsequent IFALD. Type of studyExperimental research.

The administration of hepatocyte growth factor prevents total parenteral nutrition-induced hepatocellular injury in a rat model

Total parenteral nutrition (TPN) sometimes induces parenteral nutrition-associated liver disease (PNALD). Hepatocyte growth factor (HGF) acts as a potent hepatocyte mitogen anti-inflammatory and antioxidant actions. We aimed to evaluate the effect of HGF on PNALD in a rat model of TPN. A catheter was placed in the right jugular vein for 7-day continuous TPN. All rats were divided into three groups: TPN alone (TPN group), TPN plus intravenous HGF at 0.3mg/kg/day [TPN + HGF (low) group], and TPN plus HGF at 1.0mg/kg/day [TPN + HGF (high) group]. On day 7, livers were harvested and the histology, inflammatory cytokines and apoptosis were evaluated. Histologically, lipid droplets were apparent in the TPN group, but decreased in the TPN + HGF (low) and TPN + HGF (high) groups. The histological nonalcoholic fatty liver disease activity scores in the TPN + HGF (low) and TPN + HGF (high) groups were significantly lower than that in the TPN group (p < 0.01). There were no significant differences in the inflammatory cytokine levels of the three groups. The caspase-9 expression levels in the TPN + HGF (low) and TPN + HGF (high) groups were significantly decreased in comparison to that in the control group (p < 0.05). The intravenous administration of HGF attenuated hepatic steatosis induced by 7-day TPN dose dependently.

Challenges of Microvillus Inclusion Disease in the NICU.

Mutations in the myosin 5β, syntaxin-binding protein 2, and syntaxin 3 genes lead to microvillus inclusion disease (MVID), an autosomal recessive congenital enteropathy. This rare disease is characterized by lack of microvilli on the surface of enterocytes in the small intestine, the presence of pathognomonic intracellular microvillus inclusions, and vesicular bodies within these enterocytes. This pathology leads to the characteristic intractable, life-threatening, watery diarrhea. In the more common early-onset form, affected patients present in the first few days after birth, whereas in the late-onset form, clinical manifestations appear at approximately 2 to 3 months of age. Genetic testing can confirm the diagnosis, but the infant's medical history, clinical presentation, and small intestinal biopsy results are strongly suggestive of the diagnosis. The prevalence of MVID is thought to be higher in countries with a high degree of consanguinity. Patients with MVID cannot tolerate feedings and require continuous total parenteral nutrition. Mortality is extremely high in the early-onset type with reports of survival in patients treated with small intestinal transplantation. Medical counseling for parents of infants with MVID needs to reflect our current understanding of the various genetic forms of this disease, the feasible management, and anticipated outcomes.

Exogenous Secretin Improves Parenteral Nutrition-associated Liver Disease in Rats.

Intestinal failure-associated liver disease (IFALD) is a feared and life-threatening complication in neonates with intestinal failure (IF) receiving long-term total parenteral nutrition (TPN). This study aims to investigate the effect of exogenous secretin on liver pathology and hepatic function in a rat model of PN-associated liver disease (PNALD). Male Sprague-Dawley rats underwent right jugular venous catheterization to receive 14-day continuous TPN therapy. All rats were allocated into 3 groups: the Control group (n = 8) did not have surgery or TPN and was fed standard rat chow ad libitum; the TPN group (n = 8) underwent catheter insertion and TPN treatment; and the TPN/S group (n = 8) also underwent catheter insertion, TPN treatment, and exogenous secretin treatment (2.5 nmol · kg · day) daily. Fourteen days after initial surgery, we collected the animals' liver and blood samples for further test. The TPN/S group had diminished direct bilirubin (TPN, 2.1 ± 0.7 μmol/L; TPN/S, 1.5 ± 0.2 μmol/L) and liver total bile acid levels (TPN, 144.5 ± 21.2 μmol/L; TPN/S, 123.4 ± 10.4 μmol/L) and improved histological outcomes compared with those in the TPN group. Exogenous secretin also enhanced the canalicular transporter (BSEP, 0.5-fold, P = 0.011) and inhibited the basolateral transporter (OSTA, -0.48-fold, P = 0.002; OSTB, -0.6-fold, P = 0.013) of liver bile acid. In this animal model of PNALD, secretin may improve cholestasis by enhancing canalicular transport, inhibiting the basolateral export of liver bile acid, and eventually decreasing the total bile acid level in the liver. Exogenous secretin treatment may potentially prevent and treat IFALD in IF patients relying on long-term TPN therapy.

Continuous low-dose fructose infusion does not reverse glucagon-mediated decrease in hepatic glucose utilization

An adaptation to continuous total parenteral nutrition (TPN; 75% of nonprotein calories as glucose) is the liver becomes a major consumer of glucose with lactate release as a by-product. The liver is able to further increase liver glucose uptake when a small dose of fructose is acutely infused via the portal system. Glucagon, commonly elevated during inflammatory stress, is a potent inhibitor of glucose uptake by the liver during TPN. The aim was to determine if continuous fructose infusion could overcome the glucagon-mediated decrease in hepatic glucose uptake. Studies were performed in conscious, insulin-treated, chronically catheterized, pancreatectomized dogs that adapted to TPN for 33 hours. They were then assigned to 1 of 4 groups: TPN (C), TPN + fructose (4.4 μmol kg −1 min −1; F), TPN + glucagon (0.2 pmol kg −1 min −1; GGN), or TPN + fructose and glucagon (F + GGN) for an additional 63 hours (33-96 hours). Insulin, fructose, and glucagon were infused into the portal vein. During that period, all animals received a fixed insulin infusion of 0.4 mU·kg −1·min −1 (33-96 hours); and the glucose infusion rates were adjusted to maintain euglycemia (6.6 mmol/L). Continuous fructose infusion was unable to further enhance net hepatic glucose uptake (in micromoles per kilogram per minute) (31.1 ± 2.8 vs 36.1 ± 5.0; C vs F), nor was it able to overcome glucagon-mediated decrease in net hepatic glucose uptake (10.0 ± 4.4 vs 12.2 ± 3.9; GGN vs F + GGN). In summary, continuous fructose infusion cannot augment liver glucose uptake during TPN; nor can it overcome the inhibitory effects of glucagon.

Juvenile polyposis of the stomach—a novel cause of hypergastrinemia

A 38-year-old female presented with a 3-year history of postprandial abdominal pain, refractory nausea, vomiting and hematemesis. She appeared malnourished and her symptoms were refractory to previous treatment with acid-suppressive drugs, prokinetics and antiemetics. Her medical history was significant for a diagnosis of juvenile polyposis syndrome at the age of 14 resulting in a transverse colectomy, and a diagnosis of Crohn's disease in her residual colon at the age of 35 resulting in a total colectomy. Physical examination, blood analysis, esophagogastroduodenoscopy with biopsy, abdominal endoscopic ultrasound, abdominal CT scan, MRI, 24 h urine analysis, MIBG scintigraphy, ocreotide scintigraphy, fluorodeoxyglucose-PET scan and genetic testing for defined polyposis syndromes (SMAD4, BMPR1A). Juvenile polyposis syndrome with outlet obstruction of the stomach and excessive hypergastrinemia. Continuous acid-suppressive therapy, prokinetic therapy and total parenteral nutrition. Repetitive endoscopic polypectomy (also known as debulking) was performed twice and was followed by gastrectomy with duodenoesophageal anastomosis.

Pancreatic-induced Intramural Duodenal Haematoma

Spontaneous intramural duodenal haematoma (IDH) is an uncommon pathology and it is usually related to anticoagulant therapy. Other causes include various pancreatic diseases, connective tissue disease, peptic ulcer disease and pancreaticoduodenal aneurysm. IDH of pancreatic origin has been infrequently reported. The disease course can be life-threatening and serious complications may occur, including gastric outlet obstruction, duodenal perforation and septicaemia. A case of pancreatic-induced IDH is presented, for which pancreaticoduodenectomy was performed as definitive treatment. In general, medical treatment with continuous nasogastric aspiration and total parenteral nutrition is recommended as initial management strategy. Surgical interventions (evacuation of blood clot or surgical resection) are reserved for patients in whom medical treatment fails or complications occur.

Insulin Management of Diabetic Patients on General Medical and Surgical Floors

To review the standardized subcutaneous insulin protocols for diabetic patients on general medical and surgical floors at the University of Vermont. Insulin protocols were developed for inpatients eating regular meals, and those receiving continuous tube feedings or total parental nutrition. The recommended starting subcutaneous insulin protocol for patients receiving meals is a basal-bolus approach using 0.5 U/kg basal insulin (glargine once daily, or neutral protamine Hagedorn [NPH] twice daily) and 0.1 U/kg rapid analog at each meal (lispro, aspart, or glulisine) for the average patient. The dose of basal is lowered by 0.2 U/kg for medical conditions with a high sensitivity to insulin or that have an added risk for hypoglycemia (renal or hepatic impairment, thin or normal weight, elderly, frail, hypothyroidism, adrenal insuffi ciency, etc.). Alternatively, an extra 0.2 U/kg basal is given for states of presumed high insulin resistance such as marked obesity with metabolic syndrome, open wounds, infections, etc. In turn, patients receiving continuous tube feedings receive the same 24-hour insulin doses (0.6-1.0 U/kg) in divided doses of premixed 70/30 (NPH/regular) insulin every 8 hours. This program allows lowering or eliminating 1 of the doses for the increasingly common tube-feeding programs in rehabilitation centers or patients' homes that entail discontinuation of tube feeding for 6 to 8 hours. A variation on this approach is used with total parenteral nutrition (TPN), with a portion of the insulin placed in the TPN bag and the remainder given as "q 8 hour 70/30" insulin. Starting insulin doses for all of the programs are adjusted daily to attain inpatient blood glucose goals of <110 mg/dL fasting and 110 to 180 mg/dL throughout the day. Standardized protocols have been developed and implemented at the University of Vermont for patients receiving regular meals and continuous tube feedings or TPN.

Onset of Small Intestinal Atrophy Is Associated with Reduced Intestinal Blood Flow in TPN-Fed Neonatal Piglets

Our aim was to determine the speed of onset of total parenteral nutrition (TPN)-induced mucosal atrophy, and whether this is associated with changes in intestinal blood flow and tissue metabolism in neonatal piglets. Piglets were implanted with jugular venous and duodenal catheters and either a portal venous or superior mesenteric artery (SMA) blood flow probe. At 3 wk of age, piglets were randomly assigned to receive continuous enteral formula feeding (n = 8) or TPN (n = 17) for 24 or 48 h. Blood flow was recorded continuously and piglets were given an i.v. bolus of bromodeoxyuridine and (13)C-phenylalanine to measure crypt cell proliferation and protein synthesis, respectively. After 8 h of TPN, portal and SMA blood flow decreased 30% compared with enteral feeding (P < 0.01), and remained near levels of food-deprived piglets for the remaining 48 h of TPN. After 24 h, TPN reduced jejunal inducible nitric oxide synthase (iNOS) activity and protein abundance (P < 0.05), small intestinal weight, and villous height (P < 0.01) compared with enterally fed piglets. Cell proliferation and DNA mass were decreased (P < 0.05) and apoptosis increased (P < 0.05) after 48 h of TPN. Protein synthesis was lower (P < 0.05) after 24 h of TPN, and protein mass was lower (P < 0.05) after 48 h of TPN, compared with enteral feeding. These data indicate that the transition from enteral to parenteral nutrition induced a rapid (<8 h) decrease in intestinal blood flow, and this likely precedes villous atrophy and the suppression of protein synthesis at 24 h, and of cell proliferation and survival at 48 h.

The Influence of l-Glutamine on the Depression of Hepatic Cytochrome P450 Activity in Male Rats Caused by Total Parenteral Nutrition

Total parenteral nutrition (TPN) bypasses the gut leading to intestinal and hepatic dysfunction, including decreased hepatic cytochrome P450 (P450) activity. Glutamine prevents the TPN-associated changes in gut function and morphology. This study examined the effect of glutamine supplementation on hepatic P450 activities in male Sprague-Dawley rats receiving continuous TPN. Animals received continuous lipid-free TPN for 7 days with 0, 0.1, or 4.5% glutamine. Surgical controls were allowed free access to rat chow. The V(max)/K(m) ratios (intrinsic clearance) for the formation of 4-hydroxymidazolam (CYP3A) were 12.8, 14.6, and 27.7 microl/min/mg for TPN treatment with 0, 0.1%, or 4.5% glutamine, respectively, compared with a chow-fed control (37.1 microl/min/mg). The corresponding values for 1'-hydroxymidazolam formation (CYP3A) were 3.7, 6.1, 11.7, and 15.2 microl/min/mg, respectively. The addition of glutamine to TPN similarly affected the formation rates for 2beta- and 6beta-hydroxytestosterone (CYP3A), and these metabolite formation rates were highly correlated (r = 0.865; p < 0.001). The formation rates for 2alpha- and 16alpha-hydroxytestosterone (CYP2C) were also highly correlated (r = 0.892; p < 0.001). Parenteral glutamine modified the TPN-associated suppression of CYP3A and CYP2C activities in adult male rats receiving TPN.

Ligation of a patent ductus arteriosus under fentanyl anesthesia improves protein metabolism in premature neonates

Background/Purpose: Although surgical ligation effectively reverses the cardiopulmonary failure associated with patent ductus arteriosus (PDA), previous findings have suggested that such surgery itself elicits a catabolic response in premature neonates. Therefore, the authors sought to quantitatively assess whether PDA ligation under fentanyl anesthesia aggravated or improved the protein metabolism of premature neonates. Methods: Seven ventilated, premature neonates (birth weight 815 ± 69 g) underwent PDA ligation with standardized fentanyl anesthesia (15 μg/kg) on day-of-life 8.4 ± 1.2 and were studied immediately pre- and 16 to 24 hours postoperatively while receiving continuous total parenteral nutrition (TPN). Whole-body protein kinetics were calculated using intravenous 1-[13C]leucine, and skeletal muscle protein breakdown was measured from the urinary 3-methylhistidine to creatinine ratio (MH:Cr). Results: Whole-body protein breakdown (10.9 ± 1.2 v 8.9 ± 0.8 g/kg/d, P <.05), turnover (17.4 ± 1.2 v 15.4 ± 0.8 g/kg/d, P <.05), and MH:Cr (1.95 ± 0.20 v 1.71 ± 0.16 μmol:mg, P <.05) decreased significantly after operation. This resulted in a 60% improvement in protein balance (1.6 ± 0.8 v 2.6 ± 0.6 g/kg/d, P = 0.08) postoperatively. Conclusions: Because of decreased whole-body protein breakdown, whole-body protein turnover, skeletal muscle protein breakdown, and increased protein accrual, surgical PDA ligation under fentanyl anesthesia promptly improves the protein metabolism of premature neonates enduring the stress of a PDA. J Pediatr Surg 35:1277-1281. Copyright © 2000 by W.B. Saunders Company.

Bolus Intravenous Infusion of Amino Acids or Lipids Does Not Stimulate Gallbladder Contraction in Neonates on Total Parenteral Nutrition

Stimulation of gallbladder contraction in patients receiving total parenteral nutrition (TPN) may be beneficial in preventing cholestatic jaundice associated with TPN. Bolus intravenous administration of either amino acids or fat promotes gallbladder contraction in normal adult volunteers after a period of starvation. This phenomenon has not been investigated in patients receiving continuous TPN. The aim of this study was to test the hypothesis that bolus intravenous infusion of amino acids or fat produces gallbladder contraction in neonates receiving TPN. Methods: Twentyeight studies of gallbladder contraction were performed in 18 neonates receiving continuous TPN (median weight, 2.3 kg; range, 1.3 to 7.3; gestational age, 37 weeks; range, 28 to 40; age, 6.5 days; range, 2 to 180). Different types of experiments were performed: (1) bolus intravenous infusion of amino acid or fat for 60 minutes at twice the normal infusion rate; (2) bolus intravenous infusion of amino acid or fat for 15 minutes at four times the normal infusion rate. Gallbladder volume was measured by real‐time ultrasonography by a single investigator. Measurements were made before starting the bolus infusion and every 15 minutes for 1 hour. Results: The volume of the gallbladder before bolus intravenous infusion was not significantly different between experiments (median, 985; range, 603 to 1,802 mm3). These volumes are consistent with an enlarged and atonic gallbladder as previously reported in infants receiving parenteral nutrition. In all experiments there was no significant decrease in gallbladder volume after bolus infusion of either amino acids or fat. Conclusions: Contrary to their effects in adults, bolus infusions of amino acids or fat did not induce gallbladder contraction in neonates on TPN. This may have been because of lack of starvation in the neonates and/or the effect of continuous glucose infusion.

Discontinuous total parenteral nutrition prevents postischemic mitochondrial dysfunction in rat liver.

Although discontinuous total parenteral nutrition (d-TPN) has recently been favored for clinical use over continuous total parenteral nutrition (c-TPN) to ameliorate liver dysfunction, mechanisms for the protection against postoperative liver dysfunction remain unknown. This study aimed to examine differences in mitochondrial function in d-TPN- and c-TPN-pretreated livers during ischemia-reperfusion. Rat livers pretreated with d-TPN or c-TPN were perfused with Krebs-Ringer buffer and were exposed to 25% low-flow hypoxia followed by reperfusion. Intrahepatic mitochondrial membrane potential (triangle up) and cell viability were assessed by dual-color digital microfluorography using rhodamine 123 (Rh123) and propidium iodide (PI), respectively. In response to hypoxia, livers pretreated with c-TPN, d-TPN, and an ordinary chow diet exhibited a significant triangle up reduction among the entire lobules. Upon reperfusion, the regional triangle up values further decreased in the c-TPN liver, whereas those in the d-TPN-treated or chow-treated livers displayed a rapid recovery toward the control levels. The severity of cell injury did not differ among the groups, showing that the reperfusion-induced triangle up drop in the c-TPN-pretreated liver is not a consequence of cell injury. Differences in the triangle up drop among the groups appear to occur irrespective of those in the glycogen storage, because the livers undergoing d-TPN display a marked triangle up recovery even when reperfused at the end of a fasted state. These results indicate that c-TPN, but not d-TPN, jeopardizes mitochondrial re-energization and suggest that a circadian pattern of the TPN serves as a potentially beneficial strategy to reduce the risk of postischemic mitochondrial dysfunction in the liver.

Retinol and retinyl ester concentrations in rat tissues during total parenteral nutrition

We have previously observed that continuous total parenteral nutrition (TPN) that supplies retinyl palmitate induces a strong decrease of the circulating retinol, which is associated with an impaired hepatic production of retinol-binding protein. We have investigated the effect of 7 days of TPN on the retinol and retinyl ester concentrations in rat tissues, relative to the vitamin A status [ n = 30 for vitamin A-sufficient (A +) and n = 30 for deficient (A −)]. Rats were cannulated for intravenous feeding ( n = 12 for TPN-A +, n = 12 for TPN-A −) and were compared with their per os pair-fed counterparts ( n = 12 for O-A + and n = 12 for O-A −). Retinol and retinoic acid in serum and retinol and retinyl ester concentrations in liver, kidney, lung, heart, and testis were measured by high performance liquid chromatography. TPN induced a dramatic decrease in circulating retinol of A + rats, whereas retinoic acid concentration in serum was unchanged. When TPN was given to A − rats, retinol concentration in serum remained low. Lower retinol and retinyl ester concentrations were measured in the livers of TPN rats compared with orally pair-fed rats, no matter the initial vitamin A status ( P < 0.02 for A + and P < 0.01 for A −). By contrast, in extrahepatic tissues, retinol and retinyl ester concentrations were similar in TPN rats compared with orally pair-fed rats. Our results indicate that TPN induced a decrease of retinol in serum and retinyl esters in liver. However, TPN was able to maintain retinol and retinyl ester concentrations in extrahepatic tissues of vitamin A-sufficient rats and to restore retinol and retinyl ester concentrations in extrahepatic tissues of vitamin A-deficient rats, albeit a low circulating retinol.

Bolus intravenous infusion of amino acids or lipids does not stimulate gallbladder contraction in neonates on total parenteral nutrition

Background/Purpose: Stimulation of gallbladder contraction in patients receiving total parenteral nutrition (TPN) may be beneficial in preventing cholestatic jaundice associated with TPN. Bolus intravenous administration of either amino acids or fat promotes gallbladder contraction in normal adult volunteers after a period of starvation. This phenomenon has not been investigated in patients receiving continuous TPN. The aim of this study was to test the hypothesis that bolus intravenous infusion of amino acids or fat produces gallbladder contraction in neonates receiving TPN. Methods: Twenty-eight studies of gallbladder contraction were performed in 18 neonates receiving continuous TPN (median weight, 2.3 kg; range, 1.3 to 7.3; gestational age, 37 weeks; range, 28 to 40; age 6.5 days; range, 2 to 180). Different types of experiments were performed: (1) bolus intravenous infusion of amino acid or fat for 60 minutes at twice the normal infusion rate; (2) bolus intravenous infusion of amino acid or fat for 15 minutes at four times the normal infusion rate. Gallbladder volume was measured by real-time ultrasonography by a single investigator. Measurements were made before starting the bolus infusion and every 15 minutes for 1 hour. Results: The volume of the gallbladder before bolus intravenous infusion was not significantly different between experiments (median, 985; range, 603 to 1,802 mm 3). These volumes are consistent with an enlarged and atonic gallbladder as previously reported in infants receiving parenteral nutrition. In all experiments there was no significant decrease in gallbladder volume after bolus infusion of either amino acids or fat. Conclusions: Contrary to their effects in adults, bolus infusions of amino acids or fat did not induce gallbladder contraction in neonates on TPN. This may have been because of lack of starvation in the neonates and/or the effect of continuous glucose infusion.