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Induction of fecal cholesterol excretion is not effective for the treatment of hyperbilirubinemia in Gunn rats. Pediatr Res 2021; 89:510-517. [PMID: 32357361 DOI: 10.1038/s41390-020-0926-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/28/2020] [Accepted: 04/01/2020] [Indexed: 11/08/2022]
Abstract
BACKGROUND Unconjugated hyperbilirubinemia, a feature of neonatal jaundice or Crigler-Najjar syndrome, can lead to neurotoxicity and even death. We previously demonstrated that unconjugated bilirubin (UCB) can be eliminated via transintestinal excretion in Gunn rats, a model of unconjugated hyperbilirubinemia, and that this is stimulated by enhancing fecal fatty acid excretion. Since transintestinal excretion also occurs for cholesterol (TICE), we hypothesized that increasing fecal cholesterol excretion and/or TICE could also enhance fecal UCB disposal and subsequently lower plasma UCB concentrations. METHODS To determine whether increasing fecal cholesterol excretion could ameliorate unconjugated hyperbilirubinemia, we treated hyperbilirubinemic Gunn rats with ezetimibe (EZE), an intestinal cholesterol absorption inhibitor, and/or a liver X receptor (LXR) and farnesoid X receptor (FXR) agonist (T0901317 (T09) and obeticholic acid (OCA), respectively), known to stimulate TICE. RESULTS We found that EZE treatment alone or in combination with T09 or OCA increased fecal cholesterol disposal but did not lower plasma UCB levels. CONCLUSIONS These findings do not support a link between the regulation of transintestinal excretion of cholesterol and bilirubin. Furthermore, induction of fecal cholesterol excretion is not a potential therapy for unconjugated hyperbilirubinemia. IMPACT Increasing fecal cholesterol excretion is not effective to treat unconjugated hyperbilirubinemia. This is the first time a potential relation between transintestinal excretion of cholesterol and unconjugated bilirubin is investigated. Transintestinal excretion of cholesterol and unconjugated bilirubin do not seem to be quantitatively linked. Unlike intestinal fatty acids, cholesterol cannot "capture" unconjugated bilirubin to increase its excretion. These results add to our understanding of ways to improve and factors regulating unconjugated bilirubin disposal in hyperbilirubinemic conditions.
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Vodret S, Bortolussi G, Iaconcig A, Martinelli E, Tiribelli C, Muro AF. Attenuation of neuro-inflammation improves survival and neurodegeneration in a mouse model of severe neonatal hyperbilirubinemia. Brain Behav Immun 2018; 70:166-178. [PMID: 29458193 DOI: 10.1016/j.bbi.2018.02.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/06/2018] [Accepted: 02/15/2018] [Indexed: 01/21/2023] Open
Abstract
All pre-term newborns and a high proportion of term newborns develop neonatal jaundice. Neonatal jaundice is usually a benign condition and self-resolves within few days after birth. However, a combination of unfavorable complications may lead to acute hyperbilirubinemia. Excessive hyperbilirubinemia may be toxic for the developing nervous system leading to severe neurological damage and death by kernicterus. Survivors show irreversible neurological deficits such as motor, sensitive and cognitive abnormalities. Current therapies rely on the use of phototherapy and, in unresponsive cases, exchange transfusion, which is performed only in specialized centers. During bilirubin-induced neurotoxicity different molecular pathways are activated, ranging from oxidative stress to endoplasmic reticulum (ER) stress response and inflammation, but the contribution of each pathway in the development of the disease still requires further investigation. Thus, to increase our understanding of the pathophysiology of bilirubin neurotoxicity, encephalopathy and kernicterus, we pharmacologically modulated neurodegeneration and neuroinflammation in a lethal mouse model of neonatal hyperbilirubinemia. Treatment of mutant mice with minocycline, a second-generation tetracycline with anti-inflammatory and neuroprotective properties, resulted in a dose-dependent rescue of lethality, due to reduction of neurodegeneration and neuroinflammation, without affecting plasma bilirubin levels. In particular, rescued mice showed normal motor-coordination capabilities and behavior, as determined by the accelerating rotarod and open field tests, respectively. From the molecular point of view, rescued mice showed a dose-dependent reduction in apoptosis of cerebellar neurons and improvement of dendritic arborization of Purkinje cells. Moreover, we observed a decrease of bilirubin-induced M1 microglia activation at the sites of damage with a reduction in oxidative and ER stress markers in these cells. Collectively, these data indicate that neurodegeneration and neuro-inflammation are key factors of bilirubin-induced neonatal lethality and neuro-behavioral abnormalities. We propose that the application of pharmacological treatments having anti-inflammatory and neuroprotective effects, to be used in combination with the current treatments, may significantly improve the management of acute neonatal hyperbilirubinemia, protecting from bilirubin-induced neurological damage and death.
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Affiliation(s)
- Simone Vodret
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy
| | - Giulia Bortolussi
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy.
| | - Alessandra Iaconcig
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy
| | - Elena Martinelli
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy
| | - Claudio Tiribelli
- Centro Studi Fegato, Fondazione Italiana Fegato, AREA Science Park, Campus Basovizza, Trieste, Italy
| | - Andrés F Muro
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy.
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Park D, Kyung J, Kim D, Hwang SY, Choi EK, Kim YB. Anti-hypercholesterolemic and anti-atherosclerotic effects of polarized-light therapy in rabbits fed a high-cholesterol diet. Lab Anim Res 2012; 28:39-46. [PMID: 22474473 PMCID: PMC3315201 DOI: 10.5625/lar.2012.28.1.39] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 02/27/2012] [Accepted: 03/01/2012] [Indexed: 11/23/2022] Open
Abstract
The effects of polarized-light therapy (PLT) on high-cholesterol diet (HCD)-induced hypercholesterolemia and atherosclerosis were investigated in comparison with that of lovastatin in rabbits. Hypercholesterolemia was induced by feeding male New Zealand white rabbits with 1% cholesterol in diet for 2 weeks and maintained with 0.5% cholesterol for 6 weeks, followed by normal diet for 2 weeks for recovery. Lovastatin (0.002% in diet) or daily 5-min or 20-min PLT on the outside surface of ears was started 2 weeks after induction of hypercholesterolemia. Hypercholesterolemic rabbits exhibited great increases in serum cholesterol and low-density lipoproteins (LDL) levels, and finally severe atheromatous plaques formation covering 57.5% of the arterial walls. Lovastatin markedly reduced both the cholesterol and LDL, but the reducing effect (47.5%) on atheroma formation was relatively low. By comparison, 5-min PLT preferentially decreased LDL, rather than cholesterol, and thereby potentially reduced the atheroma area to 42.2%. Notably, 20-min PLT was superior to lovastatin in reducing both the cholesterol and LDL levels as well as the atheromatous plaque formation (26.4%). In contrast to the increases in blood alanine transaminase and aspartate transaminase following lovastatin treatment, PLT did not cause hepatotoxicity. In addition, PLT decreased platelets and hematocrit level. The results indicate that PLT attenuates atherosclerosis not only by lowering blood cholesterol and LDL levels, but also by improving blood flow without adverse effects. Therefore, it is suggested that PLT could be a safe alternative therapy for the improvement of hypercholesterolemia and atherosclerosis.
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Affiliation(s)
- Dongsun Park
- College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea
| | - Jangbeen Kyung
- College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea
| | - Dajeong Kim
- College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea
| | - Seock-Yeon Hwang
- Department of Biomedical Laboratory Science, Daejeon University, Daejeon, Korea
| | - Ehn-Kyoung Choi
- College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea
| | - Yun-Bae Kim
- College of Veterinary Medicine, Chungbuk National University, Cheongju, Korea
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Cuperus FJC, Iemhoff AA, Verkade HJ. Combined treatment strategies for unconjugated hyperbilirubinemia in Gunn rats. Pediatr Res 2011; 70:560-5. [PMID: 21857383 DOI: 10.1203/pdr.0b013e31823240bc] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We recently demonstrated that acceleration of the gastrointestinal transit by polyethylene glycol (PEG) treats unconjugated hyperbilirubinemia in jaundiced Gunn rats. It is unclear whether acceleration of gastrointestinal transit also (partly) underlies the therapeutic effects of established hypobilirubinemic treatments or whether PEG cotreatment might enhance these effects. We treated Gunn rats with phototherapy (17 μW/cm2/nm), orlistat (200 mg/kg chow), ursodeoxycholate (5 g/kg chow), or calcium phosphate (CaP) (20 g/kg chow) either as single treatment or in combination with PEG. Three weeks of phototherapy, orlistat, ursodeoxycholic acid, or CaP treatment decreased plasma unconjugated bilirubin (UCB) levels by 47, 27, 28, and 45%, respectively (each p < 0.001), without a significant impact on gastrointestinal transit time. PEG cotreatment accelerated the gastrointestinal transit in all treatment groups, which resulted in an additive hypobilirubinemic effect of -20% and -26% (final plasma UCB -67 and -53%, respectively) in phototherapy- and orlistat-treated animals. PEG cotreatment did not enhance the hypobilirubinemic effect of ursodeoxycholic acid or CaP. We conclude that phototherapy, orlistat, ursodoxycholic acid, and CaP do not exert their hypobilirubinemic effect via acceleration of the gastrointestinal transit. PEG cotreatment enhanced the hypobilirubinemic effects of phototherapy and of orlistat treatment. Current results support a clinical trial to evaluate PEG cotreatment during phototherapy.
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Affiliation(s)
- Frans J C Cuperus
- Department of Pediatrics, Beatrix Children's Hospital-University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands
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Bone mineral densities in individuals with Gilbert's syndrome: a cross-sectional, case-control pilot study. CANADIAN JOURNAL OF GASTROENTEROLOGY = JOURNAL CANADIEN DE GASTROENTEROLOGIE 2009; 23:431-6. [PMID: 19543574 DOI: 10.1155/2009/635126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Unconjugated bilirubin inhibits osteoblastic proliferative activity in vitro, raising the possibility that Gilbert's syndrome (GS) patients are at increased risk of osteoporosis. OBJECTIVES To compare bone mineral density (BMD), serum parathyroid hormone (PTH), C-telopeptide (CTX) and osteocalcin levels in GS subjects versus matched controls in a cross-sectional, case-control study. METHODS BMD determinations were obtained with central dual energy x-ray absorptiometry. Serum PTH, CTX and osteocalcin levels were measured by enzyme immunoassay. RESULTS A total of 17 GS and 30 control subjects were studied. Overall, there were no significant differences in BMD, PTH, CTX or osteocalcin levels between the two groups. However, when older (older than 40 years of age) and younger (40 years of age and younger) cohorts were considered separately, the older GS cohort had significantly decreased total hip BMD, T scores and Z scores, and femoral neck BMD, T scores and Z scores (P<0.005 for each parameter, respectively) compared with older control subjects. Serum osteocalcin levels were lower in the older versus younger GS cohort (P=0.006). An inverse correlation existed between all subjects' serum unconjugated bilirubin levels and total body BMD determinations (r=-0.42; P=0.04). On univariate analysis, the association between serum unconjugated bilirubin and total body BMD was not significant (P=0.066), nor was serum unconjugated bilirubin identified as a risk factor for low BMD when entered into multivariate analyses. CONCLUSIONS The results of the present pilot study warrant further research involving larger numbers of subjects and longitudinal measurements to determine whether GS is associated with decreased BMD, particularly in older GS subjects.
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Cuperus FJC, Hafkamp AM, Havinga R, Vitek L, Zelenka J, Tiribelli C, Ostrow JD, Verkade HJ. Effective treatment of unconjugated hyperbilirubinemia with oral bile salts in Gunn rats. Gastroenterology 2009; 136:673-82.e1. [PMID: 19027011 DOI: 10.1053/j.gastro.2008.10.082] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 10/01/2008] [Accepted: 10/30/2008] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS We tested the hypothesis that oral administration of bile salts, which are known to increase the biliary excretion of unconjugated bilirubin (UCB), decreases unconjugated hyperbilirubinemia in the Gunn rat model. METHODS Adult Gunn rats were fed a standard diet or the same diet supplemented with 0.5 weight % ursodeoxycholic acid (UDCA) or cholic acid (CA) for 1 or 6 weeks. UCB and urobilinoids, a family of intestinal UCB breakdown products, were determined in plasma, feces, or both. After 6 weeks of treatment, tracer 3H-UCB was administered intravenously to determine steady-state UCB kinetics over the next 60 hours. RESULTS One-week treatment with UDCA or CA decreased plasma UCB concentrations by 21% and 30%, respectively (each P < .01). During the first 4 days of treatment, both UDCA and CA increased the combined fecal excretion of UCB and urobilinoids (+52% and +32%, respectively; each P < .01). Prolongation of treatment to 6 weeks caused a persistent decrease in plasma UCB concentrations to approximately 40% below baseline (each bile salt P < .001). (3)H-UCB kinetic studies showed that UDCA and CA administration decreased UCB pool size (-33% and -32%, respectively; each P < .05) and increased UCB fractional turnover (+33% and +25%, respectively; each P < .05). CONCLUSIONS Dietary bile salt administration induces a large, persistent decrease in plasma UCB concentrations in Gunn rats. Both UDCA and CA enhance UCB turnover by increasing its fecal disposal. These results support the application of oral bile salt treatment in patients with unconjugated hyperbilirubinemia.
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Affiliation(s)
- Frans J C Cuperus
- Pediatric Gastroenterology, Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Fitzpatrick E, Mtegha M, Dhawan A. Crigler-Najjar syndrome: therapeutic options and consequences of mutations in the UGT1A1 complex. Expert Rev Endocrinol Metab 2008; 3:725-737. [PMID: 30764062 DOI: 10.1586/17446651.3.6.725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Crigler-Najjar syndrome (CN), a rare inherited disorder characterized by failure of bilirubin glucuronidation, can lead to severe disability and death from kernicterus. Gilbert syndrome is a more common, benign familial unconjugated hyperbilirubinemia. The underlying problem in both conditions is impaired bilirubin conjugation and elimination due to a mutation in uridine 5'-diphosphate glucuronyltransferase. The mainstay of current management of CN is phototherapy, followed by liver transplantation. Here, we review other therapies, including hepatocyte transplantation, that have been successfully used to lessen the phenotype, although long-term engraftment of cells remains elusive. Gene therapy holds hope for the future whereby the patient's hepatocytes are transduced with the wild-type gene. Outstanding issues include safety of the gene vector and establishing immunotolerance to both vector and the new protein. The significant advances in understanding the relevance of mutations in UGT not only in glucuronidation of bilirubin, but other drugs and substances, are also reviewed.
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Affiliation(s)
- Emer Fitzpatrick
- a Paediatric Liver Centre, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9PJ, UK
| | - Marumbo Mtegha
- a Paediatric Liver Centre, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9PJ, UK
| | - Anil Dhawan
- b Paediatric Liver Centre, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9PJ, UK.
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Buiter HD, Dijkstra SSP, Elferink RFMO, Bijster P, Woltil HA, Verkade HJ. Neonatal jaundice and stool production in breast- or formula-fed term infants. Eur J Pediatr 2008; 167:501-7. [PMID: 17619902 PMCID: PMC2668621 DOI: 10.1007/s00431-007-0533-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Accepted: 05/24/2007] [Indexed: 11/18/2022]
Abstract
It has remained unclear whether the amount of fecal fat excreted in the stool and stool production influences the severity of neonatal jaundice. We determined the relationship between stool production, fecal fat excretion and jaundice in healthy breast-fed (BF) or formula-fed (FF) (near-)term neonates. From postnatal day 1-4, we quantitatively collected stools from 27 FF and 33 BF infants in daily fractions. Stool production and fecal fat contents were related to unconjugated bilirubin (UCB) levels, as determined by transcutaneous bilirubinometry (TcB). Bilirubin concentrations and stool production did not differ between FF and BF neonates during the study period. Neonatal bilirubin levels were not inversely correlated with stool production. FF and BF infants had similar fecal fat excretion rates. The stool production of FF infants was profoundly lower in the present study than in a 1985 study by De Carvalho et al. [J Pediatr (1985) 107:786-790]. We conclude that increased jaundice during the first postnatal days in healthy term neonates can no longer be attributed to breast-feeding and speculate that improved absorbability of formulas since 1985 has contributed to similar fat excretion and stool production in FF and BF neonates in 2007.
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Affiliation(s)
- Hannah D Buiter
- University Medical Center Groningen, Groningen, The Netherlands
| | | | | | | | | | - Henkjan J Verkade
- University Medical Center Groningen, Groningen, The Netherlands
- Pediatric Gastroenterology/Hepatology, Department Pediatrics, University Medical Center Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
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Hafkamp AM, Nelisse-Haak R, Sinaasappel M, Oude Elferink RPJ, Verkade HJ. Orlistat treatment of unconjugated hyperbilirubinemia in Crigler-Najjar disease: a randomized controlled trial. Pediatr Res 2007; 62:725-30. [PMID: 17957158 DOI: 10.1203/pdr.0b013e3181598cc5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Unconjugated hyperbilirubinemia in Crigler-Najjar (CN) disease is conventionally treated with phototherapy and phenobarbital. Orlistat treatment increases fecal fat excretion and decreases plasma unconjugated bilirubin (UCB) concentrations in Gunn rats, the animal model for CN disease. We determined in CN patients the effects of orlistat treatment on plasma UCB concentrations, and on fecal excretion of fat and UCB. A randomized, placebo-controlled, double-blind, cross-over trial was conducted in 16 patients, simultaneous with their regular treatment (phototherapy, n = 11, and/or phenobarbital, n = 6). Patients received orlistat or placebo, each for 4-6 wk. Compared with placebo, orlistat increased fecal fat excretion (+333%) and fecal UCB excretion (+43%). Orlistat treatment significantly decreased plasma UCB concentration (-9%). In 7 of 16 patients, the decrease in plasma UCB levels was clinically relevant (>10%, mean 21%). In patients with a clinically relevant response, plasma UCB concentrations during orlistat were strongly, negatively correlated with fecal fat excretion (r = -0.93). Clinically relevant response to orlistat treatment was not correlated with age, sex, CN type, BMI, or co-treatment with phototherapy or phenobarbital, but appeared correlated with a relatively lower dietary fat intake. In conclusion, orlistat treatment decreases plasma UCB concentrations, particularly in a subgroup of CN patients. Dietary fat intake may determine the responsiveness to orlistat treatment.
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Affiliation(s)
- Anja M Hafkamp
- Department of Pediatrics, Pediatric Gastroenterology, Center for Liver, Digestive and Metabolic Diseases, University of Groningen, 9700 RB, Groningen, The Netherlands
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Gooijert KER, Havinga R, Oosterloo-Duinkerken AR, Venekamp-Hoolsema EEA, Kuipers F, Verkade HJ. Stimulation of fecal fat excretion and the disposal of protoporphyrin in a murine model for erythropoietic protoporphyria. Am J Physiol Gastrointest Liver Physiol 2007; 293:G510-6. [PMID: 17600043 DOI: 10.1152/ajpgi.00102.2007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Erythropoietic protoporphyria (EPP) is characterized by toxic accumulation of the hydrophobic compound protoporphyrin (PP). Ferrochelatase-deficient (fch/fch) mice are an animal model for human EPP. Recently, we have demonstrated that the accumulation of another hydrophobic compound, unconjugated bilirubin, could effectively be treated by stimulation of fecal fat excretion. We investigated whether stimulation of fecal fat excretion enhanced the disposal of PP in fch/fch mice. Fch/fch mice were fed for 8 wk with a high-fat diet (16 wt% fat; control) or with the high-fat diet mixed with either a nonabsorbable fat (sucrose polyester) or the intestinal lipase inhibitor orlistat. The effects of the treatments on fecal excretion of fat and PP and on hepatic PP concentrations were compared with control diets. Fecal fat excretion in fch/fch mice on a high-fat diet was higher than in mice on a low-fat diet (+149%, P < 0.05). Sucrose polyesters and orlistat increased fecal fat excretion even more, up to sixfold of control values. However, none of the different treatments affected fecal PP excretion or hepatic PP concentration. Treatment of fch/fch mice with a high-fat diet, a nonabsorbable fat diet, or with orlistat increased the fecal excretion of fat but did not increase fecal PP excretion or decrease hepatic PP concentration. The present data indicate that accumulation of PP is not amenable to stimulation of fecal fat excretion.
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Affiliation(s)
- Karin E R Gooijert
- Pediatric Gastroenterology, Department of Pediatrics, Groningen University Institute for Drug Exploration, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands
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Hafkamp AM, Havinga R, Ostrow JD, Tiribelli C, Pascolo L, Sinaasappel M, Verkade HJ. Novel kinetic insights into treatment of unconjugated hyperbilirubinemia: phototherapy and orlistat treatment in Gunn rats. Pediatr Res 2006; 59:506-12. [PMID: 16549520 DOI: 10.1203/01.pdr.0000203180.79636.98] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Treatment with phototherapy or with the lipase inhibitor orlistat decreases plasma unconjugated bilirubin (UCB) concentrations in hyperbilirubinemic Gunn rats. We investigated the mechanism(s) underlying the effects of orlistat, phototherapy, and combined treatment, using steady-state 3H-UCB kinetics. After three weeks of treatment with orlistat (200 mg/kg chow), phototherapy (19 microW/cm2/nm) or combined treatment, tracer 3H-UCB was administered IV to treated and untreated (control) Gunn rats. Plasma samples and feces were collected every 12h for 60h, and bile for 30 min at 60h. The following results were obtained: 1) each treatment decreased plasma bilirubin levels compared with controls: orlistat- 19%, phototherapy-32%, combined treatment-53%; 2) plasma bilirubin concentrations were strongly, negatively correlated with fractional bilirubin turnover; 3) orlistat treatment induced net transmucosal excretion of UCB into the intestinal lumen, whereas phototherapy increased biliary UCB excretion rate; 4) all treatments profoundly increased the enterohepatic circulation of UCB derivatives, indicating enhanced metabolism by intestinal bacteria. In conclusion, orlistat and phototherapy lower plasma bilirubin concentrations in Gunn rats by increasing (net) intestinal influx of UCB, either by transmucosal excretion (orlistat), or increased biliary secretion (phototherapy). The mechanism of phototherapy and orlistat treatment involves increasing the availability of UCB in the intestinal lumen for fecal excretion and for metabolism by intestinal bacteria.
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Affiliation(s)
- Anja M Hafkamp
- Pediatric Gastroenterology, Center for Liver, Digestive and Metabolic Disorders, University Medical Center Groningen, The Netherlands
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Garcia SB, Barros LTDC, Turatti A, Martinello F, Modiano P, Ribeiro-Silva A, Vespúcio MVDO, Uyemura SA. The anti-obesity agent Orlistat is associated to increase in colonic preneoplastic markers in rats treated with a chemical carcinogen. Cancer Lett 2005; 240:221-4. [PMID: 16377080 DOI: 10.1016/j.canlet.2005.09.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Accepted: 09/20/2005] [Indexed: 11/15/2022]
Abstract
Orlistat is an anti-obesity agent that increases the fecal fat excretion, which promotes colon carcinogenesis. Therefore, the present study was designed to verify the effects of Orlistat on the formation of rat colonic aberrant crypt foci (ACF) and cell proliferation evaluated by the PCNA method. Male Wistar rats received either a standard diet or a high fat diet (HFD), supplemented or not with Orlistat (200mg/kg chow) and two doses of the carcinogen dimethyl-hydrazine (25mg/Kg). After 30 days, Orlistat was associated to a significant increase in the number of colonic ACFs and cell proliferation in DMH-treated animals, independently of the HFD.
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Affiliation(s)
- Sérgio Britto Garcia
- Department of Pathology, Ribeirão Preto Medical School, University of São Paulo, USP, Avenida Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brazil.
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