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Preservation solutions for hepatic transplantation : Evaluation by 31P NMR in the hypothermic rat liver
PC-19
P.RES~VATION SOLUTIONS FOR HEPATIC TRANSPLANTATION : EVALUATION BY 31p N3~ IN THE HYPOTHERMIC RAT LIVER B.BJ Fuller I A Busza*~ E Proctor*~ D Gadian*~ & K E F Hobbs Academic Department of Surgery, Royal Free Hospital & Medical School, London NW3 2QG & Physics *, The Royal College of Surgeons, London WC2A 3PN, U K Vasc~ar flush with a cold synthetic solution is used for organ storage during transplantation. ~ P NMR studies were performed on isolated rat livers ( n= 4 per group ) at 5-8 C after portal perfusion with 200 ml of 3 pre-chilled solutions : a) Ringer v s solution; b) MarshallV s Citrate solution and c) Collins v solution. Spectra were collected at 0.25, 0.5, I, 2, 4, 8 & 24 hr post-flushing. For all 3 solutions the results showed : I) ATP was visible immediately and declined to become invisible at 1-2 hr; 2) ADP stayed initially constant and then became uaqdetectable at 2-4 hr; 3) AMP and sugar phosphates increased over 8 hr and then changed little; 4) tissue inorganic phosphate increased progressively over 24 hr; 5) pH decreased in a biphasic manner with a sharp initial fall over 2 hr and a slow further decline t o N p H 6.5 at 24 hr. The data show that the 3 solutions were only partly effective in preventing catabolism of adenine nucleotides at hypothermia; surprisingly, Collins! and Marshall Is solution provided no better buffering capacity against H i- accumulation than Ringer! s. These preliminary N~R studies need to be correlated with other f~ctional tests, but they indicate that the technique may play a major future role in the development of better liver preservation protocols.
PC-20
CAN THE URINARY EXCRETION OF 6~HYDROXYCORTISOL ALLOW FOR THE PREDICTION OF THE OPTIMAL POSOLOGYOF CYCLOSPORIN ~ IN TRANSPLANT RECIPIENTS. * * ~ , J.M.Rouillon , P.Bories , H.Michel , C.Ged**, P.Naurel , Service des Maladies de l'~p~l~areil D i g e s t i f , CHR St-Eloi, 34059 Montpellier; INSERMU-75 Necker, 75730 Paris Cedex 15; INSERH U-128, BP 5051, 34033 Montpe]lier Cedex.
In the transplant r e c i p i e n t , adapted posology of cyclosporin A (CSA) requires a d a i l y blood level control. CSA is primarily metaboiised in the l i v e r by a form of microsomal cytochrom P450, PhSO H3C. The hepatic level of this cytochrem cannot be predicted since genetically controlled and influenced by a lot of xenobiotic inducers or inhibitors. P450 H3C also appears to be involved in the 6~ hydroxylation of steroTds and specially in the production of 6~ hydroxycortisol (6 ~ OHC). The aim of this work was : I) to compare the hepatic concentration of P450 H3C and the urinary excretion of 6& OHC, before and after induction of the cytochrome; 2) to work out a non invasive method allowing for the estimation of the hepatic level of P450 H3C, in order to evaluate the metabolism of CSA and accordingly adapt its posology. Patients and methods : 12 adult patients of both sexes, hospitaIised for digestive neoplasia, were selected. A l i v e r needle biopsy had been obtained during the preevaluation test of their illness, before any medication; a second l i v e r biopsy was obtained from surgery during the tumor excision, after a five day treatment with rifampicin (10 mg/Kg/day), a known inducer of P450 H3C. The l i v e r specimens were histologically normal. Cytochrome P450 M3C was determined by immunoelectrophoresis (western blot) on the microsomal fraction prepared from the biopsies. Twenty four hours urine samples were collected the day before each biopsy and the level of 6~OHC was determined by HPLC. Results : in all patients, rifampicin treatment produces a significant average increase of both P450 H3C and 6~ OHC levels, 5.4 and 4.8 fold, respectively; the average basic values are 0.3 (arbitrary unit) and 523 ug/24 h, respectively. In conclusion, we suggest that the urinary level of 6~ONC could be a good indicator of the hepatic level of P4SO H3C and could therefore allow for the prediction of optimal poselogy of CSA in the transplant recipient.
$88
P.RES~VATION SOLUTIONS FOR HEPATIC TRANSPLANTATION : EVALUATION BY 31p N3~ IN THE HYPOTHERMIC RAT LIVER B.BJ Fuller I A Busza*~ E Proctor*~ D Gadian*~ & K E F Hobbs Academic Department of Surgery, Royal Free Hospital & Medical School, London NW3 2QG & Physics *, The Royal College of Surgeons, London WC2A 3PN, U K Vasc~ar flush with a cold synthetic solution is used for organ storage during transplantation. ~ P NMR studies were performed on isolated rat livers ( n= 4 per group ) at 5-8 C after portal perfusion with 200 ml of 3 pre-chilled solutions : a) Ringer v s solution; b) MarshallV s Citrate solution and c) Collins v solution. Spectra were collected at 0.25, 0.5, I, 2, 4, 8 & 24 hr post-flushing. For all 3 solutions the results showed : I) ATP was visible immediately and declined to become invisible at 1-2 hr; 2) ADP stayed initially constant and then became uaqdetectable at 2-4 hr; 3) AMP and sugar phosphates increased over 8 hr and then changed little; 4) tissue inorganic phosphate increased progressively over 24 hr; 5) pH decreased in a biphasic manner with a sharp initial fall over 2 hr and a slow further decline t o N p H 6.5 at 24 hr. The data show that the 3 solutions were only partly effective in preventing catabolism of adenine nucleotides at hypothermia; surprisingly, Collins! and Marshall Is solution provided no better buffering capacity against H i- accumulation than Ringer! s. These preliminary N~R studies need to be correlated with other f~ctional tests, but they indicate that the technique may play a major future role in the development of better liver preservation protocols.
PC-20
CAN THE URINARY EXCRETION OF 6~HYDROXYCORTISOL ALLOW FOR THE PREDICTION OF THE OPTIMAL POSOLOGYOF CYCLOSPORIN ~ IN TRANSPLANT RECIPIENTS. * * ~ , J.M.Rouillon , P.Bories , H.Michel , C.Ged**, P.Naurel , Service des Maladies de l'~p~l~areil D i g e s t i f , CHR St-Eloi, 34059 Montpellier; INSERMU-75 Necker, 75730 Paris Cedex 15; INSERH U-128, BP 5051, 34033 Montpe]lier Cedex.
In the transplant r e c i p i e n t , adapted posology of cyclosporin A (CSA) requires a d a i l y blood level control. CSA is primarily metaboiised in the l i v e r by a form of microsomal cytochrom P450, PhSO H3C. The hepatic level of this cytochrem cannot be predicted since genetically controlled and influenced by a lot of xenobiotic inducers or inhibitors. P450 H3C also appears to be involved in the 6~ hydroxylation of steroTds and specially in the production of 6~ hydroxycortisol (6 ~ OHC). The aim of this work was : I) to compare the hepatic concentration of P450 H3C and the urinary excretion of 6& OHC, before and after induction of the cytochrome; 2) to work out a non invasive method allowing for the estimation of the hepatic level of P450 H3C, in order to evaluate the metabolism of CSA and accordingly adapt its posology. Patients and methods : 12 adult patients of both sexes, hospitaIised for digestive neoplasia, were selected. A l i v e r needle biopsy had been obtained during the preevaluation test of their illness, before any medication; a second l i v e r biopsy was obtained from surgery during the tumor excision, after a five day treatment with rifampicin (10 mg/Kg/day), a known inducer of P450 H3C. The l i v e r specimens were histologically normal. Cytochrome P450 M3C was determined by immunoelectrophoresis (western blot) on the microsomal fraction prepared from the biopsies. Twenty four hours urine samples were collected the day before each biopsy and the level of 6~OHC was determined by HPLC. Results : in all patients, rifampicin treatment produces a significant average increase of both P450 H3C and 6~ OHC levels, 5.4 and 4.8 fold, respectively; the average basic values are 0.3 (arbitrary unit) and 523 ug/24 h, respectively. In conclusion, we suggest that the urinary level of 6~ONC could be a good indicator of the hepatic level of P4SO H3C and could therefore allow for the prediction of optimal poselogy of CSA in the transplant recipient.
$88