| 1. |
- Budrikis, A, et al.
(författare)
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Function of adult pig hearts after 2 and 12 hours of cold cardioplegic preservation
- 1998
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 66:1, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Most cardioplegic solutions have been developed using the classic Langendorf heart perfusion model, which only allows a short experimental follow-up. Our aim was to investigate hearts after prolonged storage by using a physiologic model including prolonged perfusion with normal, fresh blood. METHODS: Sixteen hearts from 60-kg pigs were preserved with dextran-enriched (dextran-40, 35 g/L) St. Thomas' solution for 2 or 12 hours after which they were continuously reperfused for 12 hours with normal blood, supplied by a support pig. A flexible balloon, fixed to an artificial valve apparatus connected to a circuit system, was inserted in the left ventricle for obtaining measurements of hemodynamic performance. RESULTS: During the first 3 to 4 hours of reperfusion there was no significant difference in left ventricular developed pressure, cardiac output, minute work output, or oxygen consumption between the two groups. After this time left ventricular developed pressure (p < 0.001), cardiac output (p < 0.01), minute work output (p < 0.01), and oxygen consumption were significantly lower in the 12-hour group. Coronary flow was higher (p < 0.01) and coronary vascular resistance lower (p < 0.01) during the first 5 to 6 hours of reperfusion in the 12-hour group. After 12 hours of reperfusion coronary vascular resistance was significantly higher (p < 0.01) in the 12-hour group. CONCLUSIONS: High-degree and long-lasting coronary hyperemia at the beginning of reperfusion can be a sign of unsatisfactory preservation of the heart. This investigation shows the importance of reperfusion with normal blood and a long follow-up period after postischemic reperfusion when studying the effect of cardioplegic solutions.
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| 2. |
- Ingemansson, Richard, et al.
(författare)
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Addition of calcium to Euro-Collins solution is essential for 24-hour preservation of the vasculature
- 1997
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 63:2, s. 408-413
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Genuine Euro-Collins solution is calcium free. The aim of this study was to investigate whether the addition of calcium would improve its capacity to preserve the vasculature. METHODS: The infrarenal aorta of Sprague-Dawley rats was investigated in organ baths: as fresh controls, after 24 hours of cold (4 degrees C) storage in Euro-Collins solution, or in Euro-Collins solution with the addition of calcium in amounts ranging from 0.05 to 1.5 mmol/L. The thromboxane analogue U-46619 was used to investigate contractility. Endothelium-dependent relaxation was tested by cumulative addition of acetylcholine. Papaverine was used to elicit endothelium-independent relaxation. Investigation by transmission electron microscopy was also performed. RESULTS: Storage of rat aorta for 24 hours in genuine Euro-Collins solution almost abolished smooth muscle function, and severe edema was found in the endothelial cells. However, if calcium was added, the rat aorta could be stored for 24 hours without affecting smooth muscle function, and endothelium-dependent relaxation was only slightly reduced. Furthermore, only slight edema could be demonstrated in the endothelial cells. CONCLUSIONS: If calcium is added to Euro-Collins solution in amounts ranging from 0.4 to 1.5 mmol/L, it allows good preservation of rat aorta for 24 hours. Without calcium, this solution destroys both the function and morphology of the vessels.
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| 3. |
- Ingemansson, Richard, et al.
(författare)
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Effect of flush-perfusion on vascular endothelial and smooth muscle function
- 1997
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 64:4, s. 1075-1081
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to investigate how much perfusion pressure an artery can tolerate without significant loss of endothelium-dependent relaxation (EDR) and vascular contractility. METHODS: The abdominal aortas of 396 Sprague-Dawley rats were used. One hundred twenty aortas were flush-perfused for 1 or 5 minutes with cold St. Thomas' Hospital cardioplegic (STHC) solution or with the same solution but modified by the addition of 3.5% dextran 40. Three perfusion pressures were tested: 50, 100, and 150 mm Hg. Two hundred eighty vessels were subjected to pressures of 50, 150, or 300 mm Hg using saline or STHC solution at 22 degrees C or STHC solution at 4 degrees C, for 10 or 60 seconds. The vessels were investigated in organ baths. Contractility was tested with the thromboxane analogue U-46619, acetylcholine was used to investigate EDR, and papaverine to elicit endothelium-independent relaxation. RESULTS: Flush-perfusion with cold STHC solution for 5 minutes at a perfusion pressure of 50 or 100 mm Hg affected neither contractility nor EDR. Vessels exposed to a flush-perfusion pressure of 150 mm Hg for 1 or 5 minutes lost 39% (p < 0.001) and 53% (p < 0.001) of their contractility, respectively. Flush-perfusion at 150 mm Hg for 1 minute did not affect EDR, whereas 5 minutes' perfusion caused a reduction of 7% (p < 0.05). A repetition of these experiments using STHC solution with 3.5% dextran 40 added gave no significantly different results. The impairment in contractility and EDR seen after perfusion at 150 mm Hg for 5 minutes disappeared after transplantation and reperfusion for 7 days. The vessels could be distended with saline or STHC solution at a pressure of 150 mm Hg without affecting contractility at 22 degrees C. At 4 degrees C, however, this pressure was harmful to contractility. Distention at a pressure of 300 mm Hg almost abolished contractility and 7 days after transplantation there had not yet been any recovery of contractility, but 30 days after transplantation the grafts had regained their normal contractility. CONCLUSIONS: Cold STHC solution, with or without dextran 40, can be used with a perfusion pressure of 100 but not 150 mm Hg without impairing EDR or vascular smooth muscle function.
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| 4. |
- Ingemansson, Richard, et al.
(författare)
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Effect of temperature in long-term preservation of vascular endothelial and smooth muscle function
- 1996
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Ingår i: Annals of Thoracic Surgery. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 61:5, s. 1413-1417
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. In clinical transplantation the donor organ is perfused with a cold preservation solution to obtain quick core cooling and a suitable environment for the tissue cells. Without good preservation of the vasculature, progressive deterioration of the blood flow during reperfusion may ultimately lead to the no-reflow phenomenon, even though the function of the other cells in the organ may be adequately preserved. The aim of this study was to find the optimal storage temperature for preservation of the vasculature. METHODS. The infrarenal aorta of 126 Sprague-Dawley rats were studied in organ baths: as fresh controls, after 36 hours of storage at 0.5 degrees C, 4 degrees C, 8.5 degrees C, and 22 degrees C in University of Wisconsin solution, and after 36-hour storage followed by transplantation and a lapse of 2 hours, 24 hours, and 7 days. The thromboxane analogue U-46619 was used to test contractility. Acetylcholine was used to elicit endothelium-dependent relaxation (EDR), and papaverine to elicit endothelium-independent relaxation. RESULTS. Storing the vessels at 0.5 degree C proved best regarding preservation of contractility, with a nonsignificant decrease, whereas storage at 4 degrees C and 8.5 degrees C resulted in a significant decrease after 36 hours. The contractility did not recover within 24 hours of in vivo reperfusion, but full recovery was seen after 7 days. Regardless of the preservation temperature used, a significant impairment in EDR was seen after 36 hours of storage. Two hours after transplantation, vessels stored at 4 degrees C and 8.5 degrees C showed no significant impairment in EDR, whereas those stored at 0.5 degrees C demonstrated a significant loss of EDR. After 24 hours and after 7 days, EDR was normal in all groups. CONCLUSIONS. Endothelium-dependent relaxing factor function is best preserved at 4 degrees C and 8.5 degrees C, whereas preservation of vascular smooth muscle function is best preserved at 0.5 degrees C.
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| 5. |
- Ingemansson, Richard, et al.
(författare)
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Importance of calcium in long-term preservation of the vasculature
- 1996
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 61:4, s. 1158-1162
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim was to investigate the effect of calcium in organ preservation solutions with respect to 36-hour preservation of vascular smooth muscle function and endothelium-dependent relaxation. METHODS: The infrarenal aortas of 60 Sprague-Dawley rats were studied in organ baths as fresh controls and after 36 hours of cold (4 degrees C) storage in different preservation solutions with and without calcium. The thromboxane A2 analogue U-46619 was used to study contractility. Endothelium-dependent relaxation was tested by the cumulative addition of acetylcholine. Papaverine hydrochloride was used to elicit endothelium-independent relaxation. RESULTS: Krebs solution was the only solution able to fully preserve contractility. Krebs solution without calcium gave poor preservation. After the addition of 1.5 mmol/L of calcium to University of Wisconsin solution and to Perfadex, both these solutions became fully able to preserve contractility. None of the solutions (with or without calcium) were fully able to preserve endothelium-dependent relaxation, although University of Wisconsin solution gave good preservation and Perfadex, fair preservation. Euro-Collins solution and K+ (124 mmol/L)-enriched Krebs solution were not able to preserve smooth muscle function or endothelium-dependent relaxation. CONCLUSIONS: Calcium is essential for long-term preservation of vascular smooth muscle function but not for long-term preservation of endothelium-dependent relaxation.
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| 6. |
- Ingemansson, Richard, et al.
(författare)
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Long-term preservation of vascular endothelium and smooth muscle
- 1995
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Ingår i: Annals of Thoracic Surgery. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 59:5, s. 1177-1181
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Tidskriftsartikel (refereegranskat)abstract
- This study was performed in organ baths on 400 ring segments of infrarenal aorta taken from 40 Sprague-Dawley rats that had been randomized into five groups. Contractility was tested with the thromboxane analogue U-46619. Acetylcholine was used to elicit endothelium-dependent relaxing factor (EDRF). The results obtained from vessels preserved at 4 degrees C for 6, 12, 24, and 36 hours were compared with those from autologous vessels studied immediately after harvesting. Vessels preserved in Euro-Collins solution showed a 46% (p < 0.01) decrease in contractility after 12 hours of storage; after 24 hours only weak contractions could be elicited, and after 36 hours they had lost their ability to contract. The EDRF function was slightly reduced after 12 hours and could not be investigated after 24 and 36 hours. With the University of Wisconsin solution (UW) and the low-potassium-dextran-glucose solution Perfadex no decrease in contractility was seen in the first 24 hours, but at 36 hours the vessels preserved in UW had lost 40% (p < 0.01) and those preserved in Perfadex 30% (p < 0.05) of their contractility. The EDRF function was significantly reduced by about 15% after 6, 12, and 24 hours in both the UW and the Perfadex groups. At 36 hours, vessels stored in Perfadex had lost 41% (p < 0.001) and those stored in UW 17% (p < 0.01) of their EDRF function.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 7. |
- Ingemansson, Richard, et al.
(författare)
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Perfadex is superior to Euro-Collins solution regarding 24-hour preservation of vascular function
- 1995
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 60:5, s. 1210-1214
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. The aim of this study was to compare Perfadex with Euro-Collins solution regarding 24-hour preservation of endothelium-dependent relaxation and vascular smooth muscle function. METHODS. The infrarenal aorta of 72 isogenic rats was studied in organ baths as fresh controls, after 24 hours of cold (4 degrees C) storage, and after 24-hour storage followed by transplantation and examination after 7 or 30 days. The thromboxane A2 analogue U-46619 was used to test contractility. Acetylcholine chloride was used to elicit endothelium-dependent relaxation and papaverine hydrochloride, to elicit endothelium-independent relaxation. RESULTS. With both solutions, all grafts were patent after 7 and 30 days. Vessels preserved in Euro-Collins solution for 24 hours lost 95% (p < 0.001) of their contractility compared with fresh controls; 7 days after transplantation, they had regained 40% of initial contractility, and after 30 days, there was no significant decrease in contractility. Vessels preserved in Perfadex manifested no significant decrease in contractility at any time. Endothelium-dependent relaxation could not be evaluated in vessels stored for 24 hours in Euro-Collins solution because they had lost almost all contractility; 7 days after transplantation, endothelium-dependent relaxation was reduced by 65% (p < 0.001), but at 30 days after transplantation, there was no significant decrease in endothelium-dependent relaxation. Vessels preserved in Perfadex for 24 hours lost 17% (p < 0.05) of endothelium-dependent relaxation, but 7 and 30 days after transplantation, there was no significant decrease in endothelium-dependent relaxation. CONCLUSIONS. Perfadex, but not Euro-Collins solution, has the capacity to preserve vascular function after 24 hours of storage followed by in vivo reperfusion.
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| 8. |
- Kimblad, Per Ola, et al.
(författare)
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Endothelium-dependent relaxation in pulmonary arteries after lung preservation and transplantation
- 1993
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 56:6, s. 1329-1333
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary hypertension is frequently seen after lung transplantation. To study how the release of the endothelium-dependent relaxing factor is affected by lung preservation and transplantation, porcine pulmonary arteries were investigated in organ baths. The arteries (1 mm in diameter) were taken from fresh nonperfused lungs (group I), lungs immediately after flush-perfusion with a low-potassium-dextran solution (group II), non-perfused lungs stored for 12 hours in low-potassium-dextran solution (group III), flush-perfused lungs stored for 12 hours in low-potassium-dextran solution (group IV), and group IV lungs after left lung transplantation and right pneumonectomy followed by 24 hours of reperfusion (group V). Stable contractions were induced with the thromboxane A2 analogue U-46619. Acetylcholine was used to stimulate the release of endothelium-dependent relaxing factor. In vessel segments where the endothelium had been removed, acetylcholine elicited no response. In segments with intact endothelium, acetylcholine induced concentration-dependent relaxation; the maximum relaxation obtained was 91% +/- 3% (I), 86% +/- 3% (II), 85% +/- 3% (III), 69% +/- 5% (IV), and 69% +/- 9% (V). Relaxation was significantly reduced in groups IV (p < 0.01) and V (p < 0.05) as compared with group I. Stable moderate pulmonary hypertension was present in all the transplanted lungs throughout the 24-hour observation period. It is concluded that the endothelium-mediated relaxation is significantly reduced after flush perfusion combined with 12 hours of storage in low-potassium-dextran solution. Lung transplantation, followed by 24 hours of reperfusion did not further impair the endothelium-dependent relaxation.
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| 9. |
- Kimblad, Per Ola, et al.
(författare)
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High potassium contents in organ preservation solutions cause strong pulmonary vasocontraction
- 1991
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 52:3, s. 523-528
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Tidskriftsartikel (refereegranskat)abstract
- Euro-Collins (ECS) and UCLA-formula organ preservation solutions induced strong vasocontraction in porcine pulmonary arteries when studied in organ baths at temperatures of 37 degrees C and 30 degrees C. At 20 degrees C ECS induced a 30% contraction, but at 6 degrees C no contraction (n = 5) or a weak contraction (n = 1) was elicited. Neither prostaglandin E1 nor nifedipine caused any significant reduction of the vasocontraction elicited by ECS and UCLA. Krebs solution, enriched with potassium in amounts corresponding to those in ECS (115 mmol/L) or UCLA (30 mmol/L), induced vasocontraction comparing well with those induced by ECS or UCLA, indicating that it is the high potassium content that causes the vasocontraction. In a second experiment lung segments were stored at 4 degrees C for 9 hours in ECS, UCLA, or Krebs solution. Pulmonary arterial segments were then studied in organ baths at 37 degrees C. The choice of preservation solution did not significantly affect the contractile properties of potassium, noradrenaline, or the thromboxane mimic U-46619. To conclude, high potassium contents in organ preservation solutions induce strong pulmonary vasocontraction in lung temperatures greater than 20 degrees C but not in temperatures less than 10 degrees C. These vasocontractions are not significantly reduced by prostaglandin E1 or nifedipine. We suggest that the initial preservation solution used to cool down the lungs should contain 4 mmol/L or no potassium. When the lung temperature is less than 10 degrees C, a second perfusion might be done, and then a high potassium content (if thought to be essential) will not cause vasocontraction.
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| 10. |
- Kimblad, Per Ola, et al.
(författare)
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Pulmonary vascular resistance related to endothelial function after lung transplantation
- 1994
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 58:2, s. 416-420
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Tidskriftsartikel (refereegranskat)abstract
- In 8 donor pigs, flush perfusion was performed with a low-potassium-dextran solution. Ring segments were taken from a small intralobar pulmonary artery in the right lung immediately after perfusion and after 24 hours of cold storage for studies in organ baths. Stable vasoconstriction was induced with the thromboxane mimic U-46619, and acetylcholine was used to induce endothelium-dependent relaxation. The maximum relaxation was significantly reduced after flush perfusion compared with fresh nonperfused controls, and a significant additional reduction was seen after the 24-hour storage period. The left donor lung was transplanted into a recipient after 24 hours of cold storage. Contralateral pneumonectomy was then performed, making the recipient entirely dependent on the transplanted lung for survival. All 8 pigs were in good condition throughout the 24-hour observation period, with arterial oxygen tension of around 165 mm Hg (range, 80 to 275 mm Hg; inspired oxygen fraction, 0.5) and pulmonary vascular resistance of around 450 dyne.s.cm-5 (range, 260 to 730 dyne.s.cm-5). The maximum endothelium-dependent relaxation for each donor was checked for correlation to pulmonary vascular resistance and to systolic, mean, and diastolic pulmonary artery pressures as recorded at 4-hour intervals. Regression analyses showed arterial oxygen tension to be unrelated to pulmonary vascular resistance and endothelial dysfunction to be unrelated to pulmonary artery pressure but to correlate to pulmonary vascular resistance, this correlation being significant after reperfusion for 16 hours (p < 0.05) and highly significant after 24 hours (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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