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Effects of freezing, fixation and dehydration on surface roughness properties of porcine left anterior descending coronary arteries. Micron 2017; 101:78-86. [PMID: 28662414 DOI: 10.1016/j.micron.2017.06.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/15/2017] [Accepted: 06/19/2017] [Indexed: 12/23/2022]
Abstract
BACKGROUND To allow measurements of surface roughness to be made of coronary arteries using various imaging techniques, chemical processing, such as fixation and dehydration, is commonly used. Standard protocols suggest storing fresh biological tissue at -40°C. The aim of this study was to quantify the changes caused by freezing and chemical processing to the surface roughness measurements of coronary arteries, and to determine whether correction factors are needed for surface roughness measurements of coronary arteries following chemical processes typically used before imaging these arteries. METHODS Porcine left anterior descending coronary arteries were dissected ex vivo. Surface roughness was then calculated following three-dimensional reconstruction of surface images obtained using an optical microscope. Surface roughness was measured before and after a freeze cycle to assess changes during freezing, after chemical fixation, and again after dehydration, to determine changes during these steps of chemical processing. RESULTS No significant difference was caused due to the freeze cycle (p>0.05). There was no significant difference in the longitudinally measured surface roughness (RaL=0.99±0.39μm; p>0.05) of coronary arteries following fixation and dehydration either. However, the circumferentially measured surface roughness increased significantly following a combined method of processing (RaC=1.36±0.40, compared 1.98±0.27μm, respectively; p<0.05). A correction factor can compensate for the change RaCβ=RaC1+0.46in RaC due to processing of tissue, Where RaCβ, the corrected RaC, had a mean of 1.31±0.21μm. CONCLUSIONS Independently, freezing, fixation and dehydration do not alter the surface roughness of coronary arteries. Combined, however, fixation and dehydration significantly increase the circumferential, but not longitudinal, surface roughness of coronary arteries.
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Outzen EM, Zaki M, Abdolalizadeh B, Sams A, Boonen HCM, Sheykhzade M. Translational value of mechanical and vasomotor properties of mouse isolated mesenteric resistance-sized arteries. Pharmacol Res Perspect 2015; 3:e00200. [PMID: 27022471 PMCID: PMC4777254 DOI: 10.1002/prp2.200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 11/06/2015] [Indexed: 11/09/2022] Open
Abstract
Mice are increasingly used in vascular research for studying perturbations and responses to vasoactive agents in small artery preparations. Historically, small artery function has preferably been studied in rat isolated mesenteric resistance-sized arteries (MRA) using the wire myograph technique. Although different mouse arteries have been studied using the wire myograph no establishment of optimal settings has yet been performed. Therefore, the purposes of this study were firstly to establish the optimal settings for wire myograph studies of mouse MRA and compare them to those of rat MRA. Second, by surveying the literature, we aimed to evaluate the overall translatability of observed pharmacological vasomotor responses of mouse MRA to those obtained in rat MRA as well as corresponding and different arteries in terms of vessel size and species origin. Our results showed that the optimal conditions for maximal active force development in mouse MRA were not significantly different to those determined in rat MRA. Furthermore, we found that the observed concentration-dependent vasomotor responses of mouse MRA to noradrenaline, phenylephrine, angiotensin II, sarafotoxin 6c, 5-hydroxytryptamine, carbachol, sodium nitroprusside, and retigabine were generally similar to those described in rat MRA as well as arteries of different sizes and species origin. In summary, the results of this study provide a framework for evidence-based optimization of the isometric wire myograph setup to mouse MRA. Additionally, in terms of translational value, our study suggests that mouse MRA can be applied as a useful model for studying vascular reactivity.
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Affiliation(s)
- Emilie M. Outzen
- Department of Drug Design and PharmacologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Marina Zaki
- Department of Drug Design and PharmacologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Bahareh Abdolalizadeh
- Department of Drug Design and PharmacologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Anette Sams
- Department of Diabetic Complications BiologyNovo Nordisk A/SMaaloevDenmark
| | - Harrie C. M. Boonen
- Department of Drug Design and PharmacologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Majid Sheykhzade
- Department of Drug Design and PharmacologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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3
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Cyclooxygenase metabolism mediates vasorelaxation to 2-arachidonoylglycerol (2-AG) in human mesenteric arteries. Pharmacol Res 2014; 81:74-82. [PMID: 24548820 PMCID: PMC3992009 DOI: 10.1016/j.phrs.2014.02.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 01/19/2014] [Accepted: 02/03/2014] [Indexed: 01/04/2023]
Abstract
Objective The vasorelaxant effect of 2-arachidonoylglycerol (2-AG) has been well characterised in animals. 2-AG is present in human vascular cells and is up-regulated in cardiovascular pathophysiology. However, the acute vascular actions of 2-AG have not been explored in humans. Approach Mesenteric arteries were obtained from patients receiving colorectal surgery and mounted on a myograph. Arteries were contracted and 2-AG concentration–response curves were carried out. Mechanisms of action were characterised pharmacologically. Post hoc analysis was carried out to assess the effects of cardiovascular disease/risk factors on 2-AG responses. Results 2-AG caused vasorelaxation of human mesenteric arteries, independent of cannabinoid receptor or transient receptor potential vanilloid-1 activation, the endothelium, nitric oxide or metabolism via monoacyglycerol lipase or fatty acid amide hydrolase. 2-AG-induced vasorelaxation was reduced in the presence of indomethacin and flurbiprofen, suggesting a role for cyclooxygenase metabolism 2-AG. Responses to 2-AG were also reduced in the presence of Cay10441, L-161982 and potentiated in the presence of AH6809, suggesting that metabolism of 2-AG produces both vasorelaxant and vasoconstrictor prostanoids. Finally, 2-AG-induced vasorelaxation was dependent on potassium efflux and the presence of extracellular calcium. Conclusions We have shown for the first time that 2-AG causes vasorelaxation of human mesenteric arteries. Vasorelaxation is dependent on COX metabolism, activation of prostanoid receptors (EP4 & IP) and ion channel modulation. 2-AG responses are blunted in patients with cardiovascular risk factors.
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Müller-Schweinitzer E. Cryopreservation of vascular tissues. Organogenesis 2012; 5:97-104. [PMID: 20046671 DOI: 10.4161/org.5.3.9495] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2009] [Accepted: 07/08/2009] [Indexed: 12/22/2022] Open
Abstract
Cryopreservation of human blood vessels may become an important tool in bypass surgery and peripheral vascular reconstruction. Ideally cryopreservation of a blood vessel should preserve functional characteristics comparable to those of fresh controls. The key advantage of cryopreservation is the fact that storage at deep subzero temperatures allows storage of structurally intact living vascular tissues for virtually infinite time. Originally developed for long-time storage of isolated cells, the techniques of cryopreservation of tissues are challenged by the fact that these are complex multicellular systems containing diverse types of cells with differing requirements for optimal preservation. Therefore, the post-thaw functional activity of vascular tissues is determined by the type of blood vessel and, in addition, by the cell packing effect. Moreover, evidence from pharmacological studies suggests that cryopreservation induces tissue specific changes in transmembrane signaling and the mechanisms coupling intracellular calcium release, sensitivity and calcium entry into the smooth muscle cells.
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Affiliation(s)
- Else Müller-Schweinitzer
- Heart Surgery Center Basel-Bern; University Hospital and Department of Biomedicine; Basel, Switzerland
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Elami A, Gavish Z, Korach A, Houminer E, Schneider A, Schwalb H, Arav A. Successful restoration of function of frozen and thawed isolated rat hearts. J Thorac Cardiovasc Surg 2008; 135:666-72, 672.e1. [DOI: 10.1016/j.jtcvs.2007.08.056] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 07/29/2007] [Accepted: 08/02/2007] [Indexed: 11/17/2022]
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Müller-Schweinitzer E, Striffeler H, Grussenmeyer T, Reineke DC, Glusa E, Grapow MTR. Impact of freezing/thawing procedures on the post-thaw viability of cryopreserved human saphenous vein conduits. Cryobiology 2007; 54:99-105. [PMID: 17239362 DOI: 10.1016/j.cryobiol.2006.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 11/12/2006] [Accepted: 11/22/2006] [Indexed: 11/24/2022]
Abstract
BACKGROUND Cryopreserved human blood vessels are important tools in reconstructive surgery. However, patency of frozen/thawed conduits depends largely on the freezing/thawing procedures employed. METHODS Changes in tone were recorded on rings from human saphenous vein (SV) and used to quantify the degree of cryoinjury after different periods of exposure at room temperature to the cryomedium (Krebs-Henseleit solution containing 1.8M dimethyl sulfoxide and 0.1M sucrose) and after different cooling speeds and thawing rates following storage at -196 degrees C. RESULTS Without freezing, exposure of SV to the cryomedium for up to 240 min did not modify contractile responses to noradrenaline (NA). Pre-freezing exposure to the cryomedium for 10-120 min attenuated significantly post-thaw maximal contractile responses to NA, endothelin-1 (ET-1) and potassium chloride (KCl) by 30-44%. Exposure for 240 min attenuated post-thaw contractile responses to all tested agents markedly by 62-67%. Optimal post-thaw contractile activity was obtained with SV frozen at about -1.2 degrees C/min and thawed slowly at about 15 degrees C/min. In these SV maximal contractile responses to NA, ET-1 and KCl amounted to 66%, 70% and 60% of that produced by unfrozen controls. Following cryostorage of veins for up to 10 years the responsiveness of vascular smooth muscle to NA was well maintained. CONCLUSION Cryopreservation allows long-term banking of viable human SV with only minor loss in contractility.
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Pasquinelli G, Pistillo MP, Ricci F, Buzzi M, Tazzari PL, Foroni L, Manferdini C, Ceccarelli C, Stella A, Conte R. The “in situ” expression of Human Leukocyte Antigen Class I antigens is not altered by cryopreservation in human arterial allografts. Cell Tissue Bank 2006; 8:195-203. [PMID: 17063259 DOI: 10.1007/s10561-006-9025-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Accepted: 07/20/2006] [Indexed: 10/24/2022]
Abstract
This study was aimed to establish whether the cryopreservation procedure we currently use in clinics can modify arterial homograft antigenicity. To this purpose, we performed an immunohistochemical study on fresh and cryopreserved human arterial homografts to visualize the expression of HLA class I heavy and light chains "in situ" by using the HC-10 and Namb-1 monoclonal antibodies. Human femoral arteries and thoracic aortas were harvested from 18 heart-beating donors and sampled before and after cryopreservation. Arterial segments were frozen in liquid nitrogen vapors in a controlled rate freezing system. After thawing, samples were processed for routine immunohistochemistry. To standardize immunostaining, flow-cytometry indirect immunofluorescence analysis was performed on HUVEC; immunohistochemistry of human ovarian cortical vessels was performed as an additional positive control. Negative controls were performed by omitting tissue incubation with primary antibodies. HLA-class I antigens were markedly expressed by endothelial cells lining surface intima and adventitial vasa vasorum; a moderate expression was found in medial smooth muscle cells. Except for the surface unreactivity caused by loss of endothelium, results from cryopreserved arterial allografts were strictly comparable to those observed in fresh, unfrozen tissues. These results support the view that cryopreserved arterial allografts are immunogenic as their fresh counterparts; apart from smooth muscle cells which retained a moderate expression of HLA class I antigens following cryopreservation, our study suggests that the highly HC-10 positive endothelial cells we found to line the rich adventitial network of vasa vasorum are expected to be one of the major targets of the serological response in the recipient.
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Affiliation(s)
- G Pasquinelli
- Clinical Pathology Unit, Department of Experimental Pathology, Policlinico S. Orsola, University of Bologna, Blg 11, via Massarenti 9, 40138, Bologna, Italy.
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Pasquinelli G, Foroni L, Buzzi M, Tazzari PL, Vaselli C, Mirelli M, Gargiulo M, Conte R, Stella A. Smooth muscle cell injury after cryopreservation of human thoracic aortas. Cryobiology 2006; 52:309-16. [PMID: 16458877 DOI: 10.1016/j.cryobiol.2005.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 12/19/2005] [Accepted: 12/21/2005] [Indexed: 11/20/2022]
Abstract
The cryopreservation protocol we use for arterial reconstructive surgery has been studied to evaluate smooth muscle cell (SMC) structural integrity and viability before implantation. Samples of human thoracic aortas (HTA) were harvested from five multi-organ donors. Sampling included unfrozen and cryopreserved specimens. Cryopreservation was performed using RPMI with human albumin and 10% Me(2)SO in a controlled-rate freezing apparatus. Thawing was accomplished by submerging bags in a water bath (39 degrees C) followed by washings in cooled saline. In situ cell preservation as investigated by light and transmission electron microscopy showed that SMCs from cryopreserved HTA had nuclear and cytoplasmic changes. A TUNEL assay, performed to detect DNA fragmentation in situ, showed increased SMC nuclear positivity in cryopreserved HTA when compared to unfrozen samples. 7-AAD flow cytometry assay of cells derived from cryopreserved HTA showed that an average of 49+/-16% cells were unlabeled after cryopreservation. Organ cultures aimed to study cell ability to recover cryopreservation damage showed a decreasing number of SMCs from day 4 to day 15 in cryopreserved HTA. In conclusion, the cryopreservation protocol applied in this study induces irreversible damage of a significant fraction of arterial SMCs.
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Affiliation(s)
- G Pasquinelli
- Clinical Pathology, Department of Experimental Pathology, University of Bologna, Policlinico S. Orsola-Malpighi, Italy.
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Müller-Schweinitzer E, Grapow M, Konerding MA, Zerkowski HR. Freezing without surrounding cryomedium preserves the endothelium and its function in human internal mammary arteries. Cryobiology 2005; 51:54-65. [PMID: 15936748 DOI: 10.1016/j.cryobiol.2005.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 04/07/2005] [Accepted: 04/14/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE Cryopreserved human blood vessels may become important tools in bypass surgery. Optimal cryopreservation of an arterial graft should, therefore, preserve both histological and physiological characteristics of smooth muscle and endothelium comparable to the unfrozen artery. METHODS Rings from human internal mammary arteries (IMA) were investigated in vitro either unfrozen or after immersion into a cryomedium (RPMI 1640 containing 1.8M Me2SO and 0.1M sucrose) and cryostorage with and without surrounding medium. RESULTS In unfrozen IMA, neither contractile responses to noradrenaline (NA) nor endothelium-dependent relaxant responses to acetylcholine (ACH) was modified after exposure of the IMA to cryomedium or during activation of protein kinase C by phorbol-12,13-dibutyrate (PDBu). Exposure to cryomedium with gradually increasing Me2SO content before starting the cooling process did not improve the post-thaw functional activity of the artery. Optimal post-thaw recovery of contractile responses to NA and PGF(2alpha) was observed after freezing at a speed of -1.2 and -3 degrees C/min in arteries stored with and without surrounding cryomedium. Compared to unfrozen controls, the ACH-induced endothelium-dependent relaxation during active tone induced by 3 microM PGF(2alpha) reached 16 and 56% after freezing with and without surrounding medium. All functional data were reflected by electron microscopy images showing considerably better preservation of the endothelial layer after freezing without medium. CONCLUSION Freezing of human arteries at a mean cooling rate of -3 degrees C/min and storage without surrounding medium offers the prospect of optimal preservation of both smooth muscle and endothelial function in cryopreserved human IMA.
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Rendal E, Santos MVM, Rodriguez M, Sánchez J, Segura R, Matheu G, Filgueira P, Pértega S, Andión C. Effects of cryopreservation and thawing on the structure of vascular segment. Transplant Proc 2005; 36:3283-7. [PMID: 15686746 DOI: 10.1016/j.transproceed.2004.10.057] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The objective of this study was to analyze the importance of the quality of the vascular segment to be cryopreserved and the influence of storage in a gas phase, a liquid phase, or after accidental immersion in liquid nitrogen. In addition, we investigated the effects of rapid versus slow thawing on the occurrence of fractures and changes in the structure of the vessel wall. The tissue sources were whole thoracic and abdominal aortas from 15 pigs. Each aorta was cut into equal segments and randomly assigned to each study group. One segment of fresh unfrozen aorta of the same size was used as a control. The samples were cryopreserved using a programmed apparatus. After 2 weeks the arterial segments were thawed rapidly or slowly. A great variation in the results was obtained depending on the quality of the control. Although endothelial cells were better preserved in the liquid phase, the internal elastic lamina and elastic lamelli showed better preservation and fewer microfractures in the gas phase. The internal elastic lamina showed a greater number of microfractures when an accidental immersion in liquid nitrogen had taken place. Furthermore, better preservation of the structure of the vascular segment was observed with a slow thawing method. In general, the conditions of storage and the method of thawing seem to damage the structure of vascular segments. It is necessary to use a severe protocol of donor and vascular segment selection to optimize the post-thaw quality of the cryopreserved samples.
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Affiliation(s)
- E Rendal
- Cryobiology Unit, Complejo Hospitalario Juan Canalejo, La Coruña, Spain.
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11
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Wang P, Shu Z, He L, Wang Y, Cui X, Yu J, Lu J, Gao D. The Viability, Structure, and Mechanical Properties of Cryopreserved Rabbit Carotid Artery. ACTA ACUST UNITED AC 2005. [DOI: 10.1089/cpt.2005.3.85] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Peitao Wang
- School of Life Science, University of Science and Technology of China (USTC), Hefei, China
- Department of Thermal Science and Energy Engineering, University of Science and Technology of China (USTC), Hefei, China
| | - Zhiquan Shu
- Department of Thermal Science and Energy Engineering, University of Science and Technology of China (USTC), Hefei, China
| | - Liqun He
- Department of Thermal Science and Energy Engineering, University of Science and Technology of China (USTC), Hefei, China
| | - Yuzhen Wang
- School of Life Science, University of Science and Technology of China (USTC), Hefei, China
| | - Xiangdong Cui
- Department of Mechanical Engineering and Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky
| | - Jianping Yu
- Department of Mechanical Engineering and Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky
| | - Junfeng Lu
- Department of Mechanical Engineering and Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky
| | - Dayong Gao
- Department of Thermal Science and Energy Engineering, University of Science and Technology of China (USTC), Hefei, China
- Department of Mechanical Engineering and Center for Biomedical Engineering, University of Kentucky, Lexington, Kentucky
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Fahner PJ, Idu MM, Legemate DA, Vanbavel E, Borstlap J, Pfaffendorf M, van Marle J, van Gulik TM. Morphological and functional alterations in glycerol preserved rat aortic allografts. Int J Artif Organs 2005; 27:979-89. [PMID: 15636056 DOI: 10.1177/039139880402701111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Glycerol preservation is an effective method for long-term preservation of skin allografts and has a potential use in preserving arterial allografts. We evaluated the effect of glycerol concentration and incubation period on vessel-wall integrity of rat aortic allografts. No significant differences were measured in breaking strength (2.3 +/- 0.3 N) and bursting pressure (223 +/- 32 kPa) between standard glycerolized and control segments (1.7 +/- 0.3 N, 226 +/- 17 kPa). Isometric tension measurements showed complete lack of functional contraction and relaxation capacity in allograft segments prepared according to all preservation protocols. Morphologically, thickness of the vessel-wall media diminished after preservation using low (30/50/75%) or high (70/85/98%) concentrations of glycerol, as compared to control segments (i.e. 81 +/- 2.4 microm, 95 +/- 5.6 microm and 125 +/- 3.5 microm, respectively). Confocal microscopy and Fourier analysis demonstrated that vascular collagen and elastin bundle orientation had remained unaltered. Electron microscopy showed defragmentation of luminal endothelial cells. In conclusion, glycerol preservation of rat aorta resulted in an acellular tissue matrix, which maintained biomechanical integrity and extracellular matrix characteristics. The next step in the investigation will be to test the concept of glycerol preservation of arterial allografts in a vascular transplantation model.
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Affiliation(s)
- P J Fahner
- Department of Surgery and Surgical Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Pascual G, Escudero C, Rodríguez M, Corrales C, Serrano N, Bellón JM, Buján J. Restoring the endothelium of cryopreserved arterial grafts: co-culture of venous and arterial endothelial cells. Cryobiology 2004; 49:272-85. [PMID: 15615613 DOI: 10.1016/j.cryobiol.2004.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2004] [Accepted: 09/16/2004] [Indexed: 11/15/2022]
Abstract
The use of arterial homografts in clinical practice is becoming increasingly common, yet there is an urgent need to address one of the most well-established problems associated with their use: the loss of integrity of the endothelium following cryopreservation. The partial lack of endothelium causes contact between the extracellular matrix and blood flow, which, in turn, often gives rise to thrombosis and/or restenosis. Our objective was first to attempt to replace the arterial endothelial cells lost during the cryopreservation process by seeding autologous venous endothelial cells, and to evaluate the behaviour of venous and arterial endothelial cells in co-culture. The idea was to establish whether venous endothelial cells would be accepted by arterial endothelial cells and could therefore be used to restore the endothelial lining for the subsequent use of these vessels in in vivo grafting procedures. For the co-culture experiments, endothelial cells were obtained from the jugular vein and both iliac arteries of the minipig by treatment with 0.1% type I collagenase. The venous endothelial cells were fluorescently labelled with the membrane intercalating dye PKH26. Equal numbers of venous and arterial endothelial cells were mixed and co-cultured for 24h, 48h or 4 days. Cell viability, determined by 2% trypan blue staining and the TUNEL method, was established before and after fluorescence labelling. Cellular activity was determined by estimating PGI2 levels in the cultures. The proliferation index was established by [H(3)]thymidine (1muCi/ml) in the cell culture medium. For the in vivo tests, 5 cm length segments of minipig iliac artery were used to establish the groups: control (n = 6), fresh arterial segments; group I (n = 16), cryopreserved arterial segments and group II (n = 16), cryopreserved arterial segments seeded with autologous venous endothelial cells. The cryopreserved vessels in group II were seeded by flooding with a labelled venous endothelial cell suspension. Once seeded, the arterial segments were included in an in vitro flow circuit. All the specimens were processed for fluorescence and light microscopy, and scanning electron microscopy. The denuded endothelial surface was determined in each group. Cell death was evaluated by the TUNEL method. We confirmed the existence of intercellular PECAM1-type junctions between venous (PKH26+) and arterial cells in co-culture and the functional activity of the cells. The cryopreserved arterial segments showed a well-preserved wall structure. However, different size areas of marked endothelial denudation were detected. After seeding with labelled cells (PKH26+), these denuded areas of the cryopreserved artery were entirely covered by fluorescent cells. After seeding, a drop in the proportion of damaged endothelial cells was recorded. Despite some loss of seeded cells after inclusion in the in vitro flow circuit, the endothelial cell count was not significantly different to those recorded for control, non-cryopreserved specimens. In conclusion arterial and venous endothelial cells growing in co-culture modify their behaviour to form multilayers. The two cell populations form normal PECAM1 junctions and preserve their functional properties. Seeding autologous venous endothelial cells on the luminal surface of cryopreserved arterial segments serves to restore the integrity of the endothelial layer.
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Affiliation(s)
- Gemma Pascual
- Department of Medical Specialities, Faculty of Medicine, University of Alcala, Alcalá de Henares, Madrid, Spain
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Rendal E, Rodríguez M, Martínez MV, Fernández RO, Sánchez J, Segura R, Bermúdez T, Matheu G, Filgueira P, Pértega S, Andión C. Function of cryopreserved pig aortas. J Surg Res 2004; 120:304-11. [PMID: 15234227 DOI: 10.1016/j.jss.2004.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2003] [Indexed: 11/18/2022]
Abstract
OBJECTIVES This paper analyzes the influence of storage in the gas phase or liquid phase on grafts, together with the thawing method (15 degrees C/min or 100 degrees C/min) on the postthawing activity of pig cryopreserved arterial grafts (aortas). MATERIALS AND METHODS Obtainment of arterial grafts (aortas) was from pigs with an ischemic time not greater than 2 h. Each aorta was divided into five fragments and assigned randomly to one control group of fresh aorta and four groups of cryopreserved aortas: group 1: gas phase/slow thawing; group 2: gas phase/rapid thawing; group 3: liquid phase/slow thawing; and group 4: liquid phase/rapid thawing. After the incubation in antibiotic solution, the cryopreservation in RPMI medium +10% DMSO was carried out and the level of cooling used was a reduction of 1 degrees C/min. The contraction and relaxation responses of the fresh and frozen/thawed arteries were carried out in organ baths. RESULTS After thawing, the sensitivity to various agonists and maximal responses to the endothelium-dependent and independent relaxant agents were decreased. The maximal responses to the tested vasoconstrictors (KCl and noradrenaline) were, respectively, 13% and 24% of the responses obtained in unfrozen aortas. The endothelium-independent relaxant responses to sodium nitroprusside (SNP) were reduced and important reductions of the endothelium-dependent relaxant responses to acetylcholine were produced. CONCLUSIONS The cryopreservation of pig aortas under the conditions used in this study led to a decrease in the contractility of the pig aortas, as well as a decrease in the endothelium-independent relaxant responses. On the other hand, no apparent preservation of the endothelium-dependent relaxant responses was observed.
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Affiliation(s)
- E Rendal
- Cryobiology Unit, Complejo Hospitalario Juan Canalejo, Carretera del Pasaje s/n, Hospital Teresa Herrera, 15006 La Coruña, Spain.
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Esther Rendal Vázquez M, Rodríguez Cabarcos M, Fernández Mallo RO, Sánchez Ibáñez J, Segura Iglesias R, Bermúdez González T, Matheu Capó G, Filgueira Fernández P, Pértega Díaz S, Andión Núñez C. Functional assessment of human femoral arteries after cryopreservation. Cryobiology 2004; 49:83-9. [PMID: 15265718 DOI: 10.1016/j.cryobiol.2004.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2002] [Accepted: 04/19/2004] [Indexed: 10/26/2022]
Abstract
An established method for the cryopreservation of human femoral arteries for subsequent transplantation as allografts has been studied with particular attention to preservation of smooth muscle and endothelium. Human femoral arteries (HFAs) were harvested from multi-organ donors. Two groups were established; a control group of unfrozen HFAs and a group of cryopreserved HFAs. Cryopreservation was performed using RPMI solution containing dimethyl sulfoxide and the rate of cooling was 1 degrees C/min to -40 degrees C and faster thereafter until -150 degrees C was reached. The contraction and relaxation responses of unfrozen and frozen/thawed arteries were assessed by measurement of the isometric force generated by the HFAs in an organ bath. After thawing (warming was at 15 degrees C/min) the maximal contractile response to noradrenaline was 43% of the response of unfrozen HFAs. The endothelium-independent response to sodium nitroprusside was not altered, whereas the endothelium-dependent relaxation response to acetylcholine was slightly altered. The cryopreservation method used provided limited preservation of the contractility of human femoral arteries, and good preservation of both endothelium-independent and endothelium-dependent relaxation responses.
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Pascual G, Rodríguez M, Corrales C, Turégano F, García-Honduvilla N, Bellón JM, Buján J. New approach to improving endothelial preservation in cryopreserved arterial substitutes. Cryobiology 2004; 48:62-71. [PMID: 14969683 DOI: 10.1016/j.cryobiol.2003.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2003] [Accepted: 12/17/2003] [Indexed: 11/21/2022]
Abstract
The endothelial loss provoked by the methods of vascular cryopreservation used at most human vessel banks is one of the main factors leading to the failure of grafting procedures performed using cryopreserved vessel substitutes. This study evaluates the effects of the storage temperature and thawing protocol on the endothelial cell loss suffered by cryopreserved vessels, and optimises the thawing temperature and protocol for cryopreserving arterial grafts in terms of that producing least endothelial loss. Segments of the common iliac artery of the minipig (n = 20) were frozen at a temperature reduction rate of 1 degrees C/min in a biological freezer. After storing the arterial fragments for 30 days, study groups were established according to the storage temperature (-80, -145 or -196 degrees C) and subsequent thawing procedure (slow or rapid thawing). Fresh vessel segments served as the control group. Once thawed, the specimens were examined by light, transmission, and scanning electron microscopy. The covered endothelial surface was determined by image analysis. Data for the different groups were compared by one way ANOVA. When cryopreservation at each of the storage temperatures was followed by slow thawing, the endothelial cells showed improved morphological features and viability over those of specimens subjected to rapid thawing. Rapidly thawed endothelial cells showed irreversible ultrastructural damage such as mitochondrial dilation and rupture, reticular fragmentation, and peripheral nuclear condensation. In contrast, slow thawing gave rise to changes compatible with reversible damage in a large proportion of the endothelial cells: general swelling, reticular dilation, mitochondrial swelling, and nuclear chromatin condensation. Gradually thawed cryopreserved arteries showed a lower proportion of damaged cells identified by the TUNEL method compared to the corresponding rapidly thawed specimens (p < 0.05, for all temperatures). In all the groups in which vessels underwent rapid thawing (except at -145 degrees C), significant differences (p < 0.05) in endothelial cover values were recorded with respect to control groups. Storage of cryopreserved vessels at -80 degrees C followed by rapid thawing led to greatest endothelial cell loss (61.36+/-9.06% covered endothelial surface), while a temperature of -145 degrees C followed by slow thawing was best at preserving the endothelium of the vessel wall (89.38+/-16.67% surface cover). In conclusion, storage at a temperature of -145 degrees C in nitrogen vapour followed by gradual automated thawing seems to be the best way of preserving the endothelial surface of the arterial cryograft. This method gives rise to best endothelial cell viability and cover values, with obvious benefits for subsequent grafting.
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Affiliation(s)
- Gemma Pascual
- Department of Medical Specialities, Faculty of Medicine, University of Alcala, E-28871 Alcalá de Henares, Madrid, Spain
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Veiga-Barreiro A, Rendal-Vázquez M, Matheu-Capó G, Andión-Núñez C, Sánchez-Ibáñez J, Segura-Iglesias R, Filgueira-Fernández P, Pértega-Díaz S, Rodríguez-Cabarcos M, Fernández-Mallo R, Bermúdez-González T, Fiaño-López V, Vázquez-Blanco M, Vázquez-Martul E. Cambios histopatólogicos en arterias humanas sometidas a procesos de isquemia fría y criopreservación. ANGIOLOGIA 2004. [DOI: 10.1016/s0003-3170(04)74854-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rendal-Vázquez M, Rodríguez-Cabarcos M, Fernández-Mallo R, Sánchez-Ibáñez J, Segura-Iglesias R, Veiga-Barreiro A, Filgueira-Fernández P, Pértega-Díaz S, Bermúdez-González T, Andión-Núñez C. Efecto del almacenamiento en fase gaseosa sobre la viabilidad celular, la apoptosis y la actividad funcional en aortas de cerdo criopreservadas. Estudio preliminar. ANGIOLOGIA 2004. [DOI: 10.1016/s0003-3170(04)74855-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Cui X, Labarrere C, He L, Cheng S, Siderys H, Kovacs R, Gao D. Cryopreservation and Microsurgical Implantation of Rabbit Carotid Arteries. ACTA ACUST UNITED AC 2002. [DOI: 10.1089/153834402320882629] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Pascual G, García-Honduvilla N, Rodríguez M, Turégano F, Bujan J, Bellón JM. Effect of the thawing process on cryopreserved arteries. Ann Vasc Surg 2001; 15:619-27. [PMID: 11769142 DOI: 10.1007/s100160010130] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
This study was designed to explore the changes that occur in cryopreserved pig arteries following different thawing procedures, before and after being placed in an in vitro flow circuit. Segments of minipig iliac artery were cryopreserved in complete minimal essential medium plus 10% dimethylsulphoxide and stored in liquid nitrogen at -196 degrees C for 30 days. Three study groups were established according to whether the arterial specimens were fresh (control, n = 20), cryopreserved and rapidly thawed (RT) at 37 degrees C (n = 22) or cryopreserved and subjected to controlled, automated slow thawing (ST) (n = 22). Half of the specimens of each group were subsequently placed in the flow circuit for 72 hr. Evaluation was made of morphological and ultrastructural changes. Cell damage was established using the TUNEL method. All cryopreserved specimens showed endothelial denudation that was most extensive in those subjected to rapid thawing. Slowly thawed specimens showed improved cell viability and organization of the vessel wall, compared to those thawed rapidly. Under conditions of flow, the damage induced by the freezing/thawing process was enhanced. These findings suggest that (a) slow thawing of cryopreserved arteries results in improved preservation of the structure and viability of vessels, and (b) the damage induced by freezing/thawing is enhanced when vessels are subjected to flow in an in vitro circuit.
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Affiliation(s)
- G Pascual
- Department of Morphological Sciences and Surgery (Surgical Research Laboratory), Medical School, University of Alcala, Crta. Madrid-Barcelona Km 33,600, E-28871 Alcalá de Henares, Madrid, Spain
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21
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Langerak SE, Groenink M, Wall EE, Wassenaar C, Vanbavel E, Spaan JAE, Baal MC. Impact of current cryopreservation procedures on mechanical and functional properties of human aortic homografts. Transpl Int 2001. [DOI: 10.1111/j.1432-2277.2001.tb00053.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Buján J, Pascual G, García-Honduvilla N, Gimeno MJ, Jurado F, Carrera-San Martín A, Bellón JM. Rapid thawing increases the fragility of the cryopreserved arterial wall. Eur J Vasc Endovasc Surg 2000; 20:13-20. [PMID: 10906291 DOI: 10.1053/ejvs.2000.1090] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To extend present knowledge of the biomechanical and structural changes which occur in the cryopreserved, rapidly thawed arterial wall. MATERIALS AND METHODS Minipig iliac arterial segments were cryopreserved at -196 degrees C in either minimum essential medium or Wisconsin solution. Fresh segments served as the control group. After 1 month, the specimens were rapidly thawed (37 degrees C) and processed for biomechanical, ultrastructural, morphological and immunohistochemical (MMP-1, MMP-2, MMP-3 and MMP-9) analysis. Visualisation of apoptotic cells was performed by TUNEL method. For the mechanical distension analysis, an in vitro circuit was designed. RESULTS The cryopreserved segments showed a 42% incidence of spontaneous fracture and the appearance of microfractures which affected the endoluminal third of the vessel. An accumulation of liquid in the subelastica was observed. An increased expression of wall-degradative enzymes (mainly MMP-2) was also observed following cryopreservation. No significant differences were detected in the proportional elasticity module or tensile strength of the specimen groups. No differences in mechanical distension were observed between groups after the vessel segments were subjected to the pulsatile circuit flow for 72 h. Cell damage was most intense in the specimens cryopreserved in Wisconsin solution. CONCLUSIONS Cryopreservation in both the solutions employed, followed by rapid thawing, induce changes in the permeability which increase the fragility of the cryopreserved arterial wall. Both increased expression of wall-degradative enzymes and accumulation of liquid may contribute to graft failure after implantation.
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Affiliation(s)
- J Buján
- Department of Morphological Sciences and Surgery (Surgical Research Laboratory), Medical School, University of Alcalá, Madrid, Spain
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Müller-Schweinitzer E, Brett W, Zerkowski HR, Haefeli WE. The mechanism of cryoinjury: In vitro studies on human internal mammary arteries. Br J Pharmacol 2000; 130:636-40. [PMID: 10821792 PMCID: PMC1572092 DOI: 10.1038/sj.bjp.0703326] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The mechanism of cryoinjury was investigated in human internal mammary arteries (IMA) by monitoring contractile responses to ET-1 and KCl. For cryopreservation segments of IMA were equilibrated for 20 min with the cryomedium (RPMI 1640 culture medium containing 1.8 M DMSO and 0.1 M sucrose), frozen at a mean cooling rate of 1.3 degrees C min(-1) to -70 degrees C and stored in liquid nitrogen. Before use, samples were thawed slowly and the cryomedium removed by dilution. Compared to unfrozen controls, ET-1 stimulated frozen/thawed IMA with similar efficacy but at 3 fold lower concentrations (P<0.001). Addition of ET-1 (100 nM) induced maximal contraction of unfrozen IMA within 10 min, declining thereafter to 25% after 90 min. In frozen/thawed IMA the ET-1-induced contraction was sustained but could be reversed if protein kinase C was blocked by staurosporine (100 nM). Responses to ET-1 of cryostored IMA were 5 fold more susceptible to blockade by nifedipine than those of controls. After cryostorage the efficacy of KCl was diminished to 40% (P<0.05) and the KCl curve was shifted to the left (2 fold, P<0. 001). In both unfrozen and cryostored IMA the KCl (60 mM) effect was sustained and equally susceptible to nifedipine. It is suggested that the smooth muscle cell of IMA is receptive to physical forces which occur during cryopreservation. These forces modify transmembrane signal transduction and intracellular pathways, that are common to pharmacological agonists thereby changing vascular responses to several contractile agonists after thawing.
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Affiliation(s)
- E Müller-Schweinitzer
- Division of Clinical Pharmacology, Department of Internal Medicine, Kantonsspital, University Hospital, CH-4031 Basel, Switzerland.
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Rigol M, Heras M, Martínez A, Zurbano MJ, Agustí E, Roig E, Pomar JL, Sanz G. Changes in the cooling rate and medium improve the vascular function in cryopreserved porcine femoral arteries. J Vasc Surg 2000; 31:1018-25. [PMID: 10805894 DOI: 10.1067/mva.2000.103793] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE The purpose of this study was to design an adequate technique with which to cryopreserve pig femoral arteries and to assess the influence of storage times in vascular function. METHODS Fifty-two femoral arteries were distributed in seven groups. In group A (control), 10 arteries were studied after harvest; in groups B1 and B2, 19 arteries were suspended in RPMI 1640 plus fetal calf serum plus dimethylsulfoxide and were cryopreserved at 1 degrees C per minute or 0.3 degrees C per minute, respectively. In groups C1 to C4, 23 arteries were suspended in modified Krebs-Henseleit plus dimethylsulfoxide plus sucrose, cryopreserved at 0.7 degrees C per minute, and kept frozen for 1, 15, 60, or 180 days, respectively. After being thawed, arteries were examined for contraction and endothelial-dependent vasodilation (organ bath studies), antithrombotic properties of the endothelial layer(perfusion studies), and vessel structure (electron microscopy). RESULTS Endothelial cells were present in both cryopreserved and control arteries. The control vessels showed a mean contraction to norepinephrine (10(-7) mol/L) of 13010 +/- 3181 mg. Arteries in groups B1 and B2 did not respond to norepinephrine. Contraction in groups C1 to C4 was as follows: C1, 5354 +/- 1222 mg; C2, 5187 +/- 2672 mg; C3, 6867 +/- 2292 mg; C4, 7000 +/- 2858 mg, which represent 50% of the control values (P <.001). Vasodilation was similar in control (99% +/- 3%) and cryopreserved arteries (C1, 90% +/- 13%; C2, 93% +/- 12%; C3, 89% +/- 15%; C4, 88% +/- 22%). Storage time did not influence vascular function. Platelet interaction was almost absent and similar in all groups. CONCLUSION A modified cryopreservation technique preserves endothelial function independently of the storage time up to 6 months.
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Affiliation(s)
- M Rigol
- Cardiovascular Institute, Hospital Clinic, and Institut d'Investigacions Biomèdiques August Pi Sunyer (IDIBAPS), University of Barcelona, Spain
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Bellón JM, Gimeno MJ, Pascual G, Garcia-Honduvilla N, Dominguez B, Buján J. Arterial damage induced by cryopreservation is irreversible following organ culture. Eur J Vasc Endovasc Surg 1999; 17:136-43. [PMID: 10063409 DOI: 10.1053/ejvs.1998.0739] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES The aim of the present study was to investigate the changes which occur to the arterial wall following cryopreservation and thawing and to determine whether these changes are reversible after a week of culture in an organ bath. MATERIALS AND METHODS Rat iliac arterial segments were cryopreserved. Once thawed, the arterial segments were cultured for a period of 0, 1, 2, 4 or 7 days. Freshly isolated rat iliac vessels cultured for 7 days served as the control group. Evaluation was made of ultrastructural changes, the expression of metalloproteinase activity (MMP-1, MMP-3 and MMP-9) and the apoptotic state of cells. RESULTS The freezing-thawing process induced damage to the arterial segments compared to fresh control vessels. After 1 week of culture, arteries showed a high degree of tissue degeneration. Only a few individual endothelial cells remained on the luminal surface. There was a gradual increase in the proportion of apoptotic cells. The sequential expression of MMP-1 during the first 2 days and subsequent expression of MMP-3 and MMP-9 were of most significance. CONCLUSIONS Cryopreservation induced damage to the vessels which could not be reversed by organ culture. The changes observed in the expression of metalloproteinases may be indicative of the degenerative process which occurs in the extracellular matrix.
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Affiliation(s)
- J M Bellón
- Department of Morphological Sciences and Surgery, Faculty of Medicine, University of Alcalá de Henares, Madrid, Spain
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TOGNINI JOÃORICARDOF, DANIELA NEVES, SOUZA ALEXSANDRODE, AYDOS RICARDODUTRA. EFEITO DA CONSERVAÇÃO POR FORMAS DE CONGELAMENTO NA AVALIAÇÃO DA FORÇA DE ROTURA DE CICATRIZES DA PAREDE ABDOMINAL DE RATOS. Acta Cir Bras 1998. [DOI: 10.1590/s0102-86501998000400010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
O objetivo deste trabalho foi o de estudar o efeito de duas formas de congelamento na avaliação da força de rotura de cicatrizes da parede abdominal de ratos. Foram utilizados 30 ratos machos Wistar, submetidos a laparotomia com técnica de diérese padronizada, distribuidos em 3 grupos com 10 ratos cada. No 14<FONT FACE="Symbol">°</FONT> dia de pós-operatório foram submetidos a eutanásia os ratos de dois grupos que tiveram segmentos músculo-fasciais da parede abdominal envolvendo a cicatriz cirúrgica, conservados em congelador a dezessete graus Célsius negativos (-17<FONT FACE="Symbol">°</FONT> C) ou em anidrido carbônico a oitenta graus célsius negativos (-80<FONT FACE="Symbol">°</FONT> C) por 20 dias antes de terem sidos submetidos a análise da força de rotura da cicatriz em um tensiômetro. O terceiro grupo (controle) foi submetido a eutanásia e imediatamente avaliado quanto a força de rotura. Os resultados encontrados foram analisados estatísticamente. Concluiu-se que as duas formas de congelamento não interferem na avaliação da força de rotura de cicatrizes da parede abdominal de ratos.
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Stanke F, Riebel D, Carmine S, Cracowski JL, Caron F, Magne JL, Egelhoffer H, Bessard G, Devillier P. Functional assessment of human femoral arteries after cryopreservation. J Vasc Surg 1998; 28:273-83. [PMID: 9719322 DOI: 10.1016/s0741-5214(98)70163-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE An established method of cryostorage that might preserve the vascular and endothelial responses of human femoral arteries (HFAs) to be transplanted as allografts was studied. METHODS HFAs were harvested from multiorgan donors and stored at 4 degrees C in Belzer solution before cryostorage. One hundred eleven HFA rings were isolated and randomly assigned to 1 control group of unfrozen HFAs and 2 groups of HFAs cryopreserved for 7 and 30 days, respectively. Cryopreservation was performed in Elohes solution containing dimethyl sulfoxide (1.8 mmol/L), and the rate of cooling was 1.6 degrees C/min, until -141 degrees C was reached. The contractile and relaxant responses of unfrozen and frozen/thawed arteries were assessed in organ bath by measurement of isometric force generated by the HFAs. RESULTS After thawing, the maximal contractile responses to all the contracting agonists tested (KCl, U46619 [a thromboxane A2-mimetic], norepinephrine, serotonin, and endothelin-1) were in the range of 7% to 34% of the responses in unfrozen HFAs. The endothelium-independent relaxant responses to forskolin and verapamil were weakly altered, whereas the endothelium-independent relaxant responses to sodium nitroprusside were markedly reduced. Cryostorage of HFAs also resulted in a loss of the endothelium-dependent relaxant response to acetylcholine. The vascular and endothelial responses were similarly altered in the HFAs cryopreserved for 7 and 30 days. CONCLUSION The cryopreservation method used provided a limited preservation of HFAs contractility, a good preservation of the endothelium-independent relaxant responses, but no apparent preservation of the endothelium-dependent relaxation. It is possible that further refinements of the cryopreservation protocol, such as a slower rate of cooling and a more controlled stepwise addition of dimethyl sulfoxide, might allow better post-thaw functional recovery of HFAs.
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Affiliation(s)
- F Stanke
- Laboratory of Pharmacology, PCEBM, Faculté de Médecine de Grenoble, and the Blood Transfusion Center, La Tronche, France
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Müller-Schweinitzer E, Stulz P, Striffeler H, Haefeli WE. Functional activity and transmembrane signaling mechanisms after cryopreservation of human internal mammary arteries. J Vasc Surg 1998; 27:528-37. [PMID: 9546240 DOI: 10.1016/s0741-5214(98)70328-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Cryopreserved human blood vessels are important tools in bypass surgery. However, several in vitro studies have demonstrated diminished postthaw functional activity. Therefore the aim of this study was to investigate the consequences of various freezing/thawing protocols and the role of protein kinase C in the postthaw functional activity of cryopreserved human arteries. METHODS In vitro responses of frozen/thawed human internal mammary arteries (IMA) were used to investigate the functional activity after thawing at 15 degrees, 30 degrees, and 100 degrees C/min and after different prefreezing equilibration times (10, 60, 120, 240 minutes) with the cryomedium (Krebs-Henseleit solution containing 1.8 mol/L dimethyl sulfoxide and 0.1 mol/L sucrose) at room temperature followed by cryostorage at -196 degrees C. RESULTS Prefreezing equilibration for 10 to 120 minutes diminished maximal alpha-adrenoceptor-mediated responses to noradrenaline to approximately 60%, and equilibration for 240 minutes attenuated noradrenaline effects to less than 25% of that produced by unfrozen controls. Contractile responses were slightly better when thawing was performed at 15 degrees C/min compared with 100 degrees C/min. The postthaw sensitivity to direct activation of protein kinase C by phorbol 12,13-dibutyrate was enhanced. Compared with unfrozen tissues (pD2 = 7.36 +/- 0.07, n = 32) maximal sensitization to phorbol 12,13-dibutyrate was observed in IMA that had been frozen after 60 minutes of equilibration with the cryomedium (pD2 = 8.31 +/- 0.09, n = 30). Responses to phorbol 12,13-dibutyrate of cryopreserved IMA were highly susceptible to blockade of calcium influx by nifedipine, whereas those of unfrozen IMA were resistant to nifedipine. Against noradrenaline nifedipine was equipotent in cryopreserved (pD'2 = 7.75 +/- 0.15, n = 8) and unfrozen IMA (pD'2 = 7.70 +/- 0.10, n = 6). Endothelium-dependent relaxant responses to acetylcholine were significantly attenuated after cryopreservation (Emax = 26% +/- 5%, n = 4) compared with unfrozen IMA (Emax = 71% +/- 4%, n = 4, p < 0.001); endothelium-independent relaxant responses to sodium nitroprusside were unchanged. CONCLUSIONS Cryopreservation of human IMA under the conditions applied in this study (1) attenuated endothelial cell function and (2) induced an activation of protein kinase C, thereby increasing calcium influx through dihydropyridine-sensitive calcium channels. These experimental data suggest that postoperative administration of calcium channel blockers alone or combined with long-acting nitrates should effectively prevent the development of spasms in arterial grafts.
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Affiliation(s)
- E Müller-Schweinitzer
- Department of Internal Medicine, Kantonsspital, University Hospital Basel, Switzerland
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