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Polymorphisms of the plasminogen activator inhibitor-1 gene in type 1 and type 2 diabetes, with and without vascular complications
86
237
ORAL COMMUNICATATIONS H-7: Fibrinolysis
In Vascular Disease
POLYMORPHISMS OF THE PLASMINOGEN ACTIVATOR INHIBITOR-1 GENE IN TYPE 1 AND TYPE 2 DIABETES, WITH AND WITHOUT VASCULAR COMPLICATIONS. Mansfield MW, Stickland MH. Carter AM, Grant PJ. Diabetes an! Thrombosis Research Group, Division of Medicine, The General Infirmary at Leeds, Leeds. LSI 3EX. United Kingdom. Circulating levels of plasminogen activator inhibitor-l (PAI1) are high in type 2 diabetes and low or normal in type 1 diabetes. There is evidence from studies in non-diabetic subjects that circulating levels of PAI- are partly genetically determined. These findings may be important with respect to the development of the vascular complications of diabetes as suppressed fibrinolysis due to high levels of PAI- have been related to both coronary artery and retinal vessel disease. To identify whether genotype contributes 10 the difference in PAI-I levels in type 1 and type 2 diabetic subjects and whether genotype relates to the development of retinopathy and peripheral vascular disease (PVD), a Hind Ill restriction fragment length polymorphism (RFLP) and a dinucleotide repeat polymorphism at the PAI-I gene were studied. In 519 Caucasian diabetic subjects (192 type
238 LOCALISATION
AND QUANTIFICATION OF PROTEINS OF THE FJBRINOLYTIC SYSTEM IN NORMAL AND ATHEROSCLEROTIC VESSELS. *Linda A Robbie 2Nuala A Booth, 3Paul A J Brown, Departments of ‘Alison M Croll ‘and IBruce Bennett ‘Medicine & Therapeutics, 2Molecul& & Cell Biology and 3Pathology, University of Aberdeen, Scotland, UK.
Impaired fibrinolysis, within or at the surface of the vessel wall, may play a significant role in the development of atherosclerotic lesions and contribute to thrombus formation. This study examines the activators and inhibitors of the fibrinolytic system in normal and diseased blood vessel walls. Specimens of aorta were obtained at autopsy and stained using the APAAP technique. Extracts were prepared for quantitative immunoassay. Highly positive staining for plasminogen activator inhibitor 1 (PAI-I) was present in arteries with lesions especially in the areas surrounding the plaque itself. In normal vessels staining for PAI- was less intense and was more evenly distributed throughout the layers of the vessel. These data correlated well with the
239 INFLUENCE OF CONTINUOUS INFUSION OF PROSTACYCLIN ON PLASMA LEVELS OF t-PA, PAIAND vWF IN PRIMARY PULMONARY HYPERTENSION ‘Rove Neumann c, 2Brenot F. ‘Wolf M, 2.SimonneaG, 2Duro:; P, 1v3Mever D and 3Anal&-CanQ E. ‘Service d’Hematolo;ie et *Service de Pneumologie, Hbpital A. B&cl&e, Clamart, and 3lNSERM U. 143, HBpital de Bic&re, Paris, France. Primary pulmonary hypertension (PPH) is a severe disease characterized by chronic microvascular injury in which thrombosis of small pulmonary arteries may play a major role. Clinical status and survival in patients with PPH selected for lung transplantation are improved by long-term continuous infusion of prostacyclin (epoprostenol; Flolano, Wellcome); its precise mechanism of action remains, however, unclear. Since prostacyclin has direct effects on the vascular wall and endothelial markers of fibrinolysis (t-PA, PAI-1) and von Willebrand factor (vWF) are abnormally increased in PPH, we determined the plasma levels of these proteins before and during prostacyclin infusion in 15 patients (14 females, 1 male; mean age 36 years) with severe PPH (mean pulmonary artery
1, 327 type 2) and 123 Caucasian control subjects there were no differences in the frequency of the Hind Ill RFLP alleles (type 1 vs type 2 vs control: allele 1 0.40 vs 0.42 vs 0.45, allele 2 0.60 vs 0.48 vs 0.55) nor in the allelic frequencies at the dinucleotide repeat sequence. In 86 subjects with no retinopathy at 15 years or more from diagnosis of diabetes and 190 subjects with diabetic retinopathy there was no difference in the frequency of Hind Ill RFLP alleles (retinopathy absent vs retinopathy present: allele 1 0.40 vs 0.47, allele 2 0.60 vs 0.53) nor in the allelic frequencies at the dinucleotide repeat sequence. In 67 type 2 diabetic patients with PVD, 93 type 2 diabetic controls and 123 healthy controls, there was no difference in allele frequencies at either site. (PAI- Hind Ill: PVD v diabetic control v healthy control, allele 1; 0.50 v 0.42 v 0.45 , allele 2; 0.50 v 0.58 v 0.55) The results indicate that there is no or minimal influence of the PAI- gene on either PAI- levels or the development of diabetic retinopathy or peripheral vascular disease in patients with diabetes mellitus.
corresponding antigen levels in the extracts, PAIconcentrations being significantly higher in arteries with atherosclerotic lesions. Extracts prepared from the individual layers of the vessels confirmed the presence of high levels of PAI- in the intima and media of diseased vessels compared with the adventitia. The distribution of vitronectin, known for its ability to stabilise PAIactivity, was comparable to that of PAI- in these lesions. orz-antiplasmin ((YzAP) was present at high levels in both normal and atherosclerotic vessels but significantly higher levels were detected in several lesions with plaque. Positive staining for CXZ-AP was visible around the plaque. Staining for hssue plaminogen activator (t-PA) was localised around the plaque but t-PA levels were lower in diseased vessels. Urokinase (u-PA) demonstrated striking positivity in diseased vessels compared with normal vessels. In atherosclerotic vessels high levels of PAI- and a~-AP together with lower levels of t-PA, may contribute to the development and persistence of adjacent thrombi.
82 f 12 mm Hg, cardiac index: 1.9 I!I 0.3 L/min/m2). A first group of patients, n = 8, was studied before (day 0) and at day 8 of prostacyclin infusion. A second group (n = 7) was studied daily from day 0 to day 10 + 2. Patients had either increased PAI- (>40 ng/ml, n = 5) or t-PA (>lO ng/ml, n = 6) or both (n = 3); most patients had increased vWF (~150 %, n = 13). The concentration of t-PA or PAI- decreased with the infusion of prostacylin in a biphasic fashion: the first phase was characterized by a rapid decrease (50 % at day 2) and was followed by a slow phase lasting from day 2 to day 8 (additional decrease to 65%). Although in 4 patients the initial concentration of PAI- (21-23 ng/ml) was within the normal range (lo-40 ng/ml), a similar profile was observed with the infusion of prostacyclin. Plasma levels of vWF only showed a discrete trend towards lower values. These results indicate that prostacyclin infusion influences either the clearance or the synthesis/release of endothelial t-PA and PAI-1. Thus, parameters that indicate endothelial injury are positively modified during prostacylin infusion and become normal. This normalisation parallels the clinical improvement observed in these patients, but no direct cause effect relationship can be drawn from these studies. pressure:
237
ORAL COMMUNICATATIONS H-7: Fibrinolysis
In Vascular Disease
POLYMORPHISMS OF THE PLASMINOGEN ACTIVATOR INHIBITOR-1 GENE IN TYPE 1 AND TYPE 2 DIABETES, WITH AND WITHOUT VASCULAR COMPLICATIONS. Mansfield MW, Stickland MH. Carter AM, Grant PJ. Diabetes an! Thrombosis Research Group, Division of Medicine, The General Infirmary at Leeds, Leeds. LSI 3EX. United Kingdom. Circulating levels of plasminogen activator inhibitor-l (PAI1) are high in type 2 diabetes and low or normal in type 1 diabetes. There is evidence from studies in non-diabetic subjects that circulating levels of PAI- are partly genetically determined. These findings may be important with respect to the development of the vascular complications of diabetes as suppressed fibrinolysis due to high levels of PAI- have been related to both coronary artery and retinal vessel disease. To identify whether genotype contributes 10 the difference in PAI-I levels in type 1 and type 2 diabetic subjects and whether genotype relates to the development of retinopathy and peripheral vascular disease (PVD), a Hind Ill restriction fragment length polymorphism (RFLP) and a dinucleotide repeat polymorphism at the PAI-I gene were studied. In 519 Caucasian diabetic subjects (192 type
238 LOCALISATION
AND QUANTIFICATION OF PROTEINS OF THE FJBRINOLYTIC SYSTEM IN NORMAL AND ATHEROSCLEROTIC VESSELS. *Linda A Robbie 2Nuala A Booth, 3Paul A J Brown, Departments of ‘Alison M Croll ‘and IBruce Bennett ‘Medicine & Therapeutics, 2Molecul& & Cell Biology and 3Pathology, University of Aberdeen, Scotland, UK.
Impaired fibrinolysis, within or at the surface of the vessel wall, may play a significant role in the development of atherosclerotic lesions and contribute to thrombus formation. This study examines the activators and inhibitors of the fibrinolytic system in normal and diseased blood vessel walls. Specimens of aorta were obtained at autopsy and stained using the APAAP technique. Extracts were prepared for quantitative immunoassay. Highly positive staining for plasminogen activator inhibitor 1 (PAI-I) was present in arteries with lesions especially in the areas surrounding the plaque itself. In normal vessels staining for PAI- was less intense and was more evenly distributed throughout the layers of the vessel. These data correlated well with the
239 INFLUENCE OF CONTINUOUS INFUSION OF PROSTACYCLIN ON PLASMA LEVELS OF t-PA, PAIAND vWF IN PRIMARY PULMONARY HYPERTENSION ‘Rove Neumann c, 2Brenot F. ‘Wolf M, 2.SimonneaG, 2Duro:; P, 1v3Mever D and 3Anal&-CanQ E. ‘Service d’Hematolo;ie et *Service de Pneumologie, Hbpital A. B&cl&e, Clamart, and 3lNSERM U. 143, HBpital de Bic&re, Paris, France. Primary pulmonary hypertension (PPH) is a severe disease characterized by chronic microvascular injury in which thrombosis of small pulmonary arteries may play a major role. Clinical status and survival in patients with PPH selected for lung transplantation are improved by long-term continuous infusion of prostacyclin (epoprostenol; Flolano, Wellcome); its precise mechanism of action remains, however, unclear. Since prostacyclin has direct effects on the vascular wall and endothelial markers of fibrinolysis (t-PA, PAI-1) and von Willebrand factor (vWF) are abnormally increased in PPH, we determined the plasma levels of these proteins before and during prostacyclin infusion in 15 patients (14 females, 1 male; mean age 36 years) with severe PPH (mean pulmonary artery
1, 327 type 2) and 123 Caucasian control subjects there were no differences in the frequency of the Hind Ill RFLP alleles (type 1 vs type 2 vs control: allele 1 0.40 vs 0.42 vs 0.45, allele 2 0.60 vs 0.48 vs 0.55) nor in the allelic frequencies at the dinucleotide repeat sequence. In 86 subjects with no retinopathy at 15 years or more from diagnosis of diabetes and 190 subjects with diabetic retinopathy there was no difference in the frequency of Hind Ill RFLP alleles (retinopathy absent vs retinopathy present: allele 1 0.40 vs 0.47, allele 2 0.60 vs 0.53) nor in the allelic frequencies at the dinucleotide repeat sequence. In 67 type 2 diabetic patients with PVD, 93 type 2 diabetic controls and 123 healthy controls, there was no difference in allele frequencies at either site. (PAI- Hind Ill: PVD v diabetic control v healthy control, allele 1; 0.50 v 0.42 v 0.45 , allele 2; 0.50 v 0.58 v 0.55) The results indicate that there is no or minimal influence of the PAI- gene on either PAI- levels or the development of diabetic retinopathy or peripheral vascular disease in patients with diabetes mellitus.
corresponding antigen levels in the extracts, PAIconcentrations being significantly higher in arteries with atherosclerotic lesions. Extracts prepared from the individual layers of the vessels confirmed the presence of high levels of PAI- in the intima and media of diseased vessels compared with the adventitia. The distribution of vitronectin, known for its ability to stabilise PAIactivity, was comparable to that of PAI- in these lesions. orz-antiplasmin ((YzAP) was present at high levels in both normal and atherosclerotic vessels but significantly higher levels were detected in several lesions with plaque. Positive staining for CXZ-AP was visible around the plaque. Staining for hssue plaminogen activator (t-PA) was localised around the plaque but t-PA levels were lower in diseased vessels. Urokinase (u-PA) demonstrated striking positivity in diseased vessels compared with normal vessels. In atherosclerotic vessels high levels of PAI- and a~-AP together with lower levels of t-PA, may contribute to the development and persistence of adjacent thrombi.
82 f 12 mm Hg, cardiac index: 1.9 I!I 0.3 L/min/m2). A first group of patients, n = 8, was studied before (day 0) and at day 8 of prostacyclin infusion. A second group (n = 7) was studied daily from day 0 to day 10 + 2. Patients had either increased PAI- (>40 ng/ml, n = 5) or t-PA (>lO ng/ml, n = 6) or both (n = 3); most patients had increased vWF (~150 %, n = 13). The concentration of t-PA or PAI- decreased with the infusion of prostacylin in a biphasic fashion: the first phase was characterized by a rapid decrease (50 % at day 2) and was followed by a slow phase lasting from day 2 to day 8 (additional decrease to 65%). Although in 4 patients the initial concentration of PAI- (21-23 ng/ml) was within the normal range (lo-40 ng/ml), a similar profile was observed with the infusion of prostacyclin. Plasma levels of vWF only showed a discrete trend towards lower values. These results indicate that prostacyclin infusion influences either the clearance or the synthesis/release of endothelial t-PA and PAI-1. Thus, parameters that indicate endothelial injury are positively modified during prostacylin infusion and become normal. This normalisation parallels the clinical improvement observed in these patients, but no direct cause effect relationship can be drawn from these studies. pressure: