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Inhibition of plasminogen activation by albumin may causes impaired fibrinolysis
Poster session abstracts / Atherosclerosis 115 (SuppL ) (1995) $45-S129 PI4 Haemostasis
PI4
S103
HAEMOSTASIS
384
386
I N H I B I T I O N O F P L A S M I N O G E N A C T I V A T I O N BY A L B U M I N M A Y C A U S E S I M P A I R E D FIBRINOLYSIS. M . G . M . de Sain-van der Velden H . A . M . Voorbij, H.J.M. van Rijn Department of Clinical Chemistry, University Hospital Utrecht, The Netherlands
FISH OILS AND THE FIBRINOLYTIC SYSTEM J.M. Silva 1, Souza ~. P. Pimenta, A. Palmeiro#, M. Lourenqo#, C. Ferrer-Amunes#, P. S. Silva, F. Teixeira* 2nd Dept. of Int. Med. of Univ. Hosp., #Haematd. Lab. of Univ. Hosp., *Inst. Phannacol. and Experimental Therapeutics of Faculty of Med., Coimbra, Portugal, and ~Federal Univ. of Pemambuco, Brazil
Fibrinolysis is the process of enzymatic degradation of fibrin clots. Plasmin is the sole enzyme responsible for this process. Plasmin circulates in blood in its zymogen form, plasminogen and is converted to plasmin by tissue plasminogen acivator (t-PA). The enhancement of the fibrinolytic activity of t-PA is due to the formation of a ternary complex with fibrin(ogen) (stimulator) and plasminogen. Since low albumin levels may modulate fibrinolysis, the in vitro plasminogen activation was studied in the presence and absence of commercially obtained albumin. Three stimulators were tested: fibrinogen, a soluble preparation of des AA-fibrinogen and a C N B r digested fibrinogen in combination of three different brands of albumin. A chromogenic substrate highly selective for plasmin was used to detect the generation of plasmin. The plasmin formation was monitored by continuous measurement of the absorbance at 405 n m Control experiments were performed to show that albumin itself had no t-PA, plasmin or plasminogen like activity. This study showed that the plasmin formation was inhibited in the presence of albumin in a dose dependent way, and that the percentage of inhibition was brand dependent. The three different stimulators gave comparable results. In conclusion, these in vitro results suggest that albumin itself may hinder the formation of the ternary complex and thereby interfere in the fibrinolytic process. This may have consequences for patients with a nephrotic syndrome, who have low albumin levels.
We investigated the effect of fish oils (FO) on the fibrinolytic system in Portuguese patients, usually high consumers of fish, olive oil and red wine, with hypertriglyceridaemia and mixed hyperlipidaemla Thirty-six patients participated in this doubleblind study, which consisted of a 4week dietary or wash-out baseline period after which patients were randomly assigned to receive either 12 FO capsules (3.6g/day of omega 3) or similar 12 soya oil (SO) capsules per day for two months. Compliance was assessed by pill count. Patients consumed a mean of 48 meals with fish per week. 44% of the patients were teetotallers. We measured tissue-type plasminogen activator (t-PA) (ng/mL), plasminogen (P) (%), plasminogen activator inhibitor 1 (PALl) (ng/mL), and alpha2-antiplasmin (c~2-ap) (%). The results are shown as mean _.+ SEM. We used paired t test, 2 tail. Soya Oil Fish Oils baseline after % p baseline after % t-PA 15_+1.4 17_+1.8 12.9 16_+1.8 17_+1.8 P 129+4.8 129_+3.3 123+3.0 116-t-3.2 5.7 PAl-1 117-+13.9 96-+5.8 18 140+16.7 117+13.1 16.4 a2-ap 105-+3.2 91_+1.8 13 .004 107_+2.4 88_+1.8 17.8
p .083 .054 .0001
The triglyceride lowering effect of FO (other poster in this congress) didn't show any significant correlations with the changes in the fibrinolytic system. These findings suggest that a high daily dose of FO beneficially influences the fibrinolytic system in hypertriglyceridaemic and mixed hyperlipidaemic patients. SO may have a similar pattern of action. Supported by a grant of Hebron, Caruaru, Brazil
385
387
CLINICAL AND LABORATORY CORRELATIONS OF THE FIBRINOLYTIC SYSTEM IN HYPERTRIGLYCERIDEMIC PATIENTS J.M. Silva. I. Souza t, M. Ascen~:~o, M. Louren~:o 2, C. Ferrer-Antunes -~, P. S. Silva, F. Teixeira 3 2nd Dept of lnt Med of Univ Hosp, 2Haematol Lab of Univ Hosp, 31nst Pharmacol and Experimental Therapeutics of Faculty of Med, Coimbra, Portugal, ~Federal Univ of Pernambuco, Brazil
PERSISTENT PLATELET ACCUMULATION OF EICOSAPENTAENOIC ACID AND DOCOSAHEXAENOIC ACID FOLLOWING WITHDRAWAL OF A SHORT-COURSE SUPPLEMENTATION OF N-3 FATTY ACIDS ETHYL ESTERS. ASSOCIATION WITH IMPAIRMENT OF THE AGGREGATION G. Di Mirmo E. Tremoli, F. Cirillo, G. Vecchione, A. Coppola, A.M. Cerbone, V. De Stefano, D. Colaizzo, P. Rise, C. Galli, and M. Mancini Clinica Medica, lnstituto di Medicina lntema e Malattie Dismetaboliche, Universita' degli Studi di Napoli, Via S. Pansini 5, 80131, lstituto di Scienze Farmacologiche, Universita' degli Studi di Milano, Via Balzareni 9, 20137, Unita' di Trombosi e Aterosclerosi, [R.C.C.S. "Casa Sollievo della Sofferenza" S. Giovanni Rotondo, Italy
We investigated the correlations (r) of the fibrinolytic system in 34 portuguese patients with hypertriglyceridaemia and mixed hyperlipidaemia. The clinical and laboratory study was done after a 4 week dietary or wash-out period. Patients consumed fish 4.8 times per week, 44% were teetotallers, the remaining consuming a mean 449 of alcohol per day, 20% were diabetics, 65% were hypertensives. We measured plasminogen (P) (%), tissue-type plasminogen activator (t-PA) (ng/mL), plasminogen activator inhibitor 1 (PAl-l) (ng/mL), and alpha2-antiplasmin (a2-ap) (%). Fish consumption correlated with t-PA (r=.38, p=.035), a2-ap (r=.368, p=.049), and P (r=-.343, p=.069). BMI correlated with PAI-I (r=.54, p=.002), systolic blood pressure (BP) with P (r=.358, p=.048), and diastolic BP with PAl-1 (r=.396, p=.03), a2-ap (r= .409, p=.03), and P (r=.459, p=.009). Age had no significant r. There weren't differences between teetotallers and drinkers, but among drinkers P has a high r with alcohol consumption (r=0.764, p=0.004). Although there weren't significant r with blood glucose, and any significant differences between non-diabetics and diabetics, diabetics had higher PALl levels (115 vs 139). Total cholesterol, HDL-C, and LDLC correlated with P (respectively r=.342, p=.059; r=-A74, p.008; and r=.648, p=.0001). Triglycerides correlated with PAI-I (r=.385, p=.043). These findings suggest a duplicity in the association of classical atherosclerosis risk factors with the fibrinolytic system in hypertriglyceridaemic and mixed hyperlipidaemic patients.
The duration of the effect on platelet lipid composition and aggregation of a I-mo twice-dally supplementation of 2.28g of fatty acids ethyl esters (FA) was investigated in 14 healthy volunteers. The preparation employed contained cicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in a ratio of 0.9. A marked rise (p<0.05) in the content of both FA and minimal changes in that of arachidonic acid (AA) were documented at the withdrawal of the supplementation. EPA/AA and DHA/AA ratios in phospbolipids revealed that the accumulation persisted 8-12 wks after stopping the supplementation (p<0.05). Platelet aggregation in response to collagen (p<0.05) and ADP was impaired at the withdrawal. The impairment lasted 8-12 wks, and was associated with normal binding of fibrinogen, yon Willebrand factor and prostaglandin El, normal ATP secretion, and normal thromboxane B2 and cAMP formation. Defective (p<0.01) response to collagen and ADP was also observed when normal washed platelets were incubated in in vitro with albumin enriched in EPA and/or DHA. Under these conditions, sensitivity to the thromboxane Ajprostaglandin H 2 mimetic U-46619 was defective as well (p<0.05). These results show a long-lasting impaired platelet aggregation after stopping a relatively short-course supplementation of moderate amounts of FA ethyl esters, and its association with a persistent platelet EA accumulation. They suggest that the impairment may involve inhibition of thromboxane Ajprostaglandin H, receptor by EPA and/or DHA-sensitive mechanisms.
PI4
S103
HAEMOSTASIS
384
386
I N H I B I T I O N O F P L A S M I N O G E N A C T I V A T I O N BY A L B U M I N M A Y C A U S E S I M P A I R E D FIBRINOLYSIS. M . G . M . de Sain-van der Velden H . A . M . Voorbij, H.J.M. van Rijn Department of Clinical Chemistry, University Hospital Utrecht, The Netherlands
FISH OILS AND THE FIBRINOLYTIC SYSTEM J.M. Silva 1, Souza ~. P. Pimenta, A. Palmeiro#, M. Lourenqo#, C. Ferrer-Amunes#, P. S. Silva, F. Teixeira* 2nd Dept. of Int. Med. of Univ. Hosp., #Haematd. Lab. of Univ. Hosp., *Inst. Phannacol. and Experimental Therapeutics of Faculty of Med., Coimbra, Portugal, and ~Federal Univ. of Pemambuco, Brazil
Fibrinolysis is the process of enzymatic degradation of fibrin clots. Plasmin is the sole enzyme responsible for this process. Plasmin circulates in blood in its zymogen form, plasminogen and is converted to plasmin by tissue plasminogen acivator (t-PA). The enhancement of the fibrinolytic activity of t-PA is due to the formation of a ternary complex with fibrin(ogen) (stimulator) and plasminogen. Since low albumin levels may modulate fibrinolysis, the in vitro plasminogen activation was studied in the presence and absence of commercially obtained albumin. Three stimulators were tested: fibrinogen, a soluble preparation of des AA-fibrinogen and a C N B r digested fibrinogen in combination of three different brands of albumin. A chromogenic substrate highly selective for plasmin was used to detect the generation of plasmin. The plasmin formation was monitored by continuous measurement of the absorbance at 405 n m Control experiments were performed to show that albumin itself had no t-PA, plasmin or plasminogen like activity. This study showed that the plasmin formation was inhibited in the presence of albumin in a dose dependent way, and that the percentage of inhibition was brand dependent. The three different stimulators gave comparable results. In conclusion, these in vitro results suggest that albumin itself may hinder the formation of the ternary complex and thereby interfere in the fibrinolytic process. This may have consequences for patients with a nephrotic syndrome, who have low albumin levels.
We investigated the effect of fish oils (FO) on the fibrinolytic system in Portuguese patients, usually high consumers of fish, olive oil and red wine, with hypertriglyceridaemia and mixed hyperlipidaemla Thirty-six patients participated in this doubleblind study, which consisted of a 4week dietary or wash-out baseline period after which patients were randomly assigned to receive either 12 FO capsules (3.6g/day of omega 3) or similar 12 soya oil (SO) capsules per day for two months. Compliance was assessed by pill count. Patients consumed a mean of 48 meals with fish per week. 44% of the patients were teetotallers. We measured tissue-type plasminogen activator (t-PA) (ng/mL), plasminogen (P) (%), plasminogen activator inhibitor 1 (PALl) (ng/mL), and alpha2-antiplasmin (c~2-ap) (%). The results are shown as mean _.+ SEM. We used paired t test, 2 tail. Soya Oil Fish Oils baseline after % p baseline after % t-PA 15_+1.4 17_+1.8 12.9 16_+1.8 17_+1.8 P 129+4.8 129_+3.3 123+3.0 116-t-3.2 5.7 PAl-1 117-+13.9 96-+5.8 18 140+16.7 117+13.1 16.4 a2-ap 105-+3.2 91_+1.8 13 .004 107_+2.4 88_+1.8 17.8
p .083 .054 .0001
The triglyceride lowering effect of FO (other poster in this congress) didn't show any significant correlations with the changes in the fibrinolytic system. These findings suggest that a high daily dose of FO beneficially influences the fibrinolytic system in hypertriglyceridaemic and mixed hyperlipidaemic patients. SO may have a similar pattern of action. Supported by a grant of Hebron, Caruaru, Brazil
385
387
CLINICAL AND LABORATORY CORRELATIONS OF THE FIBRINOLYTIC SYSTEM IN HYPERTRIGLYCERIDEMIC PATIENTS J.M. Silva. I. Souza t, M. Ascen~:~o, M. Louren~:o 2, C. Ferrer-Antunes -~, P. S. Silva, F. Teixeira 3 2nd Dept of lnt Med of Univ Hosp, 2Haematol Lab of Univ Hosp, 31nst Pharmacol and Experimental Therapeutics of Faculty of Med, Coimbra, Portugal, ~Federal Univ of Pernambuco, Brazil
PERSISTENT PLATELET ACCUMULATION OF EICOSAPENTAENOIC ACID AND DOCOSAHEXAENOIC ACID FOLLOWING WITHDRAWAL OF A SHORT-COURSE SUPPLEMENTATION OF N-3 FATTY ACIDS ETHYL ESTERS. ASSOCIATION WITH IMPAIRMENT OF THE AGGREGATION G. Di Mirmo E. Tremoli, F. Cirillo, G. Vecchione, A. Coppola, A.M. Cerbone, V. De Stefano, D. Colaizzo, P. Rise, C. Galli, and M. Mancini Clinica Medica, lnstituto di Medicina lntema e Malattie Dismetaboliche, Universita' degli Studi di Napoli, Via S. Pansini 5, 80131, lstituto di Scienze Farmacologiche, Universita' degli Studi di Milano, Via Balzareni 9, 20137, Unita' di Trombosi e Aterosclerosi, [R.C.C.S. "Casa Sollievo della Sofferenza" S. Giovanni Rotondo, Italy
We investigated the correlations (r) of the fibrinolytic system in 34 portuguese patients with hypertriglyceridaemia and mixed hyperlipidaemia. The clinical and laboratory study was done after a 4 week dietary or wash-out period. Patients consumed fish 4.8 times per week, 44% were teetotallers, the remaining consuming a mean 449 of alcohol per day, 20% were diabetics, 65% were hypertensives. We measured plasminogen (P) (%), tissue-type plasminogen activator (t-PA) (ng/mL), plasminogen activator inhibitor 1 (PAl-l) (ng/mL), and alpha2-antiplasmin (a2-ap) (%). Fish consumption correlated with t-PA (r=.38, p=.035), a2-ap (r=.368, p=.049), and P (r=-.343, p=.069). BMI correlated with PAI-I (r=.54, p=.002), systolic blood pressure (BP) with P (r=.358, p=.048), and diastolic BP with PAl-1 (r=.396, p=.03), a2-ap (r= .409, p=.03), and P (r=.459, p=.009). Age had no significant r. There weren't differences between teetotallers and drinkers, but among drinkers P has a high r with alcohol consumption (r=0.764, p=0.004). Although there weren't significant r with blood glucose, and any significant differences between non-diabetics and diabetics, diabetics had higher PALl levels (115 vs 139). Total cholesterol, HDL-C, and LDLC correlated with P (respectively r=.342, p=.059; r=-A74, p.008; and r=.648, p=.0001). Triglycerides correlated with PAI-I (r=.385, p=.043). These findings suggest a duplicity in the association of classical atherosclerosis risk factors with the fibrinolytic system in hypertriglyceridaemic and mixed hyperlipidaemic patients.
The duration of the effect on platelet lipid composition and aggregation of a I-mo twice-dally supplementation of 2.28g of fatty acids ethyl esters (FA) was investigated in 14 healthy volunteers. The preparation employed contained cicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in a ratio of 0.9. A marked rise (p<0.05) in the content of both FA and minimal changes in that of arachidonic acid (AA) were documented at the withdrawal of the supplementation. EPA/AA and DHA/AA ratios in phospbolipids revealed that the accumulation persisted 8-12 wks after stopping the supplementation (p<0.05). Platelet aggregation in response to collagen (p<0.05) and ADP was impaired at the withdrawal. The impairment lasted 8-12 wks, and was associated with normal binding of fibrinogen, yon Willebrand factor and prostaglandin El, normal ATP secretion, and normal thromboxane B2 and cAMP formation. Defective (p<0.01) response to collagen and ADP was also observed when normal washed platelets were incubated in in vitro with albumin enriched in EPA and/or DHA. Under these conditions, sensitivity to the thromboxane Ajprostaglandin H 2 mimetic U-46619 was defective as well (p<0.05). These results show a long-lasting impaired platelet aggregation after stopping a relatively short-course supplementation of moderate amounts of FA ethyl esters, and its association with a persistent platelet EA accumulation. They suggest that the impairment may involve inhibition of thromboxane Ajprostaglandin H, receptor by EPA and/or DHA-sensitive mechanisms.