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The additive effect of dermatan sulfate and low molecular weight heparins on thrombin inhibition in vitro
ABSTRACTS OF 12TH INTNAT’L CONGRESS
Vol. 65, Suppi. 1
P330 A NEW LMW DERMATAN SULFATE (DESMJN). EFFECTS ON COAGULATION AND FJBRJNOLYSIS C. Legnani, G. Palareti, R. Biagi, S. Ludovici, L. Maggiore’, S. Coccheri Dept. Angiology and Blood Coagulation, S. Orsola Hospital, Bologna, 1 I Opocrin S.p.A., Corlo (MO), J A new LMW Dermatan Sulfate (Desmin, DES) obtained by depolymerizatioa of the native form, extracted from pig duodenal mucosa, with mean m.w. of 5.000 + I .OOOand containing 5 1% of LMW heparin, was administered i.m. to 12 healthy subjects ( 19-26 y, 9 males). Two different doses ( 100 and 200 mg) and placebo (P) were given once daily for 7 days each, separated by 15 days wash-out intervals. Blood samples were collected before (TO), 2 (T2), 4 (T4), and 6 (T6) hours after the fust administration and on 4th and 8th days. Levels of DES (Stachrom) increased, peaking at T2 (TO: 0.26 k 0.01 &ml, T2: 2.47 + 0.20 for the 200 mg dose), and were still higher than baseline at T6 (T6: 1.2 1 -t 0.07). aPTT and Thrombin T. did not change. An increase in anti-Xa activity was recorded (for 200 mg DES, TO: 0.052 + 0.003 JUlml, T4: 0. I35 + 0.007) 1evelJing out till the 4th hour and then decreasing. t-PA antigen levels were higher at T2 (p < 0.05) and T4 aRer 200 mg DES. In conclusion, DES has a long bioavailability, and unexpectedly showed anti-Xa activity, not justified by the amount of contaminant LMW heparin; it also moderately increased t-PA antigen.
P331 THE ADDJTJVE EFFECT OF DERMATAN SULFATE AND LOW MOLECULAR WEIGHT HEPARJNS ON THROMBJN INHIBITION IN VITRO B. Cosmi’, J.J. WeitS, G. Agnelli’, J. Hirshl I Jstituto di Semeiotica Medica, Universita di Perugia, Perugia. J and * Hamilton Civic Hospitals Research Centre, Hamilton, Ontario, CDN The aim of this study was to investigate the mechanism of the potentiation of the anticoagulant activity of dermatan sulfate (DS) by low molecular weight heparins (LMWHs) in vitro. LMWHs (0.5 and 0.8 pg/mJ ofboth Fragmin and Enoxaparine) increased the effect of DS (2, 5, 10 &ml of MF-701, Mediolanum Farmaceutici, Milan, I) on thrombin (Ha) inhibition in platelet poor plasma (PPP) as measured with a chromogenic substrate assay.An additive effect was indicated when the interaction was analyzed with the method of Berenbaum. The additive effect observed in PPP was lost when the experiments with the same combination of compounds were repeated in antithrombin IJJ (ATJJI) depleted plasma. ARer the addition of *2sl-Jla to PPP, autoradiographies showed an increase of Ha-heparin cofactor II (HCJJ) complexes in the presence of DS, when compared to PPP in the absence of DS. In the presence of DS and JMWH, an increase in JJa-ATIJJ complexes was observed, while the JJa-HCJI complexes were virtually unchanged, when compared to DS alone. These findings indicate that the two glycosaminoglycans can concomitantly inhibit thrombin by two separate pathways: DS by potentiating HCIJ and LMWH by potentiating ATJJI. These data support the potential use of small doses of LMWH in vivo to potentiate the effect of dermatan sulfate.
Vol. 65, Suppi. 1
P330 A NEW LMW DERMATAN SULFATE (DESMJN). EFFECTS ON COAGULATION AND FJBRJNOLYSIS C. Legnani, G. Palareti, R. Biagi, S. Ludovici, L. Maggiore’, S. Coccheri Dept. Angiology and Blood Coagulation, S. Orsola Hospital, Bologna, 1 I Opocrin S.p.A., Corlo (MO), J A new LMW Dermatan Sulfate (Desmin, DES) obtained by depolymerizatioa of the native form, extracted from pig duodenal mucosa, with mean m.w. of 5.000 + I .OOOand containing 5 1% of LMW heparin, was administered i.m. to 12 healthy subjects ( 19-26 y, 9 males). Two different doses ( 100 and 200 mg) and placebo (P) were given once daily for 7 days each, separated by 15 days wash-out intervals. Blood samples were collected before (TO), 2 (T2), 4 (T4), and 6 (T6) hours after the fust administration and on 4th and 8th days. Levels of DES (Stachrom) increased, peaking at T2 (TO: 0.26 k 0.01 &ml, T2: 2.47 + 0.20 for the 200 mg dose), and were still higher than baseline at T6 (T6: 1.2 1 -t 0.07). aPTT and Thrombin T. did not change. An increase in anti-Xa activity was recorded (for 200 mg DES, TO: 0.052 + 0.003 JUlml, T4: 0. I35 + 0.007) 1evelJing out till the 4th hour and then decreasing. t-PA antigen levels were higher at T2 (p < 0.05) and T4 aRer 200 mg DES. In conclusion, DES has a long bioavailability, and unexpectedly showed anti-Xa activity, not justified by the amount of contaminant LMW heparin; it also moderately increased t-PA antigen.
P331 THE ADDJTJVE EFFECT OF DERMATAN SULFATE AND LOW MOLECULAR WEIGHT HEPARJNS ON THROMBJN INHIBITION IN VITRO B. Cosmi’, J.J. WeitS, G. Agnelli’, J. Hirshl I Jstituto di Semeiotica Medica, Universita di Perugia, Perugia. J and * Hamilton Civic Hospitals Research Centre, Hamilton, Ontario, CDN The aim of this study was to investigate the mechanism of the potentiation of the anticoagulant activity of dermatan sulfate (DS) by low molecular weight heparins (LMWHs) in vitro. LMWHs (0.5 and 0.8 pg/mJ ofboth Fragmin and Enoxaparine) increased the effect of DS (2, 5, 10 &ml of MF-701, Mediolanum Farmaceutici, Milan, I) on thrombin (Ha) inhibition in platelet poor plasma (PPP) as measured with a chromogenic substrate assay.An additive effect was indicated when the interaction was analyzed with the method of Berenbaum. The additive effect observed in PPP was lost when the experiments with the same combination of compounds were repeated in antithrombin IJJ (ATJJI) depleted plasma. ARer the addition of *2sl-Jla to PPP, autoradiographies showed an increase of Ha-heparin cofactor II (HCJJ) complexes in the presence of DS, when compared to PPP in the absence of DS. In the presence of DS and JMWH, an increase in JJa-ATIJJ complexes was observed, while the JJa-HCJI complexes were virtually unchanged, when compared to DS alone. These findings indicate that the two glycosaminoglycans can concomitantly inhibit thrombin by two separate pathways: DS by potentiating HCIJ and LMWH by potentiating ATJJI. These data support the potential use of small doses of LMWH in vivo to potentiate the effect of dermatan sulfate.