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Capillary rarefaction and hypertension-induced endorgan damage
330
XVII S.I.S.A. National Congress
CAPZLLARY R A R E F A C T I O N AND H Y P E R T E N S I O N - I N D U C E D ORGAN DAMAGE Ciuffetti G, L o m b a r d i n i R, I n n o c e n t e N o t a r i s t e f a n o S, Schillaci G, M a n n a r i n o E.
S,
END-
Pasqualini
L,
Medicina Interna, Angiologia e Malattie da Artariosclrosi. Perugia, Italia Objective: to determine the effects of capillary rarefaction on vascular reactivity and microcirculatory functioning in essential hypertension. Background: hypertension is associated with abnormal vascular reactivity and increased vasoconstriction. Capillary rarefaction amplifies these abnormalities, which modify microcirculatory hemodynamics. Methods: sixty-one men with never-treated essential hypertension and capillary rarefaction (<80 capillaries per field) and 20 age- and sexmatched controls, underwent a strenuous cycle ergometer test to monitor, during exercise and recovery, the blood pressure profile and the haemorheological pattern: blood viscosity at low shear, haematecrit and leucocyte count, P-selectin levels and red and white blood cell filterability rates. The veno-arteriolar reflex was determined by laserDoppler flowmetry before exercise and at recovery. Results: hypertensive men with < 72 capillaries per field had an abnormal haemorheological profile before exercise. The physiological response to exercise was observed only in the controls and hypertensives with > 73 capillaries per field. Abnormal responses to exercise worsened as capillaries were more rarefied. At recovery, haemorheological parameters in hypertensives with 65-72 capillaries per field returned to baseline, remaining significantly (p<0.05) different to control values. Variations in the haemorheological pattern in hypertensives with <64 capillary per field persisted. The veno-arteriolar reflex followed the same pattern. Conclusion: persistent rheological changes in a reduced microvascular network may contribute to accelerate hypertensionrelated organ damage.
VARIATIONS OF SOME PERIPHERAL MARKERS OF S E R O T O N I N E R G I C SYSTEM I N SELECTED VASCULAR PATIENTS
PLATELETACTIVATING FACTOR ACETYLHYDROLASE ( P A F - A H ) GENE P O L Y M O R P H I S M S A N D ACTZVITY ARE NOT A S S O C I A T E D WITH CAROTID ARTERIAL WALL THICKNESS IN HYPERCHOLESTEROLEMIC SUBJECTS Cristadoro S, Bonaiuto A, Bitto A, Fontana L, Campo S, Bo n a iu to M, Cinquegrani M, Sardo MA, Saitta A Dipartimento di Medicina Interna - Universit~degli Studi di Messina Plasma platelet-activating factor acetylhydrolase (PAF-AH) has been implicated in atherosclerosis and cardiovascular disease (CAD) because its role in the metabolism of bioactive lipids such as oxidized phospholipids and PAF (Platelet-Activating Factor), a potent lipid mediater involved in inflammatory disease. This study was performed to evaluate the contribution of PAF-AH gene polymorhisms Arg92His, Ile198Thr and Ala379Val variants to the presence of carotid atherosclerosis in 190 (99 men and 91 women, mean age 57±10.28 years) Sicilian hypercholestarolemic subjects (HCh). Carotid artery intima-media wall thickness (IP1T) was measured as an indicator of early atherosclerosis disease. The subjects were classified according to have normal < l m m ) or abnormal ( > l m m ) IMT. Subjects were also investigated for physical and biochemical paramenters, including PAFAH activity HCh showed higher values of PAF-AH activity compared with those of a control group (200 healthy subjects matched for sex and age). A significant correlation were observed between PAF-AH activity and LDL, but there was no correlation with HDL values. No significant differences were detected among the PAF-AH gene polymorphisms with respecting to age, sex, BMI, plasma glucose, lipids levels, PAF-AH activity, blood pressure and smoking habit in HCh with normal or abnormal IMT. The analysis of PAF-AH genotypes distribution showed no significant differences in percentage of 92, 198 and 379 genotypes in both IMT groups. In conclusion our data did not provide evidence that PAF-AH polymorphisms influence PAF-AH activity and atherosclerosis in Sicilian hypercholesterolemic patients.
REDUCED FACL4 EXPRESSION IN VULNERABLE ATHEROSCLEROTIC PLAQUES AS A B A S I S FOR PGE2-DEPENDENT PLAQUE I N S T A B I L I T Y
de Lalla A t'2z Blardi P 1,2 , Palazzuoli A 2 Ghezzi A t,2 A u t e r i A t,2 Centro di Farmacologia Clinica ~, Dipartimento di Medicina Clinica e Scienze Immuno]ogiche z Universit~degli Studi di Siena Serotonin (5-HT) is a decarboxylated derivative of trypthophan. Synthesized in enterochromaffin cells, it is released in circulation and incorporated into platelets. At the site of endothelial lesions, platelets aggregate and release 5-HT that presents several actions involved in atherogenesis: vasoconstriction in the presence of endothelial injury, aggregation of platelets, and mitogenesis of arterial muscle cells and endothelial cells. It may also contribute to the vascular inflammation associated with atherosclerosis by increasing the synthesis of Interleukin-6 in vascular muscle cells. If studies in vitro suggest an atherogenic role for 5-HT, a limited number of studies in vivo described a relation between 5-HT and atheroscierosis. We evaluated 5-HT in plasma and platelets of patients with unstable angina and stroke to identify an association between 5-HT and atherosclerosis of coronary and cerebral arteries. Twenty patients (14 men, 6 women, mean age 69±10 years) with unstable angina and 15 patients (7 men, 8 women, mean age 81±10 years) with stroke were included in the study. Twenty-four healthy subjects (10 men, 14 women, mean age 31=1=6 years) constituted the control group. Blood samples were drawn to determine plasma and platelet 5-HT concentrations. Serotonin was determined by HPLC. We observed that 5-HT levels in platelets in patients with unstable angina (105±46 ng/200000 cell) were significantly lower (p
M Fazia 1, A Iezzi 1, B Pinil,C Cuccurullo 1, M Zucchellil, D De Cesare z, S Ucchino z, F SpigonardoZ, M de Luca 1, SM Pre s co tt 2, F CuccurulloZ,A M e z z e t t i z, F Cipollone z 1University of Chieti "G. d'Annunzio", Italy; 2University of Utah, USA Inducible cyclooxygenase (COX-2) and prostaglandin (PG) E synthase (mPGES-1) are up-regulated in unstable plaques, contributing to their vulnerability through PGE2-dependent release of metalloproteinases (MMPs). In addition to COX, arachidonic acid (AA) can be substrate for the fatty acid-CoA rigase (FACL) 4,whose expression could therefore limit PGE2 release. Aim of our study was to evaluate FACL4 expression in plaques and correlate it with inflammatory infiltration and PGE2dependent MMP activity. Plaques were obtained from 60 patients who underwent carotid endarterectomy and divided into 2 groups (Symptomatic and Asymptomatic) according to recent evidence of stroke. Plaques were analyzed for CD68+ macrophages, CD3+ T cells, FACL4, COX-2, mPGES-1, MMP-2 and MMP-9 by immunohistochemistry and western blot; zymography was used to detect MMP activity. Inflammatory area was larger (P<0.O001) in symptomatic plaques. FACL4 staining was lower in symptomatic than in asymptomatic plaques (8+/-3% vs 23+/-5%, P<0.O001), and always associated with higher MMP-2 and MMP-9 expression. All symptomatic plaques contained activated MMPs. In contrast, COX-2 and mPGES-1 expression was higher in vulnerable plaques (P<0.O001). Double immunofluorescence co-localized FACL4 with COX-2, mPGES-1 and MMPs in macrophages. This study provides the first evidence that reduced FACL4 expression in plaque macrophages is associated with acute ischemic syndromes possibly through ineffective removal of unesterified AA, leading to PGE2-induced MMP release and plaque rupture.
XVII S.I.S.A. National Congress
CAPZLLARY R A R E F A C T I O N AND H Y P E R T E N S I O N - I N D U C E D ORGAN DAMAGE Ciuffetti G, L o m b a r d i n i R, I n n o c e n t e N o t a r i s t e f a n o S, Schillaci G, M a n n a r i n o E.
S,
END-
Pasqualini
L,
Medicina Interna, Angiologia e Malattie da Artariosclrosi. Perugia, Italia Objective: to determine the effects of capillary rarefaction on vascular reactivity and microcirculatory functioning in essential hypertension. Background: hypertension is associated with abnormal vascular reactivity and increased vasoconstriction. Capillary rarefaction amplifies these abnormalities, which modify microcirculatory hemodynamics. Methods: sixty-one men with never-treated essential hypertension and capillary rarefaction (<80 capillaries per field) and 20 age- and sexmatched controls, underwent a strenuous cycle ergometer test to monitor, during exercise and recovery, the blood pressure profile and the haemorheological pattern: blood viscosity at low shear, haematecrit and leucocyte count, P-selectin levels and red and white blood cell filterability rates. The veno-arteriolar reflex was determined by laserDoppler flowmetry before exercise and at recovery. Results: hypertensive men with < 72 capillaries per field had an abnormal haemorheological profile before exercise. The physiological response to exercise was observed only in the controls and hypertensives with > 73 capillaries per field. Abnormal responses to exercise worsened as capillaries were more rarefied. At recovery, haemorheological parameters in hypertensives with 65-72 capillaries per field returned to baseline, remaining significantly (p<0.05) different to control values. Variations in the haemorheological pattern in hypertensives with <64 capillary per field persisted. The veno-arteriolar reflex followed the same pattern. Conclusion: persistent rheological changes in a reduced microvascular network may contribute to accelerate hypertensionrelated organ damage.
VARIATIONS OF SOME PERIPHERAL MARKERS OF S E R O T O N I N E R G I C SYSTEM I N SELECTED VASCULAR PATIENTS
PLATELETACTIVATING FACTOR ACETYLHYDROLASE ( P A F - A H ) GENE P O L Y M O R P H I S M S A N D ACTZVITY ARE NOT A S S O C I A T E D WITH CAROTID ARTERIAL WALL THICKNESS IN HYPERCHOLESTEROLEMIC SUBJECTS Cristadoro S, Bonaiuto A, Bitto A, Fontana L, Campo S, Bo n a iu to M, Cinquegrani M, Sardo MA, Saitta A Dipartimento di Medicina Interna - Universit~degli Studi di Messina Plasma platelet-activating factor acetylhydrolase (PAF-AH) has been implicated in atherosclerosis and cardiovascular disease (CAD) because its role in the metabolism of bioactive lipids such as oxidized phospholipids and PAF (Platelet-Activating Factor), a potent lipid mediater involved in inflammatory disease. This study was performed to evaluate the contribution of PAF-AH gene polymorhisms Arg92His, Ile198Thr and Ala379Val variants to the presence of carotid atherosclerosis in 190 (99 men and 91 women, mean age 57±10.28 years) Sicilian hypercholestarolemic subjects (HCh). Carotid artery intima-media wall thickness (IP1T) was measured as an indicator of early atherosclerosis disease. The subjects were classified according to have normal < l m m ) or abnormal ( > l m m ) IMT. Subjects were also investigated for physical and biochemical paramenters, including PAFAH activity HCh showed higher values of PAF-AH activity compared with those of a control group (200 healthy subjects matched for sex and age). A significant correlation were observed between PAF-AH activity and LDL, but there was no correlation with HDL values. No significant differences were detected among the PAF-AH gene polymorphisms with respecting to age, sex, BMI, plasma glucose, lipids levels, PAF-AH activity, blood pressure and smoking habit in HCh with normal or abnormal IMT. The analysis of PAF-AH genotypes distribution showed no significant differences in percentage of 92, 198 and 379 genotypes in both IMT groups. In conclusion our data did not provide evidence that PAF-AH polymorphisms influence PAF-AH activity and atherosclerosis in Sicilian hypercholesterolemic patients.
REDUCED FACL4 EXPRESSION IN VULNERABLE ATHEROSCLEROTIC PLAQUES AS A B A S I S FOR PGE2-DEPENDENT PLAQUE I N S T A B I L I T Y
de Lalla A t'2z Blardi P 1,2 , Palazzuoli A 2 Ghezzi A t,2 A u t e r i A t,2 Centro di Farmacologia Clinica ~, Dipartimento di Medicina Clinica e Scienze Immuno]ogiche z Universit~degli Studi di Siena Serotonin (5-HT) is a decarboxylated derivative of trypthophan. Synthesized in enterochromaffin cells, it is released in circulation and incorporated into platelets. At the site of endothelial lesions, platelets aggregate and release 5-HT that presents several actions involved in atherogenesis: vasoconstriction in the presence of endothelial injury, aggregation of platelets, and mitogenesis of arterial muscle cells and endothelial cells. It may also contribute to the vascular inflammation associated with atherosclerosis by increasing the synthesis of Interleukin-6 in vascular muscle cells. If studies in vitro suggest an atherogenic role for 5-HT, a limited number of studies in vivo described a relation between 5-HT and atheroscierosis. We evaluated 5-HT in plasma and platelets of patients with unstable angina and stroke to identify an association between 5-HT and atherosclerosis of coronary and cerebral arteries. Twenty patients (14 men, 6 women, mean age 69±10 years) with unstable angina and 15 patients (7 men, 8 women, mean age 81±10 years) with stroke were included in the study. Twenty-four healthy subjects (10 men, 14 women, mean age 31=1=6 years) constituted the control group. Blood samples were drawn to determine plasma and platelet 5-HT concentrations. Serotonin was determined by HPLC. We observed that 5-HT levels in platelets in patients with unstable angina (105±46 ng/200000 cell) were significantly lower (p
M Fazia 1, A Iezzi 1, B Pinil,C Cuccurullo 1, M Zucchellil, D De Cesare z, S Ucchino z, F SpigonardoZ, M de Luca 1, SM Pre s co tt 2, F CuccurulloZ,A M e z z e t t i z, F Cipollone z 1University of Chieti "G. d'Annunzio", Italy; 2University of Utah, USA Inducible cyclooxygenase (COX-2) and prostaglandin (PG) E synthase (mPGES-1) are up-regulated in unstable plaques, contributing to their vulnerability through PGE2-dependent release of metalloproteinases (MMPs). In addition to COX, arachidonic acid (AA) can be substrate for the fatty acid-CoA rigase (FACL) 4,whose expression could therefore limit PGE2 release. Aim of our study was to evaluate FACL4 expression in plaques and correlate it with inflammatory infiltration and PGE2dependent MMP activity. Plaques were obtained from 60 patients who underwent carotid endarterectomy and divided into 2 groups (Symptomatic and Asymptomatic) according to recent evidence of stroke. Plaques were analyzed for CD68+ macrophages, CD3+ T cells, FACL4, COX-2, mPGES-1, MMP-2 and MMP-9 by immunohistochemistry and western blot; zymography was used to detect MMP activity. Inflammatory area was larger (P<0.O001) in symptomatic plaques. FACL4 staining was lower in symptomatic than in asymptomatic plaques (8+/-3% vs 23+/-5%, P<0.O001), and always associated with higher MMP-2 and MMP-9 expression. All symptomatic plaques contained activated MMPs. In contrast, COX-2 and mPGES-1 expression was higher in vulnerable plaques (P<0.O001). Double immunofluorescence co-localized FACL4 with COX-2, mPGES-1 and MMPs in macrophages. This study provides the first evidence that reduced FACL4 expression in plaque macrophages is associated with acute ischemic syndromes possibly through ineffective removal of unesterified AA, leading to PGE2-induced MMP release and plaque rupture.