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2.P.70 Effect of policosanol on smooth muscle cell proliferation in the cuffed carotid artery of the rabbit
Tuesday 7 October Lipid-lowering
I-.. 2 P 69 1 Effect
of itraconazole on serum concentrations of sbnvastatin and pravastatin
P.J. Neuvonen, Pharmacology,
T. Kantola, University
K.T. Kivistii. of Helsinki,
P
70
Department of Clinical FIN-00290 Helsinki, Finland
M. Noa =a\
Effect of policosanol on smooth muscle cell proliferation cuffed carotid artery of tbe rabbit R. ML, R. Mesa, M.E. Ramos. Center for Scientific Research,
Center of Natural Havana, Cuba
in the
Products:
Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane (Sac&rum ofJicinurum, L.) wax, with cholesterol lowering effects proved in experimental models and patients with type II hypercholesterolemia. It acts by inhibiting cholesterol biosynthesis and increasing receptor dependent LDL-processing. This study was conducted to determine whether policosanol prevents smooth muscle cell proliferation in the cuffed carotid artery of New Zealand rabbit. Silicone collars were placed around the left carotid artery of rabbits for 15 days. The contralateral carotid artery was sham-operated. ‘lSvo experimental groups received also policosanol at 5 and 25 m&g during this time. All segments of carotid arteries were examined by light and electron microscopy. To evaluate intimal thickening the cross-sectional area of intima and media was measured. A significant reduction of the neointima formation in policosanol-treated animals was observed. It is concluded that policosanol has a protective effect on the neointima formation in this experimental model.
] 2.P.71 1 NK-104, a potent HMGCoA-reductase inhibitor, increases intracellular degradation of apo B-100 and decreases its secretion in HepG2 cells
Atorvastatin inhibition of NF-wB activation in vascular smooth muscle cells is mediated by protein isoprenylation blockade
M. Ortega, Fundaci6n
C. Bustos, M. HemBndez-Press, C. Cuijarro, J. Tuti6n, J/m&ez Diaz, Universidad Autdnoma, Madrid, Spain
J. Egido.
Cardiovascular mortality, which is mainly due to the rupture of unstable atherosclerotic plaques, is reduced by HMG-CoA reductase inhibitors. The presence of inflammatory cells within the lesion is favored by the release of chemotactic factors by resident cells and is a marker of its vulnerability. We have previously shown that nuclear factor KB, an activator of chemokine gene transcription, is increased in the atherosclerotic lesion (Hemtidez-F’resa et al. 1997. Circulation 95: 1532-1541). In cultured VSMC, we now study the effect of atorvastatin (Atv) on the activity of nuclear factors NF-KB and m-1 (a nuclear factor involved in the regulation of extracellular matrix genes) upon stimulation by agents that are overexpressed in the atherosclerotic lesion. NF-KB activity (Electrophoretic mobility shift assay) was increased in VSMC by angiotensin II (Ang II) (Zfold) and TNFa! (7.5.fold) (p < 0.05). AP-1 activation was increased by Ang II (5-fold) and TNFu (3-fold). F’reincubation whit Atv (10m7 M) diminished NF-KB activation by 45% and 70%. respectively (p < 0.05). However, no clear modulation of AP-1 activation was noted. The effect of Atv on NF-KB activity seems to be dependent on non sterol isoprenoids on since farnesyl pyrophosphate and geranylgeranyl pyrophosphate (5 PM) reversed the inhibition of Atv. Moreover, manumycin A (50 PM), a famesyl transfer&se inhibitor, completely blocked the activation of NF-KB. These results indicate that Atv inhibition of NF-KB is specific and probably mediate by the blockade of protein isoprenylation. These data could help to explain the beneficial effect of statins on cardiovascular mortality in clinical tria’s.
2 P.73 CYI
Ektending the dosing range for sbnvastatim The efficacy and safety of Siivastatin 80 mg/d
L. Ose’ L. A. Corsetti2, A.C. Tate2, A. Shahane2, Y.B. Mitche12. 7’he -7 Expanded Dose Simvastatin International Study Group; ‘Oslo, Norway: 2Merck Re::earch Labs, Rahway, New Jersey USA Greater reductions in LDL-cholesterol (C) are associated with larger reductions in clinical coronary events. Based on the excellent safety profile of simvastatin (S) at doses up to 40 mg/d, the efficacy and safety of S 80 mg/d was evaluated in a multicenter, double blind, parallel study in 580 hypercholesterolemic patients. Subjects were randomized to S 40 or 80 mg/d in a ratio of 2:3 for a period of 6 months and followed at 6 week intervals; all lab tests were performed centrally. The baseline (BL) C, triglycerides (TG), and % change averaged over weeks 18 and 24 are shown below.
BL (mm&L)
Intracellular cholesterol biosynthesis may play a key role in supplying cholesterol (as cholesteryl ester) for the neutral core of very low density lipoprotein, thus modulating the secretion of apolipoprotein B-100 (apoB-100) from hepatocytes. We studied the effects of compound NK-104, a competitive inhibitor of HMGCoA-Reductase on apoB-100 synthesis and secretion from the human hepatoma cell line HepG2. Cells were preincubated with NK-104 (0.01-5 KM) for 24 h. The incubation with the drug continued for further 4 h in the presence of absence of oleate (0.8 mM). ApoB-100 in the medium was determined by an ELISA assay using a murine monoclonal antibody for the capture and a rabbit polyclonal antibody for detection. Incubation of HepG2 with NK-104 resulted in a marked inhibition of cholesterogenesis, determined as incorporation of [‘4C]-acetate into sterol, and decreased in a dose-dependent manner apoB-100 secretion (about -20% vs control, both in basal condition and after incubation with oleate). Distribution of apoB-100 secreted in density gradient showed that this decrease was essentially due to a reduction of apoB-100 associated with lipoproteins in the density range of LDL. Pulse-chase experiment demonstrated that NK-104 did not affect the synthetic rate of apoB-100 but increased intracellular degradation of newly synthesized protein. The compound had only marginal effect on the mass of intracellular triglyceride and decreased intracellular mass of free cholesterol and cholesterol esters. In summary compound NK-104 decreases apoB-100 seSymposium
rzl2.P72
40 mg/d (n = 227)
C. Ooven’, A.M. Bersino’ , A.L. Catapano’ ‘. ‘Institute of Pharmacological Sciences 2Centro per lo Studio dell’Aterosclerosi, University of Milano, Milano, Italy
11th International
131
cretion by HepG2 cells. The effect occurs post-translationally and is related to the inhibition of synthesis and cellular cholesterol content induced by NK-104.
ltraconazole is a potent inhibitor of CYP3A4 and it increases more than lo-fold plasma concentrations of lovastatin and lovastatin acid. We have studied the effect of itraconazole on serum simvastatin and pravastatin in 2 double-blind, randomized, 2-phase crossover studies, both comprising 10 healthy volunteers. They ingested either 200 mg itraconazole or placebo once a day for 4 days. On day 4, they ingested a single 40 mg dose of simvastatin or pravastatin. Serum concentrations of simvastatin and pravastatin were measured up to 24 hours. Itraconazole increased the area under the concentration-time curve (AU&& of simvastatin 19-fold [52 rt 5 (mean k SE) vs. 977 f 126 ng.h/ml; p < O.OOl] and the peak concentration (C,) 17-fold (13 f 2 vs. 217 f 40 ng!ml; p < 0.001) but the half-life (T1/2) was prolonged only slightly (3.1 & 0.2 vs. 3.9 & 0.2 h). The AUCof pravastatin was not significantly increased (89 i 33 vs. 152 & 47 ngh/ml) by itraconazole. Neither was the C, (37 & 13 vs. 66 f 23 rig/ml) nor the TI/Z (1.7 -f 0.2 vs. 1.8 & 0.2 h) of pravastatin changed significantly by itraconazole. In conclusion, simvastatin as a substrate of CYF’3A4 is susceptible to important interactions with itraconazole and other potent inhibitors of CYP3A4. ltraconazole is not likely to increase markedly serum pravastatin, obviously because pravastatin is not metabolized by CYP3A4.
rl2
1997: Posters drugs
Total C LDL-C TG’ HDL-C
80 mg/d (n = 353)
% change
8.50 6.40 I .66 1.30
-32 -43 -19 II
BL (mm&L) 8.32 6.22 1.70 1.27
W change -37” -48;’ -24. IO
median; lxcween groups * p = 0.005, ** p < O.M)l
Both doses were well tolerated with no significant differences between groups in the incidence of clinical or laboratory adverse experiences. Hepatic and muscle enzyme abnormalities occurred infrequently with both doses. Summary: S 80 mg/d was more effective and had a comparable safety profile to the 40 mg dose. The greater degree of LDL-C lowering obtained with the 80 mg dose will allow more high risk patients to achieve their LDL-C and TG therapeutic goals as recommended by expert panels. Supported from a grant by Merck and Co.
Lxl2 P
74
EfEaxcy aud safety of ciprofibrate and lovastatin in treatment of hyperlipidemia
H S. Park Y.S. Kim, H.C. Shin’, W.S. Choi’ , H.R. Lee’. Department TMedicine, Asan Medical Center; ‘College of Medicine, Ulsan University, Catholic Medical College; 2Yonsei University; 388-I Poongnapdong Songpagu, Seoul, Korea To comp;lre
on Atherosclerosis,
the efficacy Paris,
and safety of ciprofibrate
October
1997
and lovastatin,
of
we conducted
I-.. 2 P 69 1 Effect
of itraconazole on serum concentrations of sbnvastatin and pravastatin
P.J. Neuvonen, Pharmacology,
T. Kantola, University
K.T. Kivistii. of Helsinki,
P
70
Department of Clinical FIN-00290 Helsinki, Finland
M. Noa =a\
Effect of policosanol on smooth muscle cell proliferation cuffed carotid artery of tbe rabbit R. ML, R. Mesa, M.E. Ramos. Center for Scientific Research,
Center of Natural Havana, Cuba
in the
Products:
Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane (Sac&rum ofJicinurum, L.) wax, with cholesterol lowering effects proved in experimental models and patients with type II hypercholesterolemia. It acts by inhibiting cholesterol biosynthesis and increasing receptor dependent LDL-processing. This study was conducted to determine whether policosanol prevents smooth muscle cell proliferation in the cuffed carotid artery of New Zealand rabbit. Silicone collars were placed around the left carotid artery of rabbits for 15 days. The contralateral carotid artery was sham-operated. ‘lSvo experimental groups received also policosanol at 5 and 25 m&g during this time. All segments of carotid arteries were examined by light and electron microscopy. To evaluate intimal thickening the cross-sectional area of intima and media was measured. A significant reduction of the neointima formation in policosanol-treated animals was observed. It is concluded that policosanol has a protective effect on the neointima formation in this experimental model.
] 2.P.71 1 NK-104, a potent HMGCoA-reductase inhibitor, increases intracellular degradation of apo B-100 and decreases its secretion in HepG2 cells
Atorvastatin inhibition of NF-wB activation in vascular smooth muscle cells is mediated by protein isoprenylation blockade
M. Ortega, Fundaci6n
C. Bustos, M. HemBndez-Press, C. Cuijarro, J. Tuti6n, J/m&ez Diaz, Universidad Autdnoma, Madrid, Spain
J. Egido.
Cardiovascular mortality, which is mainly due to the rupture of unstable atherosclerotic plaques, is reduced by HMG-CoA reductase inhibitors. The presence of inflammatory cells within the lesion is favored by the release of chemotactic factors by resident cells and is a marker of its vulnerability. We have previously shown that nuclear factor KB, an activator of chemokine gene transcription, is increased in the atherosclerotic lesion (Hemtidez-F’resa et al. 1997. Circulation 95: 1532-1541). In cultured VSMC, we now study the effect of atorvastatin (Atv) on the activity of nuclear factors NF-KB and m-1 (a nuclear factor involved in the regulation of extracellular matrix genes) upon stimulation by agents that are overexpressed in the atherosclerotic lesion. NF-KB activity (Electrophoretic mobility shift assay) was increased in VSMC by angiotensin II (Ang II) (Zfold) and TNFa! (7.5.fold) (p < 0.05). AP-1 activation was increased by Ang II (5-fold) and TNFu (3-fold). F’reincubation whit Atv (10m7 M) diminished NF-KB activation by 45% and 70%. respectively (p < 0.05). However, no clear modulation of AP-1 activation was noted. The effect of Atv on NF-KB activity seems to be dependent on non sterol isoprenoids on since farnesyl pyrophosphate and geranylgeranyl pyrophosphate (5 PM) reversed the inhibition of Atv. Moreover, manumycin A (50 PM), a famesyl transfer&se inhibitor, completely blocked the activation of NF-KB. These results indicate that Atv inhibition of NF-KB is specific and probably mediate by the blockade of protein isoprenylation. These data could help to explain the beneficial effect of statins on cardiovascular mortality in clinical tria’s.
2 P.73 CYI
Ektending the dosing range for sbnvastatim The efficacy and safety of Siivastatin 80 mg/d
L. Ose’ L. A. Corsetti2, A.C. Tate2, A. Shahane2, Y.B. Mitche12. 7’he -7 Expanded Dose Simvastatin International Study Group; ‘Oslo, Norway: 2Merck Re::earch Labs, Rahway, New Jersey USA Greater reductions in LDL-cholesterol (C) are associated with larger reductions in clinical coronary events. Based on the excellent safety profile of simvastatin (S) at doses up to 40 mg/d, the efficacy and safety of S 80 mg/d was evaluated in a multicenter, double blind, parallel study in 580 hypercholesterolemic patients. Subjects were randomized to S 40 or 80 mg/d in a ratio of 2:3 for a period of 6 months and followed at 6 week intervals; all lab tests were performed centrally. The baseline (BL) C, triglycerides (TG), and % change averaged over weeks 18 and 24 are shown below.
BL (mm&L)
Intracellular cholesterol biosynthesis may play a key role in supplying cholesterol (as cholesteryl ester) for the neutral core of very low density lipoprotein, thus modulating the secretion of apolipoprotein B-100 (apoB-100) from hepatocytes. We studied the effects of compound NK-104, a competitive inhibitor of HMGCoA-Reductase on apoB-100 synthesis and secretion from the human hepatoma cell line HepG2. Cells were preincubated with NK-104 (0.01-5 KM) for 24 h. The incubation with the drug continued for further 4 h in the presence of absence of oleate (0.8 mM). ApoB-100 in the medium was determined by an ELISA assay using a murine monoclonal antibody for the capture and a rabbit polyclonal antibody for detection. Incubation of HepG2 with NK-104 resulted in a marked inhibition of cholesterogenesis, determined as incorporation of [‘4C]-acetate into sterol, and decreased in a dose-dependent manner apoB-100 secretion (about -20% vs control, both in basal condition and after incubation with oleate). Distribution of apoB-100 secreted in density gradient showed that this decrease was essentially due to a reduction of apoB-100 associated with lipoproteins in the density range of LDL. Pulse-chase experiment demonstrated that NK-104 did not affect the synthetic rate of apoB-100 but increased intracellular degradation of newly synthesized protein. The compound had only marginal effect on the mass of intracellular triglyceride and decreased intracellular mass of free cholesterol and cholesterol esters. In summary compound NK-104 decreases apoB-100 seSymposium
rzl2.P72
40 mg/d (n = 227)
C. Ooven’, A.M. Bersino’ , A.L. Catapano’ ‘. ‘Institute of Pharmacological Sciences 2Centro per lo Studio dell’Aterosclerosi, University of Milano, Milano, Italy
11th International
131
cretion by HepG2 cells. The effect occurs post-translationally and is related to the inhibition of synthesis and cellular cholesterol content induced by NK-104.
ltraconazole is a potent inhibitor of CYP3A4 and it increases more than lo-fold plasma concentrations of lovastatin and lovastatin acid. We have studied the effect of itraconazole on serum simvastatin and pravastatin in 2 double-blind, randomized, 2-phase crossover studies, both comprising 10 healthy volunteers. They ingested either 200 mg itraconazole or placebo once a day for 4 days. On day 4, they ingested a single 40 mg dose of simvastatin or pravastatin. Serum concentrations of simvastatin and pravastatin were measured up to 24 hours. Itraconazole increased the area under the concentration-time curve (AU&& of simvastatin 19-fold [52 rt 5 (mean k SE) vs. 977 f 126 ng.h/ml; p < O.OOl] and the peak concentration (C,) 17-fold (13 f 2 vs. 217 f 40 ng!ml; p < 0.001) but the half-life (T1/2) was prolonged only slightly (3.1 & 0.2 vs. 3.9 & 0.2 h). The AUCof pravastatin was not significantly increased (89 i 33 vs. 152 & 47 ngh/ml) by itraconazole. Neither was the C, (37 & 13 vs. 66 f 23 rig/ml) nor the TI/Z (1.7 -f 0.2 vs. 1.8 & 0.2 h) of pravastatin changed significantly by itraconazole. In conclusion, simvastatin as a substrate of CYF’3A4 is susceptible to important interactions with itraconazole and other potent inhibitors of CYP3A4. ltraconazole is not likely to increase markedly serum pravastatin, obviously because pravastatin is not metabolized by CYP3A4.
rl2
1997: Posters drugs
Total C LDL-C TG’ HDL-C
80 mg/d (n = 353)
% change
8.50 6.40 I .66 1.30
-32 -43 -19 II
BL (mm&L) 8.32 6.22 1.70 1.27
W change -37” -48;’ -24. IO
median; lxcween groups * p = 0.005, ** p < O.M)l
Both doses were well tolerated with no significant differences between groups in the incidence of clinical or laboratory adverse experiences. Hepatic and muscle enzyme abnormalities occurred infrequently with both doses. Summary: S 80 mg/d was more effective and had a comparable safety profile to the 40 mg dose. The greater degree of LDL-C lowering obtained with the 80 mg dose will allow more high risk patients to achieve their LDL-C and TG therapeutic goals as recommended by expert panels. Supported from a grant by Merck and Co.
Lxl2 P
74
EfEaxcy aud safety of ciprofibrate and lovastatin in treatment of hyperlipidemia
H S. Park Y.S. Kim, H.C. Shin’, W.S. Choi’ , H.R. Lee’. Department TMedicine, Asan Medical Center; ‘College of Medicine, Ulsan University, Catholic Medical College; 2Yonsei University; 388-I Poongnapdong Songpagu, Seoul, Korea To comp;lre
on Atherosclerosis,
the efficacy Paris,
and safety of ciprofibrate
October
1997
and lovastatin,
of
we conducted