No abstract available.
Lipoprotein(a)*

BACKGROUND: Lipoprotein(a)[Lp(a)], an independent risk factor for athrosclerosis, consist of low density lipoprotein like particle and specific glycoprotein, apolipoprotein(a). The levels of Lp(a) are mainly determined by the genetic pleomorphism of apolipoprotein(a) and has been though not to be influenced by age, sex and other biochemical parameters. Recent reports have shown that the concentrations of Lp(a) are correlated with age in women. The purpose of this study was to invastigate the association of Lp(a) concentration with sex and age. METHODS: The concentrations of Lp(a) were measured in 3,707 women and 389 men, free of diseases and medications known to affect the lipid levels. Plasma Lp(a) concentration were measured by commercial radioimmunoassay kit and other lipid profiles by conventional method. RESULTS: In female, median Lp(a) concentration increased with age till the early sixth decade (P=.0000) and then decreased. If peri- and postmenopausal women were excluded in the fifth decades, the relation between age and Lp(a) disappeared. In male, Lp(a) concentration were not associated with age. Median Lp(a) concentrations were higher in females than in males in the fifth(p=.0039) and the sixth decades(p=.0007), The difference became negligible after the exclusion of peri- and postmenopausal woman in the fifth decade. CONCLUSION: The concentrations of Lp(a) were corrected with age only in female. Females had higher levels than males in the fifth and the sixth decades. The relations are thought to be nither due to aging process nor sex but due to postmenopausal increase of Lp(a).
Aging ; Apoprotein(a) ; Female ; Glycoproteins ; Humans ; Lipoprotein(a)* ; Lipoproteins ; Male ; Menopause ; Plasma ; Radioimmunoassay ; Risk Factors

BACKGROUND: Lipoprotein(a)[Lp(a)], an independent risk factor for athrosclerosis, consist of low density lipoprotein like particle and specific glycoprotein, apolipoprotein(a). The levels of Lp(a) are mainly determined by the genetic pleomorphism of apolipoprotein(a) and has been though not to be influenced by age, sex and other biochemical parameters. Recent reports have shown that the concentrations of Lp(a) are correlated with age in women. The purpose of this study was to invastigate the association of Lp(a) concentration with sex and age. METHODS: The concentrations of Lp(a) were measured in 3,707 women and 389 men, free of diseases and medications known to affect the lipid levels. Plasma Lp(a) concentration were measured by commercial radioimmunoassay kit and other lipid profiles by conventional method. RESULTS: In female, median Lp(a) concentration increased with age till the early sixth decade (P=.0000) and then decreased. If peri- and postmenopausal women were excluded in the fifth decades, the relation between age and Lp(a) disappeared. In male, Lp(a) concentration were not associated with age. Median Lp(a) concentrations were higher in females than in males in the fifth(p=.0039) and the sixth decades(p=.0007), The difference became negligible after the exclusion of peri- and postmenopausal woman in the fifth decade. CONCLUSION: The concentrations of Lp(a) were corrected with age only in female. Females had higher levels than males in the fifth and the sixth decades. The relations are thought to be nither due to aging process nor sex but due to postmenopausal increase of Lp(a).
Aging ; Apoprotein(a) ; Female ; Glycoproteins ; Humans ; Lipoprotein(a)* ; Lipoproteins ; Male ; Menopause ; Plasma ; Radioimmunoassay ; Risk Factors

BACKGROUND: The structure of lipoprotein(a) [Lp(a)] includes a low-density lipoprotein cholesterol (LDL-C) component and apolipoprotein(a) [apo(a)] linked to apolipoprotein B-100 of LDL-C with a disulfide bond. Liver cirrhosis is the only disease in which the decrease of serum Lp(a) concentra-tion is observed as a secondary effect. In this study, we tried to investigate the mechanisms for the Lp(a) decrease in cirrhotic patients. METHODS: Forty Child 's class A cirrhotic patients, 40 Child 's class C patients from Asan Medical Center, and 80 healthy controls were recruited. Serum concentrations of interleukin-6 (IL-6), LDL-C, Lp(a), and free apo(a) were measured. RESULTS: The serum concentrations of Lp(a) in the Child 's class C patients were significantly lower than those in class A and the control group (P < 0.05). The apo(a) concentrations in the Child 's class C patients were significantly lower than those in class A and the control group (P < 0.05). The LDL-C concentrations of Child 's class C patients were significantly lower than those in class A and the con-trol group (P < 0.01). The IL-6 concentrations of Child 's class C patients were significantly higher than those in class A and the control group (P < 0.005). Serum concentrations of Lp(a) showed positive correlations with those of LDL-C (r=0.42, P < 0.0001) and with those of the free apo(a) (r=0.68, P < 0.0001). But serum concentrations of IL-6 had no correlation to those of the Lp(a) or the free apo(a). CONCLUSIONS: Considering the positive correlation between Lp(a) and LDL-C, the decrease in the serum Lp(a) in cirrhotic patients could be due mainly to the decrease in the LDL component, although we could not suggest the mechanism for the LDL decrease.
Apolipoprotein B-100 ; Apolipoproteins* ; Apoprotein(a)* ; Child ; Cholesterol ; Cholesterol, LDL* ; Chungcheongnam-do ; Humans ; Interleukin-6 ; Lipoprotein(a)* ; Lipoproteins* ; Liver Cirrhosis* ; Liver*

Lipoprotein(a), a complex formed by apolipoprotein(a), apo B-100 and lipids, is considered an independent, genetically determined, predictor of cardiovascular disease. It may have antifibrinolytic properties in view of its similarity to plasmmogen. To evaluate whether lipoprotein(a) may be a risk factors in patients with diabetic retinopathy or not, we measured the circulating serum level of lipoprotein(a) in each group classified by the severity of diabetic retinopathy and control group. The serum lipoprotein(a) level was higher in the diabetic patients than in the control group, and diabetic retinopathy, which was expressed by the grade of retinopathy in the worse eye, was correlated significantly with the duration of disease, and the serum level of lipoprotein(a) independently(P<0.05). There was no correlation between the diabetic retinopathy and the age at the time of diagnosis, systolic or diastolic blood pressure, or the serum levels of HbA(IC), cholesterol, triglyceride, and total lipid. We concluded that the lipoprotein(a) may play a role as one of the independent risk factors in diabetic retinopathy.
Apolipoprotein B-100 ; Apoprotein(a) ; Blood Pressure ; Cardiovascular Diseases ; Cholesterol ; Diabetic Retinopathy* ; Diagnosis ; Humans ; Lipoprotein(a)* ; Risk Factors ; Triglycerides

Lipoprotein(a)[Lp(a)] represents a class of lipoprotein particles defined by the presence of apolipoprotein(a), a unique glycoprotein linked by a disulfide bond to apolipoprotein B-100 to form a single macromolecule. It was known that Lp(a) levels were associated with risk factor for cardiovascular disease and were fluctuated during pregnancy and postpartum. In the present study, plasma Lp(a) levels were estimated in two groups of women comprising 48 normal spontaneous vaginal delivery group and 52 Cesarean section delivery group. The changes of plasma Lp(a) concentrations were serially estimated before delivery, postpartum 1 weeks and postpartum 6 weeks. The result can be summarized as follows.1. Mean ploasma Lp(a) levels were changed from 43.9 +/- 28.4 mg/dl at delivery to 68.5 +/- 35.5 mg/dl at postpartum 1 weeks 73.1 +/- 35.7 mg/dl versus 63.7 +/- 35.1 mg/dl. And after postpartum 6 weeks, mean plasma Lp(a) levels were returned to near initial levels 48.4 +/- 21.1 mg/dl versus 42.2 +/- 16.7 mg/dl.3. Lp(a) levels were significantly rised postpartum 1 weeks compared with before delivery(p < 0.05) and after postpatum 6 weeks(p < 0.05). In conclusion, serum Lp(a) levels were increased postpartum 1 weeks with significant value, and returned to initial levels after postpartum 6 weeks. Our findings suggests that Lp(a) has the characteristics of an acute phase reactant rather modulated by endogenous hormone.
Apolipoprotein B-100 ; Apoprotein(a) ; Cardiovascular Diseases ; Cesarean Section ; Female ; Glycoproteins ; Humans ; Lipoprotein(a)* ; Lipoproteins ; Plasma* ; Postpartum Period* ; Pregnancy ; Risk Factors

OBJECTIVETo assess the atherogenicity of lipoprotein(a), the effect of the heterogeneity of lysine binding of apolipoprotein(a) [apo(a)], a plasminogen-like glycoprotein component on the proliferation of human arterial smooth muscle cells (SMCs).

METHODSBoth wild type (wt) Trp72 and mutant (mut) Trp72-->Arg forms of apo(a) kringle IV-10 were expressed by employing a GST-gene fusion system into E. coli. The proliferation of SMCs was determined by flow cytometry and MTT colorimetry. Enzyme-linked immunosorbent assay (ELISA) assay was used to detect the active form of transforming growth factor beta(1) (TGF-beta(1)).

RESULTSApo(a) wt-kringle IV-10 that has lysine binding properties possessed a growth-stimulating activity to SMCs on a dose-dependence manner by stimulating cells in the G(1)/G(0) phase of cell cycle to S and G(2)/M phase, and reduced significantly the amounts of endogenous active TGF-beta(1) in culture when compared with the control medium and the GST group (2.4 +/- 0.5 vs 8.6 +/- 1.6 and 9.1 +/- 1.7 ng/ml, P < 0.01). The growth-stimulating effect of apo(a) mut-kringle IV-10 deficient in lysine binding was negligible.

CONCLUSIONSApo(a) induces SMCs growth by inhibiting the activation of latent TGF-beta(1), an activity that may involve the ability of apo(a) kringle IV-10 to bind lysine. The mitogenic effect of apo(a) wt-kringle IV-10 on SMCs might play an active role in the atherogenic function of lipoprotein(a).

Apolipoproteins ; genetics ; metabolism ; Apoprotein(a) ; Cell Division ; physiology ; Humans ; In Vitro Techniques ; Kringles ; genetics ; Lipoprotein(a) ; genetics ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Transforming Growth Factor beta ; metabolism

BACKGROUND: Lipoprotein (a) [Lp(a)] contains apolipoprotein(a), which is a structural homologue of plasminogen and competes with it for binding sites. It also acts by increasing plasminogen activator inhibitor-1 expression. The objective of this study was to evaluate the relationship between Lp(a) levels and restenosis rate after successful coronary stent placement. METHODS: The study included 306 patients who underwent coronary stent placement and follow-up coronary angiogram at Chonnam National University Hospital from August 1996 to June 2000. Restenosis rate was analyzed according to the level of Lp(a); Group I with high Lp(a) (n=7, Lp(a) 36 mg/dL, 58.98.8 years, female: 35.1%) and Group II with low Lp(a) (n=29, Lp(a) < 36 mg/dL, 57.79.8 years, female: 18.8%). RESULTS: 1) There was no significant differences in risk factors of atherosclerosis, clinical diagnosis, the number of involved coronary artery, left ventricular function, angiographic lesion characteristics by American College of Cardiology/American Heart Association clasification and Thrombolysis In Myocardial Infarction flow in two groups. 2) Angiographic restenosis rates were not different between two groups (group I : 33.8%, group II : 35.4%). CONCLUSION: Plasma Lp(a) levels are not related with the angiographic restenosis rate after coronary stent placement.
Apoprotein(a) ; Atherosclerosis ; Binding Sites ; Coronary Vessels ; Diagnosis ; Female ; Follow-Up Studies ; Heart ; Humans ; Jeollanam-do ; Lipoprotein(a)* ; Myocardial Infarction ; Plasma ; Plasminogen ; Plasminogen Activators ; Risk Factors ; Stents* ; Ventricular Function, Left

BACKGROUND: Lipoprotein(a) [Lp(a)] is an atherogenic lipoprotein that is assembled from a low density lipoprotein(LDL) and apolipoprotein(a) [apo(a)]. The variations in Lp(a) concentration tend to be inversely related to the number of kringle IV in apo(a) gene, but other polymorphisms [pentanucleotide(TTTTA) repeats, +93 C/T polymorphism, and Met/Thr polymorphism] of the apo(a) gene are also seems to be related to Lp(a) concentrations. The purpose of this study was to investigate the association of the pentanucleotide repeat polymorphism(PNRP) and Met/Thr polymorphism with the Lp(a) concentrations. METHODS: We studied 197 healthy adults. For genotype analysis of the PNRP and the Met/Thr polymorphism, PCR was performed. Apo(a) phenotyping was performed by SDS-PAGE and immunoblotting. The Lp(a) concentrations were measured by ELISA method. More than two groups were compared using the Kruskal Wallis one-way analysis test. To establish a relationship between gene polymorphisms and Lp(a) concentrations, The linear regression test was performed. RESULTS: Mean Lp(a) concentration was 25.3+/-21.5 mg/dL. Allele frequencies for PNRP, subjects with 8/8 genotype were 114(57.9%) and most frequently observed. The Lp(a) concentrations showed the tendency to decrease as the sum of alleles of PNR increased. Subjects with Met/Thr genotype were 119(60.4%), Met/Met genotype were 71(36.0%) and Thr/Thr genotype were 7(3.6%). CONCLUSIONS: For PNRP, subjects with 8/8 genotype were 114(57.9%) and 8/8 genotype was the most frequently observed. Met/Thr genotype was most frequently observed.
Adult ; Alleles* ; Apoprotein(a) ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Gene Frequency* ; Genotype ; Humans ; Immunoblotting ; Kringles ; Linear Models ; Lipoprotein(a) ; Lipoproteins ; Microsatellite Repeats ; Polymerase Chain Reaction

No abstract available.
Hypercholesterolemia* ; Lipoprotein-X* ; Lipoproteins*