[What the surgeon needs to know about basic new concepts of inflammation and their therapeutic consequences: sanitation of inflammation is not a passive but rather an active process regulated by lipid mediators]. / Was der Chirurg über grundlegend neue Konzepte zur Entzündung und deren therapeutische Konsequenzen wissen sollte: Die Ausheilung der Entzündung ist kein passiver, sondern ein durch Lipidmediatoren regulierter aktiver Prozess.

The acute inflammatory response as a physiological programme that protects the organism against injurious pathogens is characterised by highly regulated actions of pro- and anti-inflammatory mediators. Intensive investigations during the last decades have led to the identification of these mediators and their complex interplay as well as the design and development of anti-inflammatory therapies. However, the resolution of acute inflammation has long been considered to be a passive process. In consequence, little was known about the mechanisms which guide acute inflammation either to complete resolution, repair of inflamed tissue and restoration of normal function or to a chronic inflammatory process characterised by persistent signs of inflammation, tissue damage and impaired function. Predominantly during the last decade the so-called specialised proresolving mediators (SPM) have been identified. These essential fatty acid-derived mediators - lipoxins, resolvins, protectins, and maresins - terminate the acute inflammatory responses and stimulate their complete resolution. SPM possess both anti-inflammatory and proresolving activities in that they inhibit pro-inflammatory cytokines, limit infiltration of neutrophils, enhance macrophage uptake, and finally stimulate their non-phlogistic activation and clearance of apoptotic neutrophils and microbial particles. It has been demonstrated in multiple animal models of human inflammatory diseases that, e.g., atherosclerosis, diabetes, and inflammatory bowel diseases are caused by a decreased synthesis and/or an impaired signal transduction of the proresolving mediators. Future studies are warranted to clarify whether these proresolving lipid mediators will participate in healing human inflammatory diseases and their complications.

CD14 promoter polymorphism (- 159C-->t) is not associated with myocardial infarction or coronary artery disease in patients with assumed high genetic risk.

OBJECTIVE: Inflammation plays a major role in the pathogenesis of coronary artery disease (CAD) and myocardial infarction (MI). CD14 is the receptor for bacterial lipopolysaccharide in monocytes and mediates the production of proinflammatory cytokines. The promoter of the CD14 gene has a polymorphic site in position - 159 (C-->T) and T-homozygotes have been shown to express higher amounts of CD14 by some investigators. We and others have found an association of the T-allele with past MI in former studies, but reports in the literature are contradictory. METHODS AND RESULTS: We investigated a study group with an assumed high genetic risk by selecting 200 patients suffering from angiographically verified CAD or MI who were younger than 50 years or who had only one or no risk factor (hypertension, smoking, elevated body mass index, impaired glucose tolerance or elevated cholesterol levels). We used 252 healthy subjects as controls. Additionally, the levels of soluble (s) CD14 in plasma and amount of membranous (m) CD14 on the surface of monocytes were determined in different genotypes. We found no association of either genotype with CAD, extent of CAD, or a history of MI. No significant correlation was found after adjustment for vascular risk factors. In addition, no significant differences in the density of monocyte mCD14 or in plasma levels of sCD14 were detectable among the various genotypes. CONCLUSIONS: The assumed weak association of the TT-genotype of the CD14 promoter polymorphism with MI could not be not established in a well-defined group of young patients with a high genetic risk. The association of the polymorphism with expression of sCD14 or mCD14 was not confirmed.

CREM-transgene mice: An animal model of atrial fibrillation and thrombogenesis.

BACKGROUND: The molecular pathomechanisms underlying atrial thrombogenesis are multifactorial and still require detailed investigations. Transgenic mice with cardiomyocyte-directed expression of the transcriptional repressor CREM-IbΔC-X (CREM-TG) represent an experimental model of atrial fibrillation (AF) that shows a gradual, age-dependent progression from atrial ectopy to persistent AF. Importantly, this model develops biatrial thrombi. The molecular characteristics related to the thrombogenesis in CREM-TG mice have not been studied, yet. METHODS: The inflammatory and prothrombotic state was evaluated at the transcriptional (qRT-PCR) and protein level in the left (LA) and right atria (RA) from CREM-TG mice at the age of 20weeks and compared to wild-type controls. Moreover, histological analyses of atrial thrombi were performed. RESULTS: The endocardial dysfunction was mirrored by diminished levels of eNOS-mRNA in both atria (RA: 0.79±0.04, LA: 0.72±0.06; each P<0.05). Moreover, the PAI-1/t-PA mRNA ratio was significantly increased in both atria (RA: 3.6±0.6; P<0.01, LA: 4.0±1.0; P<0.05) indicating a high risk of thrombus formation. However, the inflammatory phenotype was more pronounced in the RA and was reflected by a significant increase in the mRNA levels encoding adhesion molecules ICAM-1 (2.1±0.2; P<0.01), VCAM-1 (2.3±0.5; P<0.05), and selectin P (3.6±0.5: P<0.05). CONCLUSIONS: CREM-TG mice represent a valuable model for studying atrial thrombogenesis and assessing therapeutic approaches preventing embolic events in the systemic and pulmonary circulation.

Protective regulation of the ACE2/ACE gene expression by estrogen in human atrial tissue from elderly men.

Data from animal experiments and clinical investigations suggest that components of the renin-angiotensin system are markedly affected by sex hormones. However, whether estrogen affects human atrial myocardium has not been investigated yet. In this study, we determined the effects of estrogen on key components of atrial renin-angiotensin system: angiotensin-converting enzyme, responsible for generation of angiotensin II and angiotensin-converting enzyme 2, counteracting majority of AngII effects, and different renin-angiotensin system receptors, AT1R, AT2R, and MAS. First, the expression levels of estrogen receptors mRNA were determined in right atrial appendages obtained from patients undergoing heart surgery. The amounts of estrogen receptor α and estrogen receptor ß mRNA were similar between women ( n = 14) and men ( n = 10). Atrial tissue slices (350 µm) were prepared from male donors which were exposed to estrogen (1-100 nM; n = 21) or stimulated at 4 Hz for 24 h in the presence or absence of 100 nM estrogen ( n = 16), respectively. The administration of estrogen did not change mRNA levels of estrogen receptors, but activated MAP kinases, Erk1/2. Furthermore, estrogen increased the amounts of angiotensin-converting enzyme 2-mRNA (1.89 ± 0.23; P < 0.05) but reduced that of angiotensin-converting enzyme-mRNA (0.78 ± 0.07, P < 0.05). In addition, the transcript levels of AT2R and MAS were upregulated by estrogen. Pacing of tissue slices significantly increased the angiotensin-converting enzyme/angiotensin-converting enzyme 2 ratio at both the mRNA and protein level. During pacing, administration of estrogen substantially lowered the angiotensin-converting enzyme/angiotensin-converting enzyme 2 ratio at the transcript (0.92 ± 0.21 vs. 2.12 ± 0.27 at 4 Hz) and protein level (0.94 ± 0.20 vs. 2.14 ± 0.3 at 4 Hz). Moreover, estrogen elicited anti-inflammatory and anti-oxidative effects on renin-angiotensin system-associated downstream effectors such as pro-oxidative LOX-1 and pro-inflammatory ICAM-1. An antagonist of estrogen receptor α reversed these anti-inflammatory and anti-oxidative effects of estrogen significantly. Overall, our results demonstrated that estrogen modifies the local renin-angiotensin system homeostasis and achieves protective effects in atrial myocardium from elderly men. Impact statement The present study demonstrates that estrogen affects the human atrial myocardium and mediates protective actions through estrogen receptors-(ER) dependent signaling. Estrogen substantially modulates the local RAS via downregulation of ACE and simultaneous upregulation of ACE2, AT2R and MAS expression levels. This is indicative of a shift of the classical RAS/ACE axis to the alternative, protective RAS/ACE2 axis. In support of this view, estrogen attenuated the expression of RAS-associated downstream effectors, LOX-1, and ICAM-1. A specific antagonist of ERα reversed the anti-inflammatory and anti-oxidative effects of estrogen in paced and non-paced atrial tissue slices. In summary, our data demonstrate the existence of protective effects of estrogen in atrial tissue from elderly men which are at least in part, mediated by the regulation of local RAS homeostasis.

Intraportal transplantation of pancreatic islets into livers of diabetic rats. Reinnervation of islets and regulation of insulin secretion by the hepatic sympathetic nerves.

Two weeks after intraportal transplantation of 2,000 neonatal pancreatic islets, recipient rats completely recovered from streptozotocin-induced diabetes. The reversal of diabetes could be documented by the normalization of blood glucose levels, by a restored weight gain, by normal glucagon and insulin levels in blood, and by a disappearance of polyuria and polydipsia. The reversal remained stable for at least 9 months. This study determined whether intraportally transplanted pancreatic islets were reinnervated after transplantation and whether the secretion of insulin and glucagon from pancreatic islets might be modulated by the vegetative innervation of recipient livers. Predominantly catecholaminergic but also cholinergic nerve fibers were detected not only within the portal tracts around hepatic arteries, portal veins, and bile ducts, but also at the borderline of hepatocytes and beta-cells and in islet cell complexes between beta-cells. Corresponding electron micrographs showed beta-cells in close contact with axons of nonmyelinated nerve fibers. Isolated livers were single pass perfused via both the hepatic artery and the portal vein. An increase in glucose level from 5 to 14 mmol/l enhanced hepatic glucose uptake and increased insulin secretion from transplanted islets with a biphasic secretion profile but had no effect on glucagon output. Stimulation of the nerve plexus around the hepatic artery and the portal vein (7.5 Hz, 2 min), which activates primarily the sympathetic system, not only reduced glucose uptake and perfusion flow but also completely reversed the glucose-stimulated increase in insulin secretion. Nerve stimulation did not influence glucagon secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

A portal-arterial glucose concentration gradient as a signal for an insulin-dependent net glucose uptake in perfused rat liver.

Since in the usual perfusion of isolated rat liver via the portal vein an insulin-dependent increase of hepatic glucose uptake could not be demonstrated, the possibility was considered that hepatic glucose uptake might not be a function of the absolute concentration of this substrate but of its concentration gradient between the portal vein and the hepatic artery. Therefore a new method was established for the simultaneous perfusion of isolated rat liver via both the hepatic artery (20-35% flow) and the portal vein (80-65% flow). When glucose was offered in a concentration gradient, 9.5 mM in the portal vein and 6 mM in the hepatic artery, insulin given via both vessels caused a shift from net glucose release to uptake. This insulin-dependent shift was not observed when glucose was offered without a gradient or with an inverse gradient, 6 mM in the portal vein and 9.5 mM in the hepatic artery. Using a portal-arterial glucose gradient as a signal the liver might be able to differentiate between endogenous and exogenous glucose.

Signal propagation via gap junctions, a key step in the regulation of liver metabolism by the sympathetic hepatic nerves.

Cell-to-cell communication via gap junctions has been proposed to be involved in the metabolic actions of sympathetic liver nerves in the rat. The effects of hepatic nerve stimulation and noradrenaline-, PGF2 alpha- and glucagon infusion on glucose metabolism and perfusion flow were studied in perfused rat liver in the absence and presence of the gap junctional inhibitors, heptanol, carbenoxolone and (4 beta)phorbol 12-myristate 13-acetate (4 beta PMA). (i) Stimulation of the hepatic nerve plexus increased glucose output, decreased flow and caused an overflow of noradrenaline into the hepatic vein. (ii) Heptanol completely inhibited not only the nerve stimulation-dependent metabolic and hemodynamic alterations but also the noradrenaline overflow. Thus the heptanol-dependent inhibitions were caused primarily by a strong impairment of transmitter release. (iii) Carbenoxolone inhibited the effects of neurostimulation on glucose metabolism partially by about 50%, whereas it left perfusion flow and noradrenaline overflow essentially unaltered. (iv) 4 beta PMA reduced the nerve stimulation-dependent enhancement of glucose release by about 80% but the noradrenaline-dependent increase in glucose output only by about 30%; the increase in glucose release by PGF2 alpha and by glucagon remained essentially unaltered. 4 beta PMA reduced the nerve stimulation-dependent decrease in portal flow by about 35% but did not affect the noradrenaline-and PGF2 alpha-elicited alterations, nor did it alter noradrenaline overflow. The results allow the conclusion that gap junctional communication plays a major role in the regulation of hepatic carbohydrate metabolism by sympathetic liver nerves, but not by circulating noradrenaline, PGF2 alpha or glucagon.

The p22 phox A640G gene polymorphism but not the C242T gene variation is associated with coronary heart disease in younger individuals.

BACKGROUND: Most recently, evidence has been presented that the NADH/NADPH oxidase p22 phox C242T, but not the A640G gene polymorphism is associated with a reduced risk of coronary artery disease (CAD). METHODS AND RESULTS: We analysed the relationships of both p22 phox gene polymorphisms to CAD in 2205 male Caucasians whose coronary anatomy was defined by means of coronary angiography. In the total population and in high and low risk groups the relative frequencies of the C242T alleles were essentially the same in patients without or with CAD and in individuals without or with myocardial infarction. In contrast, the G allele of the A640G polymorphism was significantly more frequent in subjects without CAD than in patients with CAD (Odds ratio (OR) 0.74 (0.57-0.98); P = 0.038 in multiple logistic regression (MLR)). Correspondingly, the AA genotype of A640G was preferentially found in patients with CAD. These associations did not disappear when the analyses were corrected for multiple comparisons for other gene polymorphisms (ACE I/D gene variation, angiotensinogen T174M and M235T gene polymorphisms, AT1 receptor gene variation, phox C242T gene polymorphism, paraoxonase PON54 and PON191 gene variations) (2p = 0.01 in MLR for the presence of CAD; 2p = 0.039 in multiple regression for the extent of CAD). The association of the A640G gene variation with the presence and extent of CAD was not only identified in the total sample, but was even stronger in various high risk subpopulations of younger individuals (e.g. with hypertension with or without increased apolipoprotein B plasma levels). CONCLUSIONS: Our observations allow the assumption that the p22 phox A640G gene polymorphism is independently associated with the presence and extent of coronary artery disease.

Association of the insertion/deletion gene polymorphism of the apolipoprotein B signal peptide with myocardial infarction.

The Del allele of the apolipoprotein B (apoB) signal peptide (SP) insertion/deletion (Ins/Del) polymorphism has been shown to be associated with elevated plasma levels of apoB, cholesterol and low density lipoprotein. It was the aim of the present study to analyse the relation of this gene variation to the risk of coronary artery disease (CAD) and of myocardial infarction (MI) in a population of 2259 male Caucasians, whose coronary anatomy was defined by means of coronary angiography. ApoB SP DelDel genotypes had significantly higher apoB plasma concentrations than InsIns homozygotes (P = 0.0001) and InsDel heterozygotes (P = 0.002); however, the apoB plasma levels of InsIns and InsDel genotypes were essentially the same (P = 0.54). Similar observations were made with respect to ApoB SP genotype-dependent cholesterol plasma concentrations. Since the apoB plasma level was not only associated with the apoB SP Ins/Del gene variation but also to the extent of coronary artery disease (P <0.0001), individuals with an InsIns genotype and without CAD had the lowest and subjects with a DelDel genotype and triple vessel disease the highest apoB plasma levels (P <0.0001). An association of the apoB SP Ins/Del gene variation with CAD was not detected, neither in the total population nor in low risk groups. In contrast, the gene variation was associated with MI (P <0.05). An Odds ratio of 1.18 (95% CI, 1.01-1.39) associated with the Del allele was detected in the total sample (P <0.02). In a subpopulation of individuals with low plasma triglyceride levels ( <154 mg/dl; mean value) and an DD genotype of the angiotensin I-converting enzyme insertion/deletion gene polymorphism an Odds ratio of 2.01 (1.42-3.05) was calculated (P <0.001). The present study presents evidence for a statistically significant difference in the development of MI between genotype classes of the apoB SP Ins/Del gene polymorphism.

The paraoxonase Leu-Met54 and Gln-Arg191 gene polymorphisms are not associated with the risk of coronary heart disease.

BACKGROUND: Evidence has been presented that gene polymorphisms (PON54 L/M, PON191 Q/R) of paraoxonase are risk factors of coronary heart disease. RESULTS: We determined both PON genotypes in 535 male individuals who were free of vascular disease and in 2249 male subjects who underwent coronary angiography, and analysed the relation of both gene variations to CAD and MI. Both gene polymorphisms were in linkage disequilibrium (P<0.0001). Coronary artery disease: the PON54 gene polymorphism was not associated with an increased risk of CAD. In the total sample and also in younger subjects, an association of the PON191 gene variation with the risk of CAD was not detected when the control group of individuals without coronary heart disease was compared with patients with at least one diseased vessel (verified by coronary angiography). In individuals younger than 62 years, a moderate increase in the relative risk of CAD associated with the PON191 R allele (1.45 (1. 08-1.95); P=0.015) were found, when subjects without vessel disease (verified by coronary angiography) were compared with CAD patients. Myocardial infarction: an association of the PON54 gene variation with MI was not detected when the control group of individuals without coronary heart disease were compared with patients with at least one MI. A marginal increase in the risk of MI associated with the PON54 LL genotype (OR 1.27 (1.05-1.51); P=0.011) were detected when patients without MI but with coronary angiography were compared with MI positive patients. Subgroup analyses of low- and high-risk populations did not reveal any association of both PON gene polymorphisms with CAD or MI. CONCLUSION: The present findings do not strengthen the hypothesis that the paraoxonase gene polymorphisms are independently associated with coronary heart disease indicating that these gene variations are of little usefulness as genetic markers of cardiovascular disease.

The expression of angiotensin-I converting enzyme in human atherosclerotic plaques is not related to the deletion/insertion polymorphism but to the risk of restenosis after coronary interventions.

Plasma and tissue concentrations of the angiotensin-I converting enzyme (ACE) have been shown to be associated with the ACE insertion/deletion (I/D) polymorphism. The purpose of this study was to examine the relation of ACE levels in atherosclerotic plaques to the ACE I/D polymorphism and to restenosis after balloon angioplasty and directional atherectomy (DCA). The study included 104 patients who underwent DCA and received angiographic follow-up at 12 to 18 months. The amount of ACE protein in various morphologically defined plaque components (fibrous, atheromatous, and complicated lesions) of the atherectomy specimens was determined by qualitative and semiquantitative immunohistochemistry. ACE levels were related to the ACE genotype, to plaque morphology and to the risk of restenosis. Sequential staining revealed that pathologic ACE overexpression of the atherosclerotic lesions occurred in intimal smooth muscle cells, fibrocytes/fibroblasts and macrophage/foam cells. The ACE content of the whole plaques and of the single plaque components was not associated with the I/D polymorphism, but with restenosis after coronary interventions. In addition, ACE levels in the atherosclerotic lesions correlated with the severity of vessel wall damage. The ACE phenotype might serve as an indicator for the risk of restenosis after coronary interventions.

Angiotensinogen T174M and M235T gene polymorphisms are associated with the extent of coronary atherosclerosis.

BACKGROUND: The relations of the angiotensinogen (AGT) T174M and M235T gene polymorphisms to the risk of coronary heart disease (CHD) have been investigated in only a few studies with conflicting results. RESULTS: Therefore, we analysed the relationship of the AGT gene polymorphisms to the presence and extent of CHD in 2250 male Caucasians whose coronary anatomy was defined by means of coronary angiography. The relative frequencies of the T and M alleles of the T174M and of the M235T gene variation did not significantly differ between patients without or with single-, double- or triple-vessel disease and between subjects without or with myocardial infarction (MI). In contrast the mean CHD score--defined by Gensini--was higher within MM homozygotes of the T174M gene variation than within TT genotypes; TM subjects had intermediate values. In M235T genotypes, mean CHD scores were similar in the total sample and in older individuals (> or = 62 years), whereas in younger individuals (< 62 years) a higher CHD score was found within AGT 235 T allele carriers than within MM homozygotes. In younger individuals with high apoAI plasma levels, the mean CHD score was clearly higher within TT homozygotes of the M235T gene variation than within MM genotypes; MT subjects had intermediate values. An interaction between both angiotensinogen gene polymorphisms on the extent of CHD or on the risk of non-fatal MI were not observed when the M allele of AGT T174M was combined either with the T allele or the TT genotype of M235T. CONCLUSIONS: The present study strengthens the hypothesis of an association of both angiotensinogen gene polymorphisms with the extent of coronary heart disease.

ACE I/D gene polymorphism: presence of the ACE D allele increases the risk of coronary artery disease in younger individuals.

BACKGROUND: Presence of the D allele or homozygosity for the deletion (D) allele of the ACE insertion/deletion (I/D) polymorphism has been discussed as potent risk factor for coronary artery disease (CAD) and myocardial infarction (MI). METHODS AND RESULTS: In 2267 male Caucasians the relation of the ACE I/D gene polymorphism to CAD and MI were investigated. An association of the D allele to CAD was detected in younger subjects (e.g. < 61.7 years, mean value), but not in older patients (e.g. > or = 61.7 years). Additional exclusion of individuals with other cardiovascular risk factors (e.g. high BMI) produced an even stronger association of the D allele to CAD. In contrast, a relation of this polymorphism to non-fatal MI was only observed in older subjects; additional limitation to individuals without cardiovascular risk factors (e.g. BMI and/or diabetes) yielded a further enhancement of this association to MI. In younger subjects (e.g. < 61.7 years) the gene polymorphism was not related to non-fatal MI even after exclusion of additional risk factors. CONCLUSIONS: The present large case-control study strengthens the assumption of an association of the ACE D allele with the risk of ischemic heart disease.

The impact of the glycoprotein Ia collagen receptor subunit A1648G gene polymorphism on coronary artery disease and acute myocardial infarction.

Platelet glycoprotein (GP) Ia is the major receptor for collagen and plays an important role in platelet adhesion and aggregation. Different gene polymorphisms have been identified that induce either various expression levels (C807T) or alterations of the tertiary structure (A1648G) of GPIa. Previously, we could demonstrate an association of the GPIa C807T dimorphism with nonfatal myocardial infarction. We have now analysed the influence of the GPIa A1648G (Br, HPA-5) dimorphism on the risk of coronary artery disease (CAD) and acute myocardial infarction (AMI). DNA samples from 2163 male Caucasian patients who underwent coronary angiography were genotyped by polymerase chain reaction and restriction fragment length analysis. The relation of the GPIa A1648G dimorphism to the extent of CAD was determined by multiple regression analysis with adjustment for coronary risk factors. Odds ratios (OR) as an estimate of relative risk of CAD and AMI and two-tailed p-values were calculated by multiple logistic regression. In the total study sample, no association was detected between the A1648G dimorphism and CAD or AMI. However, upon analysis of low-risk patient subgroups we found an association of the GPIa A1648G polymorphism with the risk and the extent of CAD (patients with high apoAI/apoB ratio: OR 0.59, p = 0.0090; non- and ex-smokers: OR 0.66, p = 0.0131; both inclusion criteria: OR 0.44, p = 0.0003). The relative frequency of the A1648 allele was higher in controls whereas the GG1648 genotype was overrepresented in patients with CAD. This association was also detectable when individuals with low expression levels of GPIa (C807 homozygotes) were analysed (patients with high apoAI/apoB ratio: OR 0.44, p = 0.0045; non- and ex-smokers: OR 0.61, p = 0.0370). Our findings indicate that the A1648G polymorphism of the platelet collagen receptor plays a role in CAD in well defined patient groups.

The 4G4G genotype of the plasminogen activator inhibitor 4G/5G gene polymorphism is associated with coronary atherosclerosis in patients at high risk for this disease.

BACKGROUND: Disturbances in fibrinolytic activity, such as increase in plasminogen activator inhibitor (PAI) activity, have been linked with an increased risk for coronary artery disease (CAD) and myocardial infarction (MI). Since 4G4G homozygotes of an insertion/deletion (4G/5G) gene variation in the promoter of PAI-I have been shown to have increased levels of PAI-I, we analysed the relation of this gene polymorphism to CAD and MI in a population of 2565 participants who underwent coronary angiography for diagnostic purposes. RESULTS: In the total sample, the PAI-I 4G/4G genotype was associated with the presence, but not with the extent of CAD. However, in a subgroup of former and present smokers (n = 1782) or of individuals with a BMI above the mean value of 26.9 kg x m(-2) (n = 1269), the PAI-I 4G4G genotype was not only associated with the presence, but also with the extent of CAD, defined either by the number of diseased vessels or by the CHD score according to Gensini. This observation also applied to other high-risk groups of individuals with high BMI and hypertension (n = 869), of subjects with high fibrinogen plasma levels (>3.53 g x l(-1), mean value) and hypertension (n = 599) and of former and present smokers with high fibrinogen and hypertension (n = 452). An association of the gene variation with MI was not detected. CONCLUSIONS: The present data indicate that the 4G/4G genotype of the PAI-I gene polymorphism is an independent risk factor for coronary artery disease and that the additional presence of major cardiovascular risk factors accelerates the risk for this disease.

The factor II G20210A and factor V G1691A gene transitions and coronary heart disease.

BACKGROUND: G to A transitions at nucleotide position 20210 of the factor II (Fll) gene and at 1691 of the factor V (FV) gene have been shown to be associated with an increased risk of venous thrombosis. Since it is still unclear whether both gene variations are also related to an increased risk of coronary heart disease (CHD), we studied the relation of both gene variations to coronary artery disease (CAD) and myocardial infarction (MI) in a sample of 2210 male individuals whose coronary anatomy were defined by coronary angiography. RESULTS: In the total sample, the FII G20210A gene variation was not associated with the presence or the extent of CAD, the latter defined either by the degree of vessel disease or by a CHD score according to Gensini. However, individuals with unfavourable lipid profiles showed pronounced differences in CHD scores between GA heterozygotes and GG homozygotes: this observation applied in particular to younger patients (<62 years; mean age of total sample) who simultaneously had low apoAI/apoB ratios (< 1.19, mean value) and high Lp(a) plasma levels (>28 mg/dl; mean value). In addition, in subjects without acetylsalicylic acid treatment GA heterozygotes had clearly higher CHD scores than AA genotypes. Further restriction to smokers, to subjects with high fibrinogen plasma levels (>3.47 g/l; mean value) or to patients with high glucose concentrations (>112 mg/dl; mean value) tended to increase the difference in CHD score between FII G20210A genotypes. An association of the FII G20210A gene variation with non-fatal MI was not observed. In the total sample and in high and low risk subpopulations, an association of the FV G1691A gene variation was not detected neither with presence and extent of CAD or with nonfatal MI. CONCLUSION: The importance of the factor II G20210A gene variation for CHD may be restricted to individuals with major cardiovascular risk factors. In addition, the present study did not strengthen the hypothesis of the factor V G 1691 A transition as a risk factor of coronary heart disease neither in the total sample nor in subgroups of individuals who were at high or low risk of CHD.

Positive association of the beta fibrinogen H1/H2 gene variation to basal fibrinogen levels and to the increase in fibrinogen concentration during acute phase reaction but not to coronary artery disease and myocardial infarction.

BACKGROUND: Fibrinogen has been demonstrated to be an independent risk factor of cardiovascular disease. The absence of the HaeIII cutting site (H2 allele) of an H1/H2 gene variation in the promoter region of the beta fibrinogen gene was associated with increased levels of fibrinogen. METHODS AND RESULTS: In the present study, the effects of the H1/H2 gene variation not only on plasma fibrinogen concentrations but also on coronary artery disease (CAD) and myocardial infarction (MI) were investigated in 923 individuals who underwent coronary angiography for diagnostic purposes. Relation of the H1/H2 genotype to fibrinogen plasma levels: A strong association was observed between the H1/H2 gene variation and fibrinogen levels. The differences in fibrinogen plasma levels between H2H2 and H1H1 homozygotes were almost threefold more pronounced within subjects with clinical chemical signs of an acute phase reaction (CRP > or = 7.5 mg/l) than within a subgroup of subjects without these signs (CRP < 7.5 mg/l) (median of CRP distribution: 7.5 mg/l). In 207 patients who underwent aortocoronary bypass surgery plasma fibrinogen levels were almost identical directly after surgery. Two days after operation fibrinogen increased to clearly higher levels in H2H2 homozygotes than in H1H2 and H1H1 genotypes, whereas almost the same maximal increases in fibrinogen concentrations were reached 3-4 days after surgery in all individuals. Relation of the H1/H2 genotype to CAD and MI. Whereas in the total population the plasma fibrinogen concentrations were strongly associated with smoking, CAD and MI, an association of the H1/H2 gene variation to CAD and MI was not detected. However, mean age at first MI of H2H2 individuals (62.9 years) was clearly higher than of H1H2 genotypes (56.9 years) and of H1H1 subjects (56.4 years). In addition, in a subgroup of individuals with a higher risk of MI by either high apoB and/or low apoA1 plasma levels the portion of MI patients was clearly smaller within H2H2 homozygotes than within H1H2 or H1H1 genotypes, although-also in these high risk groups-mean age at first MI of H2H2 individuals were higher than of the other two genotypes. CONCLUSIONS: Obviously, the H2 allele of the fibrinogen H1/H2 genotype does not only influence basal fibrinogen concentrations, but particularly also the extent of fibrinogen level increase during acute phase reaction. Whereas the fibrinogen plasma level is positively associated with coronary artery disease and myocardial infarction, the H2 allele-although exhibiting an association with elevated fibrinogen levels-was not positively associated with CAD and MI.

Association of the platelet glycoprotein IIIa PlA1/A2 gene polymorphism to coronary artery disease but not to nonfatal myocardial infarction in low risk patients.

BACKGROUND: The platelet membrane glycoprotein IIb/IIIa functions as a receptor for fibrinogen and von Willebrand factor during platelet aggregation. In a small case-control study, evidence has been presented that the PlA2 allele of the platelet glycoprotein GPIIIa PlA/A2 gene polymorphism might be an independent risk factor for acute myocardial infarction (MI). METHODS AND RESULTS: We explored the association of the PlA1A2 to the severity of coronary artery disease (CAD), as assessed angiographically in 2252 male individuals, and to myocardial infarction (MI). The severity of coronary heart disease (CHD) was also estimated by calculating a CHD score according to Gensini. The PlA genotype was determined by allele specific restriction digestion. Relation of the PlA2 allele to CAD: In the total population, the frequency of the PlA2 allele was not associated to the presence or to the extent of CAD. Also the CHD scores of PlA1/PlA2 genotypes were essentially the same. However, after exclusion of individuals with high BMI (> or =26.9 kg/m2) and/or low apoAI (< 1.43 g/l) PlA2PlA2 carriers had clearly higher CHD scores than PlA1PlA1 genotypes: PlA1PlA2 heterozygotes had intermediate values (p <0.05). After division of the study population into one group of individuals without any angiographic signs of CAD (CHD score = 0) and into another group of patients with severe CAD (CHD score (> or = 120), a strong association of the PlA2 allele with severe CAD was also found in the same low risk groups: e.g. exclusion of persons with high BMI and low apoAI resulted in an Odds ratio of 5.37 (1.46-19.7) (p <0.02). Relation of the PlA2 allele to MI: No association was found between PlA1/PlA2 genotypes and risk of MI neither in the total population nor in low risk subgroups. CONCLUSIONS: Whereas no difference in the distribution of allele and genotype frequencies between controls and survivors of MI could be detected, the PlA2 allele is associated with CHD in low risk patients.

Regulation of liver metabolism by the hepatic nerves.

In the isolated rat liver perfused as usual via the portal vein, joint electrical stimulation of the nerve fibers around the artery and the portal vein in the liver hilus increased glucose output, shifted lactate uptake to output, decreased urea and glutamine formation as well as ammonia uptake, reduced ketone body production, lowered oxygen uptake and reduced perfusion flow simultaneously changing the intrahepatic flow distribution; it was accompanied by an overflow of noradrenaline into the hepatic vein. All effects were mediated predominantly via alpha-receptors; they were dependent on extracellular calcium. In livers perfused both via the artery and the portal vein, separate stimulation of the plexus at the common hepatic artery or at the portal vein caused similar effects on glucose and lactate balance and on perfusion flow. Arterial stimulation caused the higher metabolic responses and alterations not only in arterial but also 'transhepaticly' in portal flow, and conversely, portal flow elicited the smaller metabolic responses and alterations in both portal and 'transhepaticly' arterial flow. If sympathetic nerve actions were blocked using alpha- and beta-antagonists, the resulting parasympathetic stimulation increased glucose uptake in the presence of insulin and antagonized the glucagon stimulated glucose release, both alone and more strongly in the presence of insulin. The sympathetic nerves may act directly at the parenchymal cells or indirectly via an overflow of neurotransmitter from the vasculature into the sinusoids or via hemodynamic changes. Experiments with the smooth muscle relaxant sodium nitroprusside and with retrograde flow indicate that neither hemodynamic changes nor noradrenaline overflow from the vasculature can play a major role in the mechanism of action of sympathetic liver nerves on glucose and lactate metabolism. Comparative studies with perfused livers of rats, guinea pigs and tupaias are in line with the view that in the rat the sympathetic nerves act via contacts with only a few periportal hepatocytes, from where the signal is propagated through gap junctions, while in guinea pig and tupaia the nerves act via contacts with almost all parenchymal cells. Sympathetic nerve stimulation of the perfused rat liver caused an increase in the activity of glycogen phosphorylase and a decrease of glycogen synthase, but left the activity of pyruvate kinase unaltered; fructose 2,6-bisphosphate and cAMP were only slightly enhanced.(ABSTRACT TRUNCATED AT 400 WORDS)

Endothelin-1 and vasopressin plasma levels are not associated with the insertion/deletion polymorphism of the human angiotensin I-converting enzyme gene in patients with coronary artery disease.

The objective was to investigate whether the renin-angiotensin (RA) system and related peptides endothelin-1 (ET-1) and vasopressin (VP) influence the development of coronary artery disease (CAD). Angiotensin I-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism has been associated with the risk of CAD. The ACE I/D polymorphism determines ACE activity, but plasma levels of other RA system components remain unchanged. However, ET-1 and VP production could be increased by RA system-dependent stimulation, continually promoted by paracrine stimulation and sustained by neointimal growth. ET-1 and VP have not been associated with the ACE I/D polymorphism so far. The present study investigated the association of the ACE I/D polymorphism with plasma concentrations of ET-1 and VP, as well as with renin, angiotensin-II (AT-II) and ACE activity in 98 Caucasian individuals with CAD. ACE I/D polymorphism showed no association with plasma levels of VP, ET-1, AT-II or renin. These parameters were also not associated taking into consideration different patient variables, such as diabetes mellitus, hypertension or severity of CAD. Only plasma ACE activity was associated with the D allele. In conclusion, the ACE I/D polymorphism could not be related to plasma concentrations of VP, ET-1, renin or AT-II, but as previously demonstrated, it could only be related to ACE activity in patients with CAD. Differences in ACE activity between ACE I/D genotype subgroups are probably compensated within the RA system itself or within non-ACE pathways, so that plasma concentrations of the related peptides ET-1 and VP remain unaffected.