Reduced urinary glutamate levels are associated with the frequency of migraine attacks in females.

BACKGROUND AND PURPOSE: Recent evidences indicate that glutamatergic homeostasis disorders are implicated in the pathogenesis of migraine. In particular, plasma and cerebrospinal fluid glutamate levels seem to be altered in migraine patients. However, the impacts of glutamate on migraine and especially on aura symptoms, alterations in the frequency of migraine attacks as well as investigations on glutamate on migraine-related metabolic dysfunctions, like hyperinsulinaemia, and an atherogenic lipid profile remain elusive to date. The aim of the present study was to investigate the impact of glutamate on migraine and related metabolic dysfunctions. METHODS: We investigated the urinary glutamate levels of female migraineurs (n = 48) in the interictal phase and healthy controls (n = 48). Parameters of the insulin- and lipid metabolism, inflammatory parameters and anthropometric parameters were additionally determined. RESULTS: Urinary glutamate levels of female migraineurs were significantly decreased with respect to the control group. Logistic regression revealed an odds ratio of 4.04 for migraine. We found a significant correlation with the time-period of patients' last attack and a significant inverse correlation with the annual frequency of migraine attacks. Other parameters of the insulin- and lipid metabolism, anthropometric and inflammatory parameters showed no significant correlation with glutamate levels. CONCLUSION: We show here that female migraineurs exhibit decreased urinary glutamate levels which are associated with a 4.04-fold higher risk for migraine and correlated with patients' frequency of migraine attacks.

Increased matrix metalloproteinase activity is associated with migraine and migraine-related metabolic dysfunctions.

OBJECTIVE: Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are discussed to be involved in the pathophysiology of migraine. Moreover, MMPs may also be involved in migraine-related metabolic alterations like an atherogenic lipid profile and hyperinsulinemia. The aim of this study was to investigate the impact of MMPs and TIMPs on migraine with and without aura and related metabolic dysfunctions. METHODS: MMP activity, six MMPs and three TIMPs, parameters of the insulin and lipid metabolism as well as anthropometric parameters were determined in 124 non-obese subjects. RESULTS: We found highly significant increased MMP activity in migraine patients independent of aura symptoms, which was associated with migraine with an odds ratio of 7.57. Interestingly, none of the determined MMPs and TIMPs showed significant different serum levels between migraine patients and healthy controls. We found significant correlations between MMP activity and parameters of the insulin and lipid metabolism, like Homeostasis Model Assessment index (HOMA index), cholesterol, triglycerides, and oxidized LDL. CONCLUSION: We show here that increased MMP activity is tightly associated with migraine and migraine-related hyperinsulinemia and atherogenic lipid alterations. Our findings represent a new pathophysiological mechanism, which may be of clinical relevance, especially in regard to therapeutic approaches using MMP inhibitors.

Oxidative stress is associated with migraine and migraine-related metabolic risk in females.

BACKGROUND AND PURPOSE: Oxidative stress is discussed to be implicated in the pathophysiology of migraine. However, data are in part controversial and the possible underlying mechanisms remain elusive to date. The aim of this study was to investigate the oxidative stress status of female patients with migraine and its implications on migraine-related metabolic alterations. METHODS: Oxidative stress markers malondialdehyde (MDA), 4-hydroxy-2-nonenal (HNE), carbonylated proteins, parameters of associated nitric oxide stress, inflammation, lipid- and glucose-metabolism were determined in the interictal phase in female patients with migraine and controls. RESULTS: We found significantly increased HNE levels in female migraineurs compared with controls. Logistic regression analyses of HNE revealed an odds ratio for migraine of 4.55. HNE showed significant correlations with the nitric oxide pathway, the insulin- and the lipid-metabolism. CONCLUSIONS: We show here that increased oxidative stress is associated with migraine and contributes to migraine-related metabolic risk like nitrosative stress, an atherogenic lipid profile and hyperinsulinemia. Our data suggest that oxidative stress may represent a key event in the pathophysiology of migraine and a suitable therapeutic target.

Hyperinsulinaemia in migraineurs is associated with nitric oxide stress.

There is growing evidence that alterations in the insulin and glucose metabolism may be involved in the pathogenesis of migraine. Nitric oxide (NO) stress has been associated with migraine. However, the role of NO on the insulin and glucose metabolism in migraineurs has remained elusive to date. The aim of the present study was to investigate the insulin and glucose metabolism in migraineurs and to determine possible interactions with the NO pathway. One hundred and twenty non-obese probands participated in this study, including 48 migraineurs and 72 healthy volunteers. Various parameters of the NO pathway, glucose metabolism as well as body measurement parameters were determined. We found a highly significantly increased insulin and Homeostasis Model Assessment (HOMA)-index in migraine patients, whereas fasting glucose was decreased. Logistic regression revealed an odds ratio of 5.67 for migraine, when comparing the lowest with the highest quartile of HOMA. Multivariate analysis showed that HOMA, waist-to-length ratio and nitrite as parameters of NO stress were highly significantly correlated. We show here that hyperinsulinaemia is associated with migraine and, furthermore, is correlated with increased NO stress. These findings represent a new pathophysiological mechanism that may be of clinical relevance.

Increased nitric oxide stress is associated with migraine.

Nitric oxide (NO) has been implicated in migraine attacks, but the role of NO in migraine remains unclear. We here hypothesize that increased NO in the headache-free period is associated with migraine. One hundred and thirty probands participated in this study. Various parameters of the NO pathway, such as nitrate, nitrite, arginine, citrulline, nitrosylated proteins, asymmetric dimethylarginine, symmetrical dimethylarginine, expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase and two polymorphisms of eNOS were investigated. We found significant increased nitrate and decreased nitrite levels in migraineurs in the headache-free period. Nitrate and nitrite levels showed a significant inverse correlation. Logistic regression revealed an odds ratio of 3.6 for migraine. Other parameters of the NO pathway were neither altered in migraineurs nor correlated with nitrate. We show here that migraine patients suffer under sustained increased nitrosative stress in the headache-free period, which is associated with a 3.6-fold higher risk for migraine.

Lipid profile in normal weight migraineurs - evidence for cardiovascular risk.

BACKGROUND: Recent studies suggest that migraine is associated with metabolic disorders. In particular, migraine may be associated with cardiovascular risk; however, an association of migraine with cardiovascular risk factors like hypercholesterolemia has been proposed, but previous studies have yielded in part conflicting results. The aim of the present study is to evaluate the lipid profile in normal weight migraine patients. METHODS: One hundred thirty-six probands participated in this study. The study group was divided into normal weight migraineurs and control groups, including normal weight controls, obese and overweight controls and migraineurs. Various parameters of the lipid metabolism and inflammatory parameters were investigated. RESULTS: We found significant increased cholesterol, low density lipoprotein cholesterol (LDL-C) and oxidized LDL-C in normal weight migraineurs. Increased oxidized LDL-C was associated with a 7.93-fold increased risk for migraine. Alterations in the lipid profile were not accompanied by increased inflammatory parameters. CONCLUSIONS: We show here that normal weight migraineurs exhibit independent of aura symptoms an atherogenic lipid profile, which shares common features with obesity-related lipid alterations. Our data suggest that migraine is associated with a higher risk for cardiovascular disease and its clinical consequences.

Asymmetric dimethylarginine (ADMA) is tightly correlated with growth in juveniles without correlations to obesity related disorders.

BACKGROUND: Asymmetrical dimethylarginine (ADMA) was found to be increased in conditions associated with atherosclerosis and metabolic disorders. We investigated ADMA in obese juveniles with pre-atherosclerotic symptoms and in normal weight juveniles. DESIGN: To elucidate correlations of ADMA in juveniles with obesity related disorders such as insulin resistance, low grade inflammation, hypertension and pre-atherosclerosis, we analysed ADMA by high performance liquid chromatography (HPLC) in 68 obese and 68 healthy, age and gender matched juveniles. RESULTS: ADMA levels are slightly, but significantly increased (p=0.04) in obese (0.78+/-0.01 micromol/l), compared to normal weight juveniles (0.74+/-0.01 micromol/l). There are no robust correlations of ADMA with obesity related disorders, like dyslipidemia, hypertension, low-grade inflammation and pre-atherosclerosis. Age, body length and alkaline phosphatase, as markers of growth are correlated with ADMA. Multiple testing revealed that, alkaline phosphatase turned out as highly significant positively correlated with ADMA in normal weight (r=0.45/p<0.0001) and obese (r=0.59/p<0.0001) children. CONCLUSIONS: We show here, that ADMA is slightly increased in obese juveniles without any robust correlations to obesity related disorders. ADMA is tightly correlated with alkaline phosphatase as a marker of growth in obese and normal weight, healthy juveniles.

NADH stimulates endogenous dopamine biosynthesis by enhancing the recycling of tetrahydrobiopterin in rat phaeochromocytoma cells.

Treatment of Parkinson patients with L-DOPA (3,4-dihydroxy-L-phenylalanine) leads to endproduct inhibition of tyrosine hydroxylase, the key enzyme in dopamine biosynthesis and the enzyme needing tetrahydrobiopterin and iron as cofactors. To overcome this problem an alternative treatment was investigated which attempted to stimulate endogenous dopamine biosynthesis. Incubation of rat PC 12 cells with NADH (beta-nicotinamide adeninedinucleotide) leads to increased dopamine production. We investigated the possibility that this increase of dopamine biosynthesis was due to stimulation of quinonoid dihydropteridine reductase, the enzyme which recycles the inactive dihydrobiopterin to the active tetrahydrobiopterin. The experiments showed that whereas NADH is able to increase dopamine production in PC 12 cells (rat phaeochromocytoma cells, clone PC 12) up to three-fold, no influence is exerted by NADH on pteridine metabolism; neither are tetrahydrobiopterin concentrations nor the de novo-biosynthesis of pteridines from guanosine triphosphate altered by NADH. Further no influence of NADH on protein de novo synthesis of quinonoid dihydropteridine reductase was observed. However, NADH was able to directly increase the catalytic activity of this enzyme. Our results suggest that the stimulation of dopamine biosynthesis by NADH is due to more rapid regeneration of quinonoid dihydrobiopterin to tetrahydrobiopterin.

Effects of pteridines on chloramine-T-induced growth inhibition in E. coli strains: correlations with molecular structure.

Little is known about the biological significance of most pteridines, despite their ubiquitous occurrence in living cells. Seventeen different pteridines were tested for their ability to modulate the growth inhibitory effect of the disinfectant chloramine-T on three different strains of Escherichia coli bacteria. We found striking differences between the pteridine derivatives: whereas aromatic pterins with a hydroxy function at side chain atom C2' increased the growth inhibition, those with a 7,8-dihydro structure exerted a suppressive effect. These results are in excellent agreement with previously observed effects of pteridine derivatives on chloramine-T-induced luminol-dependent chemiluminescence, and together, are highly suggestive of a general interaction of these compounds with oxygen or chlorine free radicals. This interaction is likely to have biological significance and might offer an explanation for the widespread occurrence of pteridines.

The effect of reduced physical activity on longevity of mice.

Reduced physical activity leads, in female mice, to a reduction of the average and maximal life span. The average age at death of the inactive experimental group was 497 +/- 121 days (mean +/- S.D.) compared to 557 +/- 139 days in the active control group, and the six oldest inactive experimental mice died at age 732 +/- 50 days, while the six oldest active control mice died at 890 +/- 52 days. The restriction of mobility was connected with a higher growth rate and a higher body weight in spite of a significant decrease in food intake. In spite of a reduced food intake leading to a reduced whole body metabolism, the results show that mobility restriction shortens life span in female mice.

Subcutaneous adipose tissue pattern in lean and obese women with polycystic ovary syndrome.

The new optical device, Lipometer, permits the noninvasive, quick, safe, and precise measurement of the thickness of subcutaneous adipose tissue (SAT) layers at any given site of the human body. Fifteen anatomically well-defined body sites from neck to calf describe the SAT topography (SAT-Top) like an individual "fingerprint." SAT-Top was examined in 33 women with polycystic ovary syndrome (PCOS), in 87 age-matched healthy controls and in 20 Type-II diabetic women. SAT-Top differences of these three groups were described, and, based on a hierarchical cluster analysis, two distinctly different groups of PCOS women, a lean (PCOS(L)) and an obese (PCOS(O)) cluster, were found. For visual comparison of the different types of body fat distribution, the 15-dimensional body fat information was condensed to a two-dimensional factor plot by factor analysis. For comparison of the PCOS like body fat distribution with the "healthy" fat pattern, the (previously published) SAT-Top results of 590 healthy women and men (20-70 years old) and 162 healthy girls and boys (7-11 years old) were added to the factor plot. PCOS(O) women showed a SAT-Top pattern very similar to that of women with Type-II diabetes, even though the diabetic women were on average 30 years older. Compared with their healthy controls, SAT-Top of these PCOS(O) patients was strongly skewed into the android direction, providing significantly decreased leg SAT development and significantly higher upper body obesity. Compared with healthy women, PCOS(L) patients had significantly lower total SAT development (even though height, weight, and body mass index did not deviate significantly), showing a slightly lowered amount of body fat in the upper region and a highly significant leg SAT reduction. This type of fat pattern is the same as found in girls and boys before developing their sex specific body fat distribution. We conclude that women with PCOS develop an android SAT-Top, but compared in more detail, we found two typical types of body fat distribution: the "childlike" SAT pattern in lean PCOS patients, and the "diabetic" body fat distribution in obese PCOS women.

Interheavy disulfide bridge in immunoglobulin G (IgG) reacting with dithionitrobenzoate. A unique feature in serum proteins.

Immunoglobulin G (IgG) of many species contains 'labile' disulfide bonds (SS*), which within 24 h undergo a disulfide exchange with dithionitrobenzoic acid (NBSSBN). Aims of the present study were to detect directly this type of SS* groups by means of 14C-labelled NBSSBN, and to investigate its possible presence in other serum proteins. NBSSBN reacts during the first 30 min of incubation with free SH groups, and thereafter with the sulfur atoms of SS* groups. The latter reaction reaches equilibrium after 24 h. The total of thionitrobenzoate residues (NBS) bound to IgG is called 'sigma S' and represents both SH and SS*. The results can be summarized as follows: (1) The measurement of the binding of 14C-NBSSBN gave identical sigma S values with IgG from humans and mice, as compared to the detection with the unlabelled reagent, which is based on the photometric determination of liberated NBS anions; whereas with IgG from rats some differences were observed which were ascribed to different batches of animals investigated; (2) experiments with electrophoretically separated serum proteins revealed only the gamma-globulins strongly binding 14C-NBSSBN in addition to the 30 min reaction, which indicates that SS* is confined to the gamma-globulin fraction; and (3) the significant decrease of sigma S in association with malignant tumors in man and animal models, which was previously described to be due to a specific alteration of the IgG subclass pattern, was likewise detected with the radiometrical method. Previous studies have identified SS* as one of the two inter-heavy disulfide bridges in IgG1, and possible implications of this group in specific functions of IgG1 are discussed.

Free epinephrine in the ischemic blood of muscle transplants in the rabbit.

A stimulated autotransplantation of the rectus femoris muscle in the rabbit was performed by clamping of the blood vessels for 2 h and cutting and suturing of the nerve. Four months after this operation, isometric contractions of the reinnervated muscle were recorded. Comparing controls and postoperation cases, the recovered strength measured about 65%. Due to operation stress, the epinephrine content in plasma was about 420 pg/ml; in plasma of the ischemic muscle it was enhanced to more than 600 pg/ml. During or immediately after ischemia, conjugated epinephrine is assumed to be converted to the free hormone. In systemic blood additionally about 200 pg/ml epinephrine were identified as glucuronides. The activity of adenylate cyclase increased, while the acetylcholine esterase decreased to one-half after nerve cutting.

The influence of noise stress on plasma epinephrine and its binding to plasma protein in the rat.

The influence of a hypersonic noise stress on plasma epinephrine level and on the distribution of i.v. administered radioactive epinephrine between the free and the protein bound form was studied in the rat. The noise stress caused an elevation of epinephrine by 180%. The radioactive hormone was removed more slowly from the vascular compartment of the stressed animals, concomitantly the protein bound fraction increased.

Quantitative characterization of diet effects on glucose tolerance in rabbits.

Normal, atherogenic and butter-enriched diets were given to three groups of rabbits during six months. The effects of the three forms of diet after six months were examined with the intravenous glucose tolerance test, which was evaluated by computer-aided model-fitting and parameter identification. Long-term effects are reflected in parameters such as pancreas sensitivity and the glucose utilization rate constant as a measure of peripheral insulin sensitivity. In these terms, the atherogenic diet caused a diminution of both pancreatic and peripheral sensitivity, whereas the butter-enriched diet led to an increase in glucose utilization and a decrease in pancreatic sensitivity relative to the system parameters of the normally fed control animals. Related to the findings about metabolic regulation are indications for an endocrinological approach to the problems of cholesterogenesis and atheroma formation.

Neural networks as a tool for compact representation of ab initio molecular potential energy surfaces.

Ab initio quantum chemical calculations of molecular properties such as, e.g., torsional potential energies, require massive computational effort even for moderately sized molecules, if basis sets with a reasonable quality are employed. Using ab initio data on conformational properties of the cofactor (6R,1'R,2'S)-5,6,7,8-tetrahydrobiopterin, we demonstrate that error backpropagation networks can be established that efficiently approximate complicated functional relationships such as torsional potential energy surfaces of a flexible molecule. Our pilot simulations suggest that properly trained neural networks might provide an extremely compact storage medium for quantum chemically obtained information. Moreover, they are outstandingly comfortable tools when it comes to making use of the stored information. One possible application is demonstrated, namely, computation of relaxed torsional energy surfaces.

Orthogonal factor coefficient development of subcutaneous adipose tissue topography (SAT-Top) in girls and boys.

The new optical device Lipometer allows noninvasive, quick, and safe determination of the thickness of subcutaneous adipose tissue (SAT) layers (in mm) at any site of the human body. The specification of 15 evenly distributed body sites enables the precise measurement of subcutaneous body fat distribution, so-called subcutaneous adipose tissue topography (SAT-Top). SAT-Top was measured in 980 children aged 7-19 years. In this paper we describe the degree to which SAT-Top body sites are intercorrelated. We consider whether a meaningful reduction of data is possible using factor analysis, which factors can be extracted, and how SAT-Top data of children can be added to a factor value plot, depicting the essential results of age-dependent subcutaneous fat development. SAT layers situated on the same body area provide correlation coefficients up to +r = 0.91. Two factors are extracted: factor 1, containing all upper body sites (from neck to hip); and factor 2, consisting of all leg body sites. When all 980 children are divided into three age groups in a factor value plot, the first age group (7-11 years) shows almost equal SAT-Top development in boys and girls. Afterwards, for the consecutive age groups 2 (11-15 years) and 3 (15-19 years), the age-dependent subcutaneous fat development of boys and girls progresses into nearly orthogonal directions.

Allosteric regulation of neuronal nitric oxide synthase by tetrahydrobiopterin and suppression of auto-damaging superoxide.

The underlying mechanisms regulating the activity of the family of homodimeric nitric oxide synthases (NOSs) and, in particular, the requirement for (6R)-5,6,7,8-tetrahydro-L-biopterin (H(4)Bip) are not fully understood. Here we have investigated possible allosteric and stabilizing effects of H(4)Bip on neuronal NOS (NOS-I) during the conversion of substrate, L-arginine, into L-citrulline and nitric oxide. Indeed, in kinetic studies dual allosteric interactions between L-arginine and H(4)Bip activated recombinant human NOS-I to increase L-arginine turnover. Consistent with this was the observation that H(4)Bip, but not the pterin-based NOS inhibitor 2-amino-4,6-dioxo-3,4,5,6,8,8a,9,10-octahydrooxazolo[1, 2-f]-pteridine (PHS-32), caused an L-arginine-dependent increase in the haem Soret band, indicating an increase in substrate binding to recombinant human NOS-I. Conversely, L-arginine was observed to increase in a concentration-dependent manner H(4)Bip binding to pig brain NOS-I. Secondly, we investigated the stabilization of NOS quaternary structure by H(4)Bip in relation to uncoupled catalysis. Under catalytic assay conditions and in the absence of H(4)Bip, dimeric recombinant human NOS-I dissociated into inactive monomers. Monomerization was related to the uncoupling of reductive oxygen activation, because it was inhibited by both superoxide dismutase and the inhibitor N(omega)-nitro-L-arginine. Importantly, H(4)Bip was found to react chemically with superoxide (O(2)(-.)) and enzyme-bound H(4)Bip was consumed under O(2)(-.)-generating conditions in the absence of substrate. These results suggest that H(4)Bip allosterically activates NOS-I and stabilizes quaternary structure by a novel mechanism involving the direct interception of auto-damaging O(2)(-.).

Android subcutaneous adipose tissue topography in lean and obese women suffering from PCOS: comparison with type 2 diabetic women.

The new optical device, the lipometer, enables the noninvasive, quick, safe, and precise determination of the thickness of subcutaneous adipose tissue (SAT) layers at any given site of the human body. Fifteen anatomically well-defined body sites from neck to calf describe a SAT topography (SAT-Top) like an individual "fingerprint" of a subject. This SAT-Top was examined in 16 women with polycystic ovary syndrome (PCOS) and compared to the body fat distribution of 87 age-matched healthy controls and 20 type-2 diabetic women. SAT-Top differences of these three groups were described and, to render the possibility of visual comparison, the 15-dimensional body fat information was condensed to a two-dimensional factor plot by factor analysis. All PCOS patients had an android body fat distribution with significantly thinner SAT layers on the legs as compared to healthy controls. Moreover, a hierarchical cluster analysis resulted in two distinctly different groups of PCOS women, a lean (PCOSL) and an obese (PCOSO) cluster: compared to healthy women, lean PCOS patients had significantly lower total SAT development, even though height, weight, and body mass index did not deviate significantly. Especially on the legs, their SAT layers were significantly lowered, indicating a more "apple-like" fat distribution type. Obese PCOS women showed a SAT-Top pattern very similar to that of women with type-2 diabetes, although the mean age difference between these groups was more than 30 years. Compared to healthy controls, the SAT-Top of these obese PCOS patients was strongly shifted into the android direction, appearing as "super-apples" with a significantly increased upper trunk obesity to 237.8% and a significantly decreased leg SAT development to 79.8%.

Body fat distribution of overweight females with a history of weight cycling.

Weight cycling may cause a redistribution of body fat to the upper body fat compartments. We investigated the distribution of subcutaneous adipose tissue (SAT) in 30 overweight women with a history of weight-cycling and age-matched controls (167 normal weight and 97 overweight subjects). Measurements of SAT were performed using an optical device, the Lipometer. The SAT topography describes the thicknesses of SAT layers at 15 anatomically well-defined body sites from neck to calf. The overweight women with a history of weight cycling had significantly thicker SAT layers on the upper body compared to the overweight controls, but even thinner SAT layers on their legs than the normal weight women. An android fat pattern was attributed to overweight females and, even more pronounced, to the weight cyclers. The majority of normal weight women showed a gynoid fat pattern. Using stepwise discriminant analysis, 89.0% of all weight cyclers and overweight controls could be classified correctly into the two groups. These findings show the importance of normal weight maintenance as a health-promoting factor.