Associations of phase angle with platelet-activating factor metabolism and related dietary factors in healthy volunteers

IntroductionPhase angle (PA) is derived from bioelectrical impedance analysis (BIA). It reflects cell membrane function and decreases in disease. It is affected by inflammation, oxidative stress, and diet. Platelet-activating factor (PAF) is a potent inflammatory lipid mediator. Its levels, along with the activity of its metabolic enzymes, including CDP-choline:1-alkyl-2-acetyl-sn-glycerol-cholinephosphotransferase, acetyl-CoA:lyso-PAF-acetyltransferases, and PAF-AH/Lp-PLA2 are also related to dietary factors, such as the dietary antioxidant capacity (DAC). The aim of the study was to estimate whether the PAF metabolic circuit and related dietary factors are associated with PA in healthy volunteers.MethodsIn healthy subjects, PAF, its metabolic enzyme activity, and erythrocyte fatty acids were measured, while desaturases were estimated. Food-frequency questionnaires and recalls were used, and food groups, macronutrient intake, MedDietScore, and DAC were assessed. Lifestyle and biochemical variables were collected. DXA and BIA measurements were performed.ResultsLp-PLA2 activity was positively associated with PA (rho = 0.651, p < 0.001, total population; rho = 0.780, p < 0.001, women), while PAF levels were negatively associated with PA only in men (partial rho = −0.627, p = 0.012) and inversely related to DAC. Estimated desaturase 6 was inversely associated with PA (rho = −0.404, p = 0.01, total sample). Moreover, the DAC correlated positively with PA (rho = 0.513, p = 0.03, women). All correlations were adjusted for age, body mass index, and sex (if applicable).ConclusionPA is associated with PAF levels and Lp-PLA2 activity in a gender-dependent fashion, indicating the involvement of PAF in cell membrane impairment. The relationship of PA with DAC suggests a protective effect of antioxidants on cellular health, considering that antioxidants may inhibit PAF generation

Characterization of the De Novo Biosynthetic Enzyme of Platelet Activating Factor, DDT-Insensitive Cholinephosphotransferase, of Human Mesangial Cells

Platelet activating factor (PAF), a potent inflammatory mediator, is implicated in several proinflammatory/inflammatory diseases such as glomerulonephritis, glomerulosclerosis, atherosclerosis, cancer, allergy, and diabetes. PAF can be produced by several renal cells under appropriate stimuli and it is thought to be implicated in renal diseases. The aim of this study is the characterization of DTT-insensitive cholinephosphotransferase (PAF-CPT) of human mesangial cell (HMC), the main regulatory enzyme of PAF de novo biosynthetic pathway. Microsomal fractions of mesangial cells were isolated and enzymatic activity and kinetic parameters were determined by TLC and in vitro biological test in rabbit washed platelets. The effect of bovine serum albumin (BSA), dithiothreitol (DTT), divalent cations (Mg2+ and Ca2+), EDTA, and various chemicals on the activity of PAF-CPT of HMC was also studied. Moreover, preliminary in vitro tests have been performed with several anti-inflammatory factors such as drugs (simvastatin, IFNa, rupatadine, tinzaparin, and salicylic acid) and bioactive compounds of Mediterranean diet (resveratrol and lipids of olive oil, olive pomace, sea bass “Dicentrarchus labrax,” and gilthead sea bream “Sparus aurata”). The results indicated that the above compounds can influence PAF-CPT activity of HMC

Lipoprotein-associated phospholipase A2 (Lp-PLA2) activity, platelet-activating factor acetylhydrolase (PAF-AH) in leukocytes and body composition in healthy adults

<p>Abstract</p> <p>Background</p> <p>Lipoprotein-associated phospholipase A₂(Lp-PLA₂) also known as serum platelet activating factor acetylhydrolase (PAF-AH) activity constitutes a novel risk marker for cardiovascular disease. Leukocytes constitute one main cellular source of circulating Lp-PLA₂. The aim of the present study was to evaluate the association of both serum and leukocyte PAF-AH activities with fat distribution and lean tissue. One hundred healthy volunteers without cardiovascular disease history participated in this study (n = 52 men, 44 ± 13 years and n = 48 women, 43 ± 13 years). Body composition was assessed with dual-energy X-ray absorptiometry, while anthropometrical indices were also measured. The activity of Lp-PLA₂and levels of lipid and glycemic parameters were determined in fasting samples.</p> <p>Results</p> <p>Mean Lp-PLA₂activity was 24.8 ± 4.5 and 19.6 ± 5.0 nmol/min/mL in men and women, respectively (P < 0.001). Mean activity of PAF-AH in leukocyte homogenates was 386 ± 127 pmol/min/mg and 292 ± 92 pmol/min/mg in men and women, correspondingly (P < 0.001). In multiple regression models upper and total adiposity measures were positively associated with Lp-PLA₂activity in men after adjusting for LDL-cholesterol, age, smoking, hs-CRP and physical activity, whereas no associations were found with PAF-AH leukocyte homogenates activity. Hierarchical analysis revealed that the variables with the highest explanatory ability of Lp-PLA₂activity in men, were DXA deriving L1–L4 region of interest and arms fat (increase in R²= 0.136, P = 0.005 and increase in R²= 0.118, P = 0.009, respectively), followed by trunk fat and total fat. In women, no association of body composition variables with Lp-PLA₂nor PAF-AH leukocyte homogenates activity was found.</p> <p>Conclusion</p> <p>Lp-PLA₂activity is differentiated across levels of adiposity and topology of adipose tissue, whereas no association was found regarding PAF-AH leukocyte homogenates activity. Our findings suggest that Lp-PLA₂may compensate for the adiposity-associated increases in inflammatory and oxidative burden, in men.</p

Effect of differently fed farmed gilthead sea bream consumption on platelet aggregation and circulating haemostatic markers among apparently healthy adults:A double-blind randomized crossover trial

Fish consumption beneficially affects coagulation markers. Few dietary intervention studies have investigated differently fed farmed fish against these cardio-metabolic risk factors in humans. This double-blind randomized crossover trial evaluated differently fed farmed gilthead sea bream consumption against platelet aggregation and circulating haemostatic markers among apparently healthy adults. Subjects aged 30–65 years, with a body mass index 24.0–31.0 kg/m2, consuming less than 150 g cooked fish per week, were recruited in Attica, Greece. Participants were randomized (n = 38, 1:1) to one of two sequences; consumption of fish fed with fish oil diet (conventional fish, CF)/fish fed with olive pomace-enriched diet (enriched fish, EF) versus EF/CF. The primary outcomes were ex vivo human platelet aggregation and circulating plasminogen activator inhibitor-1 (PAI-1) and P-selectin (sP-selectin) concentrations. EF consumption had no significant effect on platelet sensitivity or haemostatic markers compared to CF. Platelet sensitivity to platelet-activating factor (PAF) decreased after CF consumption during the second period (p p < 0.01 for both). Based on current findings, consumption of enriched farmed gilthead sea bream had no greater effect on coagulation markers in adults compared to the conventionally fed fish

The associations between dairy product consumption and biomarkers of inflammation, adipocytokines, and oxidative stress in children: a cross-sectional study

The association between dairy product consumption and biomarkers of inflammation, adipocytokines, and oxidative stress is poorly studied in children. Therefore, these associations were examined in a representative subsample of 1338 schoolchildren with a mean age of 11.5 (±0.7) years in the Healthy Growth Study. Information on dairy product consumption was collected by dietary recalls. Total dairy consumption was calculated by summing the intake of milk, yogurt, and cheese. Inflammatory markers, i.e., high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and adipocytokines, i.e., leptin, adiponectin, and the antioxidant enzyme glutathione peroxidase (GPx) were analysed. Due to the skewed distribution hs-CRP, IL-6, and leptin were log transformed. Multivariable regression analyses adjusted for age, sex, energy intake, physical activity, parental education, Tanner stage, and fat mass were used to assess the associations between consumption of total dairy, milk, yogurt, cheese, and markers of inflammation, adipocytokines, oxidative stress, and adiponectin−leptin ratio. Our results showed that milk consumption was inversely associated with leptin (β: −0.101; 95% CI: −0.177, −0.025, p = 0.009) and positively associated with the adiponectin−leptin ratio (β: 0.116; 95% CI: 0.020, 0.211; p = 0.018), while total dairy, cheese, and yogurt consumption were not associated with inflammatory, adipocytokine, or antioxidant markers. Further prospective studies are needed to confirm these results

Study on the metabolism of platelet activating factor (PAF) in human kidney and its participation to the pathogenesis of glomerulonephritis

Platelet Activating Factor, PAF, a glyceryl-ether phospholipid, is one of the most potent mediators of the allergic and inflammatory reactions. It is biosynthesized by either the de novo biosynthesis of glyceryl ether lipids or by remodelling of membrane phospholipids. Degradation of PAF proceeds via cleavage of the acetyl group from the sn-2 position yielding the biologically inactive lyso-PAF. PAF is synthesized and catabolized by various renal cells and tissues and exerts a wide range of biological activities on kidney tissue suggesting a potential role for him during renal injury. The aim of this study was to identify whether cortex and medulla of human kidney contains the PAF biosynthetic activities of the rem AT and de novo AT as well as the degradative activity of AH. Cortex and medulla were obtained from nephrectomized patients with adenocarcinoma. The enzymatic activities were determined by chemical methods developed in our laboratory. Both acetyltransferase activities were detected in cortex and medulla and distributed among the membrane subcellular fractions. rem AT and de novo AT show optimal rates at pH values of 7,4-7,7 and 8,4, respectively. rem AT is inhibited by BSA at concentration over 0,5 mg/ml, it follows Michaelis-Menten kinetics with both its substrates, lyso-PAF and Acetyl-CoA, it prefers to act on substrates with an ether ether rather than ester bond at the sn-1 position and its activity depends on the availability of Ca2+ ions. Α -SH group is necessary for its activity. The enzyme is strongly inhibited by various detergents but we managed to solubilize 28% of it using glycerol as the detergent. De novo AT activity is independent of Ca2+ but it depends on the presence of -S-S- groups at its active center. It shows optimal rates at BSA concentration of 0,5 mg/ml. AAPA, which is the product of the de novo AT action, is rapidly hydrolyzed to alkylacetylglycerol by phosphohydrolases. The different biochemical characteristics of rem AT and de novo AT suggest that they are discrete enzymes. There is no statistical difference between the specific activities of rem AT/de novo AT of cortex and medulla. AH is distributed between cytosol and membranes. There is no difference between the biochemical properties of cytosolic and membranous forms of AH. Finally, a novel method for the homogenization of renal biopsies was developed in order to determine the activity of both rem AT and AH at the homogenate.Ο Παράγοντας Ενεργοποίησης Αιμοπεταλίων, PAF είναι ένα γλυκεριναιθερικό φωσφολιποειδές και αποτελεί έναν από τους ισχυρότερους μεσολαβητές της αλλεργικής και φλεγμονώδους αντίδρασης. Η βιοσύνθεσή του μπορεί να γίνει, είτε με την de novo βιοσύνθεση των γλυκεριναιθέρων, είτε με την μετατροπή πρόδρομων μεμβρανικών φωσφολιποειδών μέσω της πορείας αναχηματισμού. H αποικοδόμηση του PAF ξεκινά με την υδρόλυση της ακετυλομάδας από την sn-2 θέση του γλυκερινικού σκελετού που οδηγεί στον ανενεργό λυσο-PAF. Η παραγωγή αλλά και η αποικοδόμηση PAF έχει παρατηρηθεί τόσο σε απομονωμένο νεφρικό ιστό όσο και σε νεφρικά κύτταρα πειραματόζωων. Ο παραγόμενος στο νεφρό PAF έχει πλήθος βιολογικών δράσεων και ενοχοποιείται ως ένας από τους μεσολαβητές της νεφρικής βλάβης. Σκοπός της εργασίας αυτής είναι η ταυτόχρονη αναζήτηση και μελέτη των βιοσυνθετικών ενζύμων του PAF, de novo AT και rem AT καθώς και του αποικοδομητικού του ενζύμου, PAF-AH σε ανθρώπινο νεφρικό ιστό (φλοιό και μυελό). Οι νεφρικοί ιστοί προήλθαν από νεφρεκτομηθέντες ασθενείς με νεοπλασματική νεφρική διεργασία και τα ένζυμα προσδιορίστηκαν με χημικές μεθόδους που αναπτύχθηκαν στο εργαστήριο. Διαπιστώθηκε ενζυμική δραστικότητα rem AT και de novo AT τόσο σε φλοιό όσο και σε μυελό ανθρώπινου νεφρικού ιστού όπως πιστοποιήθηκε και από ανάλυση των προϊόντων των ενζυμικών δοκιμασιών. Οι rem AT και de novo AT είναι μεμβρανικά ένζυμα. To βέλτιστο pH δράσης της μικροσωμιακής rem AT είναι στην περιοχή 7,4-7,7, ενώ της de novo AT είναι 8,4. Η rem AT αναστέλλεται από συγκεντρώσεις BSA μεγαλύτερες των 0,5 mg/ml, ακολουθεί κινητική Michaelis-Menten με υποστρώματα τον λυσο-PAF και το ακέτυλο-CoA, δείχνει εξειδίκευση για αιθερικά υποστρώματα, εξαρτάται από Ca2+,ενώ πειράματα με διάφορους αναστολείς έδειξαν ότι για την δράση της απαιτεί μια ή περισσότερες ομάδες -SH. Το ένζυμο αναστέλλεται ισχυρά από διάφορους γαλακτωματοποιητές αλλά επιτεύχθηκε μικρό ποσοστό διαλυτοποίησης του ενζύμου (28 %) με κατεργασία με γλυκερόλη. H de novo AT είναι ανεξάρτητη Ca2+, απαιτεί ομάδες -S-S- για την δράση της και δείχνει μέγιστη δραστικότητα σε συγκέντρωση BSA 0,5 mg/ml. To προϊόν της δράσης της, το ΑΑΡΑ, υδρολύεται ταχύτατα από φωσφοϋδρολάσες προς AAG. Τα παραπάνω βιοχημικά χαρακτηριστικά διαφοροποιούν τις δύο ενζυμικές δραστικότητες. Δεν φαίνεται να υπάρχει στατιστικώς σημαντική διαφορά στην ειδική δραστικότητα της rem AT/de novo AT φλοιού και μυελού. Η δραστικότητα της PAF-AH κατανέμεται στο κυτόπλασμα και τις μεμβράνες αλλά δεν φαίνεται να υπάρχει διαφορά στις ιδιότητες της μεμβρανικής και κυτοπλασματικής PAF-AH. Τέλος, αναπτύχθηκε μέθοδος ομογενοποίησης νεφρικών βιοψιών για τον προσδιορισμό της δραστικότητας rem AT και PAF-AH σε αυτές και προσδιορίστηκε η δραστικότητα των ενζύμων στις πρώτες βιοψίες

Effect of Pre-Season Training on Physiological and Biochemical Indices in Basketball Players&mdash;A Systematic Review

The pre-season period in basketball includes all the physiological attributes that the players need to work on and develop, in order to sustain a full season workload. The monitoring of the effectiveness of pre-season training is based on a variety of biochemical and physiological indices; however, it is still unclear how pre-season training affects those markers. Therefore, this study aimed to analyze the effects of pre-season training on biochemical and physiological markers. A search was performed in five large scientific databases (Pubmed (Medline), Scopus, Science-Direct, Sport-Discus (EBSCO), Semantic Scholar) and produced 7081 results, which after removing duplicates and applying inclusion and exclusion criteria, resulted in 28 published scientific articles being included in this review. The most important findings suggested that the majority of the studies used a 6- or an 8-week pre-season training protocol, because these protocols have shown significant positive effects over the years. In addition, the plyometric training protocols that were used by many studies have been found to be beneficial for basketball athletes for many physiological parameters. Furthermore, the evaluation of biochemical markers can be a very useful tool in monitoring and managing fatigue, which is an essential part of modifying the training process, in order to maximize performance

Effect of a 6-Week Preseason Training Protocol on Physiological and Muscle Damage Markers in High-Level Female and Male Basketball Players

This study aimed to investigate the effects of a 6-week preseason functional and plyometric fitness training protocol, on physiological and biochemical markers of performance and exercise-induced muscle damage, and to compare the response of these markers between high-level female and male basketball players. The sample of the study consisted of 19 professional athletes (10 male; 9 female) competing in two different teams. The examined markers were body mass, BMI, fat percentage, speed, acceleration, explosiveness, vertical jumping ability, creatine kinase (CK) and lactate dehydrogenase (LDH). The preseason training period improved speed, acceleration, explosiveness and vertical jumping ability (~1–8%) and led to significant fat percentage reductions in both groups equivalently. CK and LDH increased similarly in both groups, and the percentage increases were higher for CK compared to LDH. Further investigation and a larger sample size are required in order to determine an approach that is more capable of maximizing performance without causing any possible injuries that may be related to muscle damage