61 research outputs found
Valeric Acid, a Gut Microbiota Product, Penetrates to the Eye and Lowers Intraocular Pressure in Rats
Glaucoma patients have an increased level of trimethylamine, a toxic product of gut bacteria, in the aqueous humor: a pilot study
Plasma Trimethylamine-N-oxide following Cessation of L-carnitine Supplementation in Healthy Aged Women.
L-carnitine supplementation elevates plasma trimethylamine-N-oxide (TMAO), which may participate in atherosclerosis development by affecting cholesterol metabolism. The aim of the current study was to determine the effect of increased plasma TMAO on biochemical markers in the blood following cessation of L-carnitine supplementation. The follow-up measurements were performed on subjects who completed 24 weeks of L-carnitine or placebo supplementation protocol. Blood samples were taken after finishing the supplementation and then 4 and 12 months following the supplementation withdrawal. Four months after cessation of L-carnitine supplementation, plasma TMAO concentration reached a normal level which was stable for the following eight months. During this period, no modifications in serum lipid profile and circulating leukocyte count were noted. TMAO implications in health and disease is widely discussed. The results of this study demonstrate no adverse effects of elevated plasma TMAO, induced by L-carnitine, on the measured parameters at 4 and 12 months after withdrawal of supplementation
Heart Failure Disturbs Gut–Blood Barrier and Increases Plasma Trimethylamine, a Toxic Bacterial Metabolite
Trimethylamine (TMA) is a gut bacteria product oxidized by the liver to trimethylamine-N-oxide (TMAO). Clinical evidence suggests that cardiovascular disease is associated with increased plasma TMAO. However, little headway has been made in understanding this relationship on a mechanistic and molecular level. We investigated the mechanisms affecting plasma levels of TMAO in Spontaneously Hypertensive Heart Failure (SHHF) rats. Healthy Wistar Kyoto (WKY) and SHHF rats underwent metabolic, hemodynamic, histopathological and biochemical measurements, including tight junction proteins analysis. Stool, plasma and urine samples were evaluated for TMA and TMAO using ultra performance liquid chromatography-mass spectrometry. SHHF presented disturbances of the gut–blood barrier including reduced intestinal blood flow, decreased thickness of the colonic mucosa and alterations in tight junctions, such as claudin 1 and 3, and zonula occludens-1. This was associated with significantly higher plasma levels of TMA and TMAO and increased gut-to-blood penetration of TMA in SHHF compared to WKY. There was no difference in kidney function or liver oxidation of TMA to TMAO between WKY and SHHF. In conclusion, increased plasma TMAO in heart failure rats results from a perturbed gut–blood barrier and increased gut-to-blood passage of TMAO precursor, i.e., TMA. Increased gut-to-blood penetration of bacterial metabolites may be a marker and a mediator of cardiovascular pathology
The Potential Role of SCFAs in Modulating Cardiometabolic Risk by Interacting with Adiposity Parameters and Diet
An In Vivo Method for Evaluating the Gut-Blood Barrier and Liver Metabolism of Microbiota Products.
Total testosterone to dihydrotestosterone ratio assessed by LC-MS/MS predicts a worse metabolic profile not only in PCOS patients
Objectives:
Total testosterone/dihydrotestosterone ratio (TT/DHT) was found to determine metabolic risk in polycystic ovary syndrome (PCOS). The aim of this study was to analyze whether (TT/DHT) may be helpful in predicting metabolic risk not only in PCOS patients but also in healthy women.
Material and methods:
Total testosterone (TT), dihydrotestosterone (DHT), androstendione and dehydroepiandrosterone sulphate (DHEA-S) were measured by LC-MS/MS in 36 women with PCOS and in 29 age-matched controls without clinical hyperandrogenism. In all participants, anthropometric data, lipids, adipose tissue percent (%fat), HOMA-IR were also assessed.
Results:
The studied groups were not different in terms of age, BMI, waist circumference, %fat and HOMA-IR. In the patients group, mean TT and androstendione levels were significantly higher as compared to controls (1.4 nmol/L vs. 1.0 nmol/L, P < 0.001) and (6.6 nmol/L vs. 4.9 nmol/L, P < 0.01), respectively. In the patients group, mean TT/DHT ratio was significantly higher compared to controls (3.6 vs. 2.7, P < 0.01) and correlated with BMI (r = 0.37, P < 0.05), waist circumference (r = 0.44, P < 0.01), %fat (r = 0.30, P < 0.05), as well as with insulin levels (r = 0.38, P < 0.05) and HOMA-IR (r = 0.44, P < 0.05). The association between TT/DHT ratio and unfavorable metabolic parameters was also seen in controls.
Conclusion:
Total testosterone/dihydrotestosterone ratio assessed by LC-MS/MS correlates with a worse metabolic profile not only in PCOS patients, but also in healthy women
Low Content of Cyclosporine A and Its Metabolites in the Colostrum of Post-Transplant Mothers
The rate of post-transplant mothers who breastfeed while on immunosuppression is progressively increasing. Data on breastfeeding while on cyclosporine-based regimens are limited. Therefore, we assessed the amount of cyclosporine and its metabolites that might be ingested by a breastfed infant by measuring the concentration of cyclosporine and its metabolites in the colostrum of seven post-transplant mothers. The mean concentration of cyclosporine in the colostrum was 22.40 ± 9.43 mcg/L, and the estimated mean daily dose of the drug was 1049.22 ± 397.41 ng/kg/24 h. Only three metabolites (AM1, DHCsA, and THCsA) had mean colostrum amounts comparable to or higher than cyclosporine itself, with the daily doses being 468.51 ± 80.37, 2757.79 ± 1926.11, and 1044.76 ± 948.56 ng/kg/24 h, respectively. Our results indicate a low transfer of cyclosporine and its metabolites into the colostrum in the first two days postpartum and confirm the emerging change to the policy on breastfeeding among post-transplant mothers. A full assessment of the safety of immunosuppressant exposure via breastmilk will require further studies with long-term follow-ups of breastfed children
Total testosterone to dihydrotestosterone ratio assessed by LC-MS/MS predicts a worse metabolic profile not only in PCOS patients
Objectives: Total testosterone/dihydrotestosterone ratio (TT/DHT) was found to determine metabolic risk in polycystic ovary syndrome (PCOS). The aim of this study was to analyze whether (TT/DHT) may be helpful in predicting metabolic risk not only in PCOS patients but also in healthy women.
Material and methods: Total testosterone (TT), dihydrotestosterone (DHT), androstendione and dehydroepiandrosterone sulphate (DHEA-S) were measured by LC-MS/MS in 36 women with PCOS and in 29 age-matched controls without clinical hyperandrogenism. In all participants, anthropometric data, lipids, adipose tissue percent (%fat), HOMA-IR were also assessed.
Results: The studied groups were not different in terms of age, BMI, waist circumference, %fat and HOMA-IR. In the patients group, mean TT and androstendione levels were significantly higher as compared to controls (1.4 nmol/L vs. 1.0 nmol/L, P < 0.001) and (6.6 nmol/L vs. 4.9 nmol/L, P < 0.01), respectively. In the patients group, mean TT/DHT ratio was significantly higher compared to controls (3.6 vs. 2.7, P < 0.01) and correlated with BMI (r = 0.37, P < 0.05), waist circumference (r = 0.44, P < 0.01), %fat (r = 0.30, P < 0.05), as well as with insulin levels (r = 0.38, P < 0.05) and HOMA-IR (r = 0.44, P < 0.05). The association between TT/DHT ratio and unfavorable metabolic parameters was also seen in controls.
Conclusion: Total testosterone/dihydrotestosterone ratio assessed by LC-MS/MS correlates with a worse metabolic profile not only in PCOS patients, but also in healthy women
Trimethylamine, a gut bacteria metabolite and air pollutant, increases blood pressure and markers of kidney damage including proteinuria and KIM-1 in rats
BACKGROUND: Trimethylamine oxide (TMAO) is a biomarker in cardiovascular and renal diseases. TMAO originates from the oxidation of trimethylamine (TMA), a product of gut microbiota and manufacturing industries-derived pollutant, by flavin monooxygenases (FMOs). The effect of chronic exposure to TMA on cardiovascular and renal systems is undetermined. METHODS: Metabolic, hemodynamic, echocardiographic, biochemical and histopathological evaluations were performed in 12-week-old male SPRD rats receiving water (controls) or TMA (200 or 500 µM/day) in water for 18 weeks. TMA and TMAO levels, the expression of FMOs and renin-angiotensin system (RAS) genes were evaluated in various tissues. RESULTS: In comparison to controls, rats receiving high dose of TMA had significantly increased arterial systolic blood pressure (126.3 ± 11.4 vs 151.2 ± 19.9 mmHg; P = 0.01), urine protein to creatinine ratio (1.6 (1.5; 2.8) vs 3.4 (3.3; 4.2); P = 0.01), urine KIM-1 levels (2338.3 ± 732.0 vs. 3519.0 ± 953.0 pg/mL; P = 0.01), and hypertrophy of the tunica media of arteries and arterioles (36.61 ± 0.15 vs 45.05 ± 2.90 µm, P = 0.001 and 18.44 ± 0.62 vs 23.79 ± 2.60 µm, P = 0.006; respectively). Mild degeneration of renal bodies with glomerulosclerosis was also observed. There was no significant difference between the three groups in body weight, water-electrolyte balance, echocardiographic parameters and RAS expression. TMA groups had marginally increased 24 h TMA urine excretion, whereas serum levels and 24 h TMAO urine excretion were increased up to 24-fold, and significantly increased TMAO levels in the liver, kidneys and heart. TMA groups had lower FMOs expression in the kidneys. CONCLUSIONS: Chronic exposure to TMA increases blood pressure and increases markers of kidney damage, including proteinuria and KIM-1. TMA is rapidly oxidized to TMAO in rats, which may limit the toxic effects of TMA on other organs. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12967-022-03687-y
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