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Biomedical subjects

R Goutier

Publications and source records attributed to R Goutier.

At least 19 recordsLinked to original sources

Human myeloperoxidase activity is inhibited in vitro by quercetin. Comparison with three related compounds.

Quercetin is an effective inhibitor of human myeloperoxidase (MPO) activity, both with purified enzyme (IC50 = 3.5 microM) and in a system using stimulated human neutrophils. Quercetin is significantly more potent than three other related compounds (rutin, rutin sulfate and troxerutin) and than methimazole, a previously-known myeloperoxidase inhibitor. The inhibitory activity of quercetin is of the competitive type. Moreover, quercetin is directly able to scavenge hypochlorous acid (HOCl), a chlorinated species generated by the MPO/H2O2/Cl- system.

Chemical Phenomena↗

Tocopherol mobilization during intensive exercise.

This work shows that the level of plasma tocopherol (vitamin E) which has free radical scavenging properties rises significantly during intensive exercise. It is proposed that mobilization of tocopherol could help to prevent lipoperoxidation phenomena occurring in exercising skeletal muscle. A hypothetical mechanism relating to a lipolysis effect is discussed to explain this mobilization.

Adult↗

Thromboxane and prostacyclin release in adult respiratory distress syndrome.

Plasma thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) were measured in 84 patients at risk of developing adult respiratory distress syndrome (ARDS) (44 patients following multiple trauma, 29 patients following abdominal surgery and 11 patients with acute pancreatitis). Forty-nine of these 84 patients developed an ARDS. High (greater than 140 pg/ml plasma) TXB2 values were found in 52/84 patients. The median values of TXB2 were: 360 pg/ml in multiple injured, 250 pg/ml in abdominal surgery and 410 pg/ml in acute pancreatitis patients. The median TXB2 value was 575 pg/ml in patients developing ARDS and 140 pg/ml in those without this complication: this difference was statistically significant (p less than 0.05). The median values of 6-keto-PGF1 alpha were 55 pg/ml in multiple injured, 25 pg/ml in abdominal surgery and 120 pg/ml in acute pancreatitis patients. The median 6-keto-PGF1 alpha value was 122 pg/ml in ARDS patients and 25 pg/ml in non-ARDS patients (statistically significant: p less than 0.05). High TXB2 and 6-keto-PGF1 alpha values were particularly related to sepsis in abdominal surgery patients (p less than 0.05) and in multiple injured patients (p less than 0.01). No relation could be established between abnormal TXB2 or 6-keto-PGF1 alpha values and death. High TXB2 values often persisted for several days and were observed particularly at the time ARDS diagnostic criteria were fulfilled.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗

Stimulation of cyclooxygenase by activated human neutrophils is enhanced by uric acid.

Activated human neutrophils supernatant enhances prostanoids production by bull seminal cyclooxygenase (455% of control). Superoxide anion and hydrogen peroxide are not involved in this stimulation, in these experimental conditions. Myeloperoxidase (by its hemic nature) and HPETEs (by their -OOH function) could trigger cyclooxygenase. In the presence of uric acid (10(-3) M), a potent hydroxyl radical scavenger, the cyclooxygenase stimulation by supernatant is increased until 709% of the control.

Animals↗

Trypsin-like activity and thromboxane release in adult respiratory distress syndrome.

Plasmatic immunoreactive trypsin (IRT), thromboxane and trypsin-like enzymatic activity were measured in 117 patients at risk of developing adult respiratory distress syndrome (ARDS) (53 multiple injury, 30 abdominal surgery, 17 acute pancreatitis, 12 burnt and 5 disseminated intravascular coagulation patients). 69 of these patients developed ARDS. Immunoreactive trypsin and thromboxane were measured by radio-immuno-assay and trypsin-like enzymatic activity by spectrophotometry, using a specific chromogenic substrate. Mean IRT value was 675 ng/ml in ARDS and 265 ng/ml in non ARDS patients (p less than 0.05). Mean IRT value was 685 ng/ml in septic and 170 ng/ml in non septic patients (p less than 0.01). An abnormal trypsin-like enzymatic activity was measured in 26 ARDS patients. In 60 patients (37 ARDS and 23 non ARDS), thromboxane appeared in plasma simultaneously or about 24 hours after the beginning of IRT release. The importance of thromboxane release parallels the intensity of IRT. Originating from pancreas, trypsin can appear in plasma either by absorption from gastrointestinal tract or after pancreatic ischemia.

Clinical Enzyme Tests↗

Consumption of pentane by hepatic microsomes and consequences on pentane measurement in exhaled gases.

Pentane measurement in exhaled gases was proposed as a safe method to evaluate the importance of lipoperoxidation in vivo, in man and in animals. However we have observed that pentane, which arises from lipoperoxide decomposition, is significantly consumed by cytochrome P-450-rich liver microsomes. This pentane consumption is completely inhibited after heating the microsomes at 100 degrees C, and is considerably reduced by metyrapone, a cytochrome P-450 inhibitor. Hepatic metabolism of pentane, particularly after cytochrome P-450 induction, constitutes a risk of error, when pentane exhalation is taken as an index of lipoperoxidation in vivo.

Animals↗

[The relation between polyunsaturated fatty acids and cardio-vascular accidents. I. Study of fatty acid components phospholipids].

Blood plasma lipids of women about seventy years old who had suffered from cardiovascular diseases (AVC) were studied and compared with the plasma lipids of women of about the same age without cardiac troubles. A great difference appears in the unesterified fatty acids of the phospholipids from cardiac women: we have observed a decreasing level of polyunsaturated fatty acids with a carbon chain of more than 18 carbons, and a decreasing ratio between the total concentration of the two precursors (linoleic acid omega and alpha-linolenic acid omega 3) and the total concentration of their long chain polyunsaturated derived fatty acids. On the contrary, we did not observe any significant variation of the unesterified fatty acid level in the plasma. The triglyceride and cholesterol levels also were not different between the two groups of patients. The hypothesis of a lack of elongation and of desaturation of linoleic and alpha-linolenic acids by competitive inhibition with oleic acid seems improbable, since the plasmatic concentration of oleic acid was not statistically different.

Aged↗