Biomedical subjects

V Mougios

Publications and source records attributed to V Mougios.

24 records · Page 2Linked to original sources

PubMed1994

Pancreatic lipase assays with triglycerides as substrate: contribution of each sequential reaction to product formation.

Human pancreatic lipase assays are usually performed in the presence of either emulsified triglycerides or diglycerides within the limits of their solubility. Two reactions are catalyzed in the presence of triglycerides: hydrolysis of triglycerides to diglycerides, and diglycerides to monoglycerides. The contribution of each reaction to the final result was determined after extensive kinetic studies on the appearance and/(or) accumulation of intermediates and/(or) products. Acylated glycerides were analyzed after extraction from the reaction mixture, separation of lipid classes by thin-layer chromatography, and quantification by capillary gas chromatography. The results show that after 10 min of reaction in the presence of high concentrations of triolein, 75% of the released fatty acids arise from the first reaction. Relative merits and disadvantages of each substrate (triglyceride or diglyceride) are discussed in terms of practicability.

Acylation↗

PubMed1993

Plasma TSH, T3, T4 and cortisol responses to swimming at varying water temperatures.

The acute effect of 30-min swimming at a moderate speed, at three water temperatures (20, 26 and 32 degrees C) on plasma thyroid stimulating hormone (TSH), free thyroxine (F.T4), triiodothyronine (T3) and cortisol concentrations was studied in 15 élite male swimmers. Blood was sampled before and immediately after the events. The heart rate, which was continuously monitored during exercise, had the highest response at 32 degrees C and the lowest at 20 degrees C. Blood lactate concentrations were found to be similar after the three tests. Plasma TSH and F.T4 were found to be significantly increased (by 90.4% and 45.7% respectively) after swimming at 20 degrees C, decreased at 32 degrees C (by 22.3% and 10.1% respectively) and unchanged at 26 degrees C. Exercise at these three water temperatures did not significantly affect T3. Finally, plasma cortisol was found to be increased after swimming at 32 degrees C (by 82.8%) and 26 degrees C (by 46.9%), but decreased at 20 degrees C (by 6.1%).

Adolescent↗

PubMed1993

Effect of water temperature on performance, lactate production and heart rate at swimming of maximal and submaximal intensity.

The effect of water temperature on performance effort, monitored heart rate and lactate production during freestyle swimming at maximal and submaximal speed has been studied. Fifteen male sprint swimmers performing 100 m swimming and fifteen comparable endurance competitors performing 30 min swimming at submaximal speed served as subjects. Water temperature in separate events was 20, 26 and 32 degrees C. At maximal performance there was a direct relationship between any two of the following parameters: water temperature, average swimming speed, heart rate during the competition and plasma lactate concentration after the event. Thus, the best effort (speed 1.704 m/s), the highest peak heart rate (185 beats/min) and the highest lactate level (19.8 mmol/l) were observed at 32 degrees C (all mean values). In contrast, these values were markedly lower at 20 degrees C. At the submaximal effort, water temperature was related to peak heart rate only. The highest peak heart rate (144 beats/min) was again obtained at 32 degrees C, while the lactate concentration (4.2-5.2 mmol/l) was independent of temperature. Water temperature appears to have a direct effect on performance effort, heart rate and lactate production during swimming at maximal intensity, whereas this effect seems to fade at submaximal efforts.

Adolescent↗

PubMed1986

Isoforms of the phosphorylatable myosin light chain in arterial smooth muscle.

Two isoforms of the phosphorylatable myosin light chain of arterial smooth muscle have been identified, at proportions of 15 and 85%. The isoforms have similar tryptic peptide maps and can be mono-, di- and triphosphorylated. In intact or homogenized muscle, monophosphorylation and, to a small degree, diphosphorylation occur, whereas in isolated actomyosin diphosphorylation and triphosphorylation are manifested. Serine and threonine residues are phosphorylated in all three systems, but the ratio of phosphothreonine to phosphoserine is much higher in actomyosin than in muscle.

Animals↗

PubMed1986

Characterization of the phosphorylatable myosin light chain in rat uterus.

The 20 kDa myosin light chain of 32P-labeled rat uterus exhibited four spots on two-dimensional gel electrophoretograms; the corresponding autoradiograms revealed that three spots were radioactive. Completely dephosphorylated light chain exhibited three spots on electrophoretograms. Serine and threonine residues of the light chain were found to be phosphorylated in the uterus at a ratio of 6 to 1. During contraction, the amount of each phosphoamino acid increased proportionally to the increase in the total phosphate content of the light chain.

Animals↗

PubMed1985

Stretch-induced myosin light chain phosphorylation and stretch-release-induced tension development in arterial smooth muscle.

Stretching arteries from resting length to 1.7 times the resting length increased myosin light chain phosphorylation from 40 to 70% in a graded fashion, reaching a plateau at 1.6 times the resting length. When the fully stretched arteries were released, active tension developed without any exogenous stimulating agent. This stretch-release-induced tension approached the same magnitude as that of the control K+-induced tension. Stretch-induced phosphorylation and the subsequent tension development upon release of stretch were prevented by incubating the arteries in physiological salt solutions containing ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) or chlorpromazine. The inhibition produced by EGTA was reversible. Stretch-induced phosphorylation decreased as a function of time, regardless of whether stretch was maintained, or slackened slowly, or released quickly. While tension developed upon release of stretch, light chain phosphorylation simultaneously decreased. As tension reached and maintained its maximal value, phosphorylation continued to decrease. Thus, light chain phosphorylation is necessary for activation of arterial muscle contraction, but it need not be maintained during tension development or maintenance.

Animals↗