Individual distribution of muscle hypertrophy among hamstring muscle heads: Adding muscle volume where you need is not so simple.

PURPOSE: The aim of this study was to determine whether a 9-week resistance training program based on high load (HL) versus low load combined with blood flow restriction (LL-BFR) induced a similar (i) distribution of muscle hypertrophy among hamstring heads (semimembranosus, SM; semitendinosus, ST; and biceps femoris long head, BF) and (ii) magnitude of tendon hypertrophy of ST, using a parallel randomized controlled trial. METHODS: A total of 45 participants were randomly allocated to one of three groups: HL, LL-BFR, and control (CON). Both HL and LL-BFR performed a 9-week resistance training program composed of seated leg curl and stiff-leg deadlift exercises. Freehand 3D ultrasound was used to assess the changes in muscle and tendon volume. RESULTS: The increase in ST volume was greater in HL (26.5 ± 25.5%) compared to CON (p = 0.004). No difference was found between CON and LL-BFR for the ST muscle volume (p = 0.627). The change in SM muscle volume was greater for LL-BFR (21.6 ± 27.8%) compared to CON (p = 0.025). No difference was found between HL and CON for the SM muscle volume (p = 0.178).There was no change in BF muscle volume in LL-BFR (14.0 ± 16.5%; p = 0.436) compared to CON group. No difference was found between HL and CON for the BF muscle volume (p = 1.0). Regarding ST tendon volume, we did not report an effect of training regimens (p = 0.411). CONCLUSION: These results provide evidence that the HL program induced a selective hypertrophy of the ST while LL-BFR induced hypertrophy of SM. The magnitude of the selective hypertrophy observed within each group varied greatly between individuals. This finding suggests that it is very difficult to early determine the location of the hypertrophy among a muscle group.

[Blockade of nitrogen oxide and nitrites by various substances]. / Etude du blocage de l'oxyde azotique et du nitrite par divers corps.

The laws by which a number of substances fix nitrogen oxide and sodium nitrite were studied. Nitrogen oxide leads to the formation of compounds of the N O X type, characterised by the following equilibrium constants: 1.93 X 10(-2) for sodium ascorbate, 1.96 X 10(-2) for cysteine, 2.79 X 10(-2) for guanidine, 1.43 X 10(-3) for glutathion, 0.384 for sarcosin, 4.6 X 10(-2) for galacturonic acid, and 1.8 X 10(-3) for neuraminic acid. Mucic, benzoic, lactic and gallic acid do not fix this oxide, nor do glycerol and imidazole. Of all the substances listed above, only ascorbate and cysteine fix nitrite. It was not possible to establish any direct fixing law. This fact, taken with the conditions of the medium, leads to the conclusion that nitrite is fixed only after reduction, in the form of nitrogen oxide NO, according to the laws referred to above.

[Effect of various blockers of nitrite and nitrogen oxide on the formation of nitrosamines]. / Influence de quelques bloquants du nitrite et de l'oxyde azotique sur la production de nitrosamines.

The effects of galacturonic, gallic, acetylneuraminic acid, ascorbate, cysteine, glutathion and imidazole on the formation of dimethylnitrosamine and diethylnitrosamine was studied in a simple aqueous medium with four different nitrite contents (50, 100, 500 and 1 000 ppm) and the two amines, compared with control samples. The nitrosamines were determined by the TELLING method (confirmed by photolysis). The results observed were compared with the laws of fixing nitrite in the form of nitrogen oxide, studied previously. For sarcosin and imidazole, the fixing takes into account the phenomena observed. The other substances lead to a conclusion that there are two stages in the process: 1) fixing of the nitrite to a greater or lesser degree in the form of a nitrogen oxide complex, 2) direct effect on the nitrosation reaction which is catalysed or slowed down. The discussion based on the literature, concludes that the final nitrosation reaction give rise to free radicals, even in an aqueous medium.

[Determination of nitrates and nitrites in animal products]. / Dosage des nitrates et des nitrites dans les produits animaux.

Meat is a complex medium in which nitrates and nitrites react by processes which are not well known. We do not know how to determine the quantities added, and estimating the residual doses depends on the analytic techniques studied. The analysis begins with extractions and purifications by various techniques described. A brief description is then given of 13 techniques for determining nitrites, 5 of which were applied successfully to meat products, and 18 techniques for determining nitrates, 12 of them suitable for meats. The references are given. The authors conclude by stressing the need for better knowledge of the effect of extraction and preparation techniques in order to give meaning to the results obtained.

[Preservation of vitamin B1 and B2 during the preparation of pork meat]. / Devenir des vitamines B1 et B2 dans la fabrication des charcuteries.

Thiamin and riboflavin seem to resist fairly well to the proceedings of meat products studied here (cooked hams, patties, dry sausages). This result is normal enough to riboflavin, it is less for thiamin which sensitive to nitrite and to heating is well established by the literature. The origin of these observed phenomenons of protection is probably due to the complexation of these vitamins by the meat proteins. A similar phenomenon has been seen before by several authors on milk proteins, eggs and specially sulfhydril groups. This complexation is confirmed by the important release of both vitamins we noted during processing. They are determined much more easily on processed meat products than on raw materials. The nutritional repercussion of the observed phenomenon is difficult to estimate accurately. The vitamins release we find out, make them more available for the organism but it would be compared to the enzymatic decomplexation which occurs in vivo, during digestion, that we did not studied. Nevertheless such an approach would be necessary for the estimation of the practical value of the analytical determinations generally used.

[State of nitrite in meat products]. / Etudes sur l'état du nitrite dans les produits de viandes.

The authors search the form under which nitrite is in cured products. Nitrate formation found by official methods is not confirmed by qualitative characterization. The calculations, according to the chemical equations, show the total breakdown of nitrite in nitroge oxide: NO, bound by many substances which are in meats. The distillation experiments confirm the calculations, the characteristic photometric spectra get in sulfitic medium and the modified Zambelli's reaction. These results lead to estimate that both technologic and toxicologic actions impute to nitrite is dominated by the idea of NO more or less bound, according to the medium composition.