Assessment of contractility in intact ventricular cardiomyocytes using the dimensionless ‘Frank–Starling Gain’ index

This paper briefly recapitulates the Frank–Starling law of the heart, reviews approaches to establishing diastolic and systolic force–length behaviour in intact isolated cardiomyocytes, and introduces a dimensionless index called ‘Frank–Starling Gain’, calculated as the ratio of slopes of end-systolic and end-diastolic force–length relations. The benefits and limitations of this index are illustrated on the example of regional differences in Guinea pig intact ventricular cardiomyocyte mechanics. Potential applicability of the Frank–Starling Gain for the comparison of cell contractility changes upon stretch will be discussed in the context of intra- and inter-individual variability of cardiomyocyte properties

Phenotypic correlations of fatty acid composition among intramuscular, subcutaneous and intermuscular fat tissues in concentrate-fed beef cattle of differing genotypes

[EN]In an attempt to predict intramuscular fatty acid composition using easily accessible fat depots, between-tissue correlations were studied in 75 Asturiana de los Valles bulls with different levels of muscular hypertrophy, and 25 Asturiana de la Montan˜ a bulls. Trans-18:1 in intramuscular fat was highly and positively correlated with levels in subcutaneous and intermuscular fats, while levels of total n-3 were not correlated. Predicting intramuscular fatty acid composition using easily accessible depots is thus possible for some fatty acids exhibiting high between-tissue correlations (e.g., trans-18:1) but breed and tissue specific deposition may limit this for others (e.g., n-3 fatty acids).[FRE]Dans l’espoir de prédire la composition en acides gras de la graisse intramusculaire àpartir des dépôts de gras aisément accessibles, les auteurs ont examiné les corréations tissulaires chez 75 taureaux Asturiana de los Valles présentant un degré variable d’hypertrophie musculaire et chez 25 taureaux Asturiana de la Montan˜ a. La concentration d’acides gras trans-18:1 dans la graisse intramusculaire est fortement et positivement corrélée à celle observée dans le gras sous-cutané et intermusculaire, alors qu’il n’existe aucune corrélation pour la concentration totale d’acides gras n-3. Il est donc possible de prévoir la composition en acides gras de la graisse intramusculaire à partir des dépôts de gras facilement accessibles pour les acides gras présentant une grande corrélation dans les différents tissus (à savoir, acides gras trans-18:1), mais la race et des dépôts spécifiques à certains tissus pourraient restreindre de telles prévisions pour les autres types d’acides gras (par ex., acides gras n-3)