Although epidemiologic research has demonstrated significant differences in incidence and outcomes of sepsis according to sex, their underlying biological mechanisms are poorly understood. Here, we studied the influence of hormonal status by comparing in vivo cardiac performances measured by MRI in non-ovariectomized and ovariectomized septic female rats. Control and ovariectomized rats were randomly allocated to the following groups: sham, sepsis and sepsis plus landiolol. Sepsis was induced by caecum ligation and punction (CLP). Landiolol, a short-acting selective β1-adrenergic blocker improving the in vivo cardiac performance of septic male rats was perfused continuously after sepsis induction. Cardiac MRI was carried out 18 h after induction of sepsis to assess in vivo cardiac function. Capillary permeability was evaluated by Evans Blue administration and measurement of its tissue extravasation. Variation in myocardial gene and protein expression was also assessed by qPCR and western-blot in the left ventricular tissue. Sepsis reduced indexed stroke volume, cardiac index and indexed end-diastolic volume compared to sham group in ovariectomized females whereas it had no effect in control females. This was associated with an overexpression of JAK2 expression and STAT3 phosphorylation on Ser727 site, and an inhibition of the adrenergic pathways in OVR females. Landiolol increased the indexed stroke volume by reversing the indexed end-diastolic volume reduction after sepsis in ovariectomized females, while it decreased indexed stroke volume and cardiac index in control. This was supported by an overexpression of genes involved in calcium influx in OVR females while an inactivation of the β-adrenergic and a calcium efflux pathway was observed in control females. Sepsis decreased in vivo cardiac performances in ovariectomized females but not in control females, presumably associated with a more pronounced inflammation, inhibition of the adrenergic pathway and calcium efflux defects. Administration of landiolol prevents this cardiac dysfunction in ovariectomized females with a probable activation of calcium influx, while it has deleterious effects in control females in which calcium efflux pathways were down-regulated.

Les auteurs insistent sur les points suivants: toute infection rebelle des urines chez l’enfant, toute protéinurie doit conduire à la pratique d’une urographie. Des anomalies mêmes légères de la morphologie des calices et de l’uretère pelvien doivent faire soupçonner un reflux, et demander une cystographie retrograde. La mise en evidence d’un reflux passif et mictionnel chez l’enfant doit faire poser une indication opératoire, à condition que le reflux persiste à 2 examens successifs et en dehors d’une cystite evolutive. Le traitement chirurgical du reflux doit être effectué si possible avant l’âge de 5 ans. La technique de Leadbetter leur donne toute satisfaction et elle leur paraît résoudre le problème technique du traitement des reflux vésico-urétéraux. II est inutile d’effectuer une operation anti-reflux chez un malade en état d’insuffisance rénale, avec une azotémie au-dessus de 1 g, et une clearance de Γurée au-dessous de 20 ml.

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