Electrical Field Stimulation of the Renin Angiotensin Aldosterone System on Uterine Smooth Muscle

Aim of the study. The permanent exchanges between the body and the environment tend to generally disturb homeostasis, particularly the hydroelectrolytic homeostasis. The analysis of the renin-angiotensin system reveals its multiple facets of physiological, physiopathological and pharmacological interest and at the same time highlights the fact that it represents a major component of biomedical scientific research. Material and methods. We studied the renin-angiotensin system action on utero-tubal motility with the help of certain substances that affect its metabolism and the affinity of its receptors. Results 1. Angiotensin II induces a contractile effect dependent on the calcium concentration in the cytosol. 2. In extracellular administration, angiotensin II has an oxytocin effect and an AT1 receptor binding effect. 3. In intracellular administration, the effect of Ang II is completely dependent on the activation of intracellular AT1 receptors. 4. Paradoxically, pretreatment with candesartan does not reduce muscle contractility to electric field stimulation but significantly stimulates it. Electrically stimulated contraction is significantly potentiated by Ang II administration, even under conditions of AT1 receptor blockade with candesartan. Conclusions: There is no mediation of the presence or synthesis of angiotensin II dependent on the presence of the angiotensin converting enzyme. This suggests that the administration of converting enzyme inhibitors in the case of pregnancy associated with hypertension could be without risk, since it does not affect uterine contractility. The physiological consequences of our results need new experimental and clinical studies in order to validate our hypothesis and draw recommendations to be clinically applied.