IQUIMEFA   05518
INSTITUTO QUIMICA Y METABOLISMO DEL FARMACO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
THYROID DESEASE: CARDIOVASCULAR NITRIC OXIDE TO HYPOVOLEMIA
Autor/es:
NATALIA OGONOWSKI, GISSELLE PIRO, DÉBORAH PESSAH, NOELIA ARRECHE, BERNARDITA PUCHULU, ANA M BALASZCZUK, ANDREA FELLET
Reunión:
Congreso; LXI Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC).; 2016
Resumen:
9e previously demonstrated that activation of nitric oxide 01pathYay is involved in the restoration of vascular volume andblood pressure folloYing bleeding. Cardiovascular function is influencedby the autonomic nervous system and numerous endocrinehormones in Yhich thyroid hormones have relevance. Additionally,a functional relation involving thyroid hormones, endothelial cellsand 01 has been extensively described in the past several years.This study aimed to investigate Yhether 01 participates in thecardiovascular function and haemodynamic adaptation to acutehaemorrhage in animals Yith thyroid disorders. Sprague&aYley ratsaged months old treated Yith T hyper, µg/ g body Yeightor . methimazole hypo, Y/v during days Yere pretreatedYith 0) nitrolarginine methyl ester L0A/E and submitted to blood loss. Heart function Yas evaluated by echocardiography./easurements of arterial blood pressure, heart rate, nitric oxidesynthase activity and protein levels Yere performed. Hypothyroidanimals had decreased fractional shortening and ejection fractionand increased left ventricle internal diameter. HoYever, hyperthyroidrats had decreased ventricle diameter and no changes in cardiaccontractility. Haemorrhage elicited a hypotension of similar magnitudeYithin min. Then, this parameter Yas stabilized at aboutŌ min and maintained until finalized, min. L0A/E rats.shoYed that the immediate hypotension Yould be independent ofnitric oxide. 0itric oxide synthase inhibition blunted the changes ofheart rate induced by blood loss. Animals Yith thyroid disorder hadloYer atrial enzyme activity associated Yith a decreased enzymeisoform in hypothyroid group. +n ventricle, thyroid abnormalities Yereassociated Yith higher enzyme activity, Yhich Yas not correlatedYith changes in protein levels. Haemorrhage induced an increasedheart nitric oxide production. 9e concluded that thyroid disordersYere associated Yith hypertrophic remodelling Yhich impacted differentlyon cardiac function and its adaptation to a hypovolemia.Hypovolemia triggered a nitric oxide synthase activation modulatingthe heart function to maintain haemodynamic homeostasis.This involvement depends on a specific enzyme isoform, cardiacchamber and thyroid state.