Disfunción Tiroidea Subclínica / Subclinical thyroid disfunction

El desarrollo de Técnicas más económicas para la determinación de la tirotropina hipofisaria (TSH) y de las hormonas tiroideas (T3 Ft4) ha permitido su utilización en el ámbito de la Atención Primaria, incrementándose de forma notable a este nivel el diagnóstico de difusión tiroidea subclínica (cifras alteradas de TSH con niveles normales de fT) (AU)

Study of the in vivo and in vitro cardiovascular effects of four new analogues of ketanserin: implication of 5-HT2A and alpha1 adrenergic antagonism in their hypotensive effect.

The in vivo and in vitro cardiovascular effects of the novel 5-HT2A/alpha1/H1 antagonist ketanserin analogues QF 0303B, QF 0307B, QF 0311B, QF 0313B were studied in anaesthetized normotensive rats (ANR) and in isolated rubbed rat aorta (IRRA). In ANR, 0.2 mg x kg(-1) i.v. of each compound produced a rapid, remarkable but short-lasting fall in mean arterial blood pressure (MAP) accompanied by bradycardia. All compounds significantly modified the pressor effects induced by 5-hydroxytryptamine (5-HT) and noradrenaline (NA). In IRRA, the compounds inhibited NA- and 5-HT-induced contractions in a competitive fashion. Furthermore, the analogues displayed lower H1-antagonist activity than ketanserin. Compounds tested showed low 5-HT2B affinity and no activity at muscarinic, nicotinic, or 5-HT3 receptors, nor any marked ability to produce smooth muscle relaxation via calcium entry blockade. There is a significant correlation between hypotension reached and inhibition of the 5-HT-induced pressor responses (but not for NA). A certain degree of correlation was observed between hypotensive effect endurance vs. alpha1-adrenoceptor blockade (but not for serotonin). These results indicate that in this series the brief hypotensive activity in ANR is attributed to a 5-HT1A receptor blockade and the duration of the effect is better attributed to an alpha1 adrenoceptor blockade.