Resumen

SANCHEZ-LOPEZ, Araceli et al. Role of serotonin receptors in vascular tone in the pithed rat. Arch. Cardiol. Méx. [online]. 2009, vol.79, suppl.2, pp.83-94. ISSN 1665-1731.

Serotonin (5-hydroxytryptamine; 5-HT) has been shown to produce vascular sympatho-inhibition in a wide variety of isolated blood vessels by activation of prejunctional 5-HT₁ receptors. After considering the mechanisms involved in modulating neuroeffector transmission, the present review analyzes the experimental findings identifying the pharmacological profile of the 5-HT receptors that inhibit the sympathetically-induced vasopressor responses in pithed rats. Thus, 5-HT-induced sympatho-inhibition has been shown to be: (i) unaffected by physiological saline or by the selective antagonists ritanserin (5-HT₂), MDL72222 (5-HT₃) or tropisetron (5-HT_3/4); (ii) blocked by methysergide, a non-selective 5-HT_1/2 receptor antagonist; and (iii) potently mimicked by 5-carboxamidotryptamine (5-CT), a non-selective 5-HT₁ receptor agonist, as well as by the selective agonists 8-OH-DPAT (5-HT_1A) indorenate (5-HT_1A), CP93,129 (5-HT_1B), and sumatriptan (5-HT_1B/1D). These findings show the involvement of prejunctional 5-HT₁ receptors. With the use of selective antagonists, it has been shown subsequently that the sympathoinhibition induced by indorenate, CP93,129, and sumatriptan was selectively antagonized by WAY100635 (5-HT1A), cyanopindolol (5-HT_1A/1B), and GR127935 (5-HT_1B/1D), respectively,. These results demonstrate that the 5-HT₁ receptors mediating sympatho-inhibition on the systemic vasculature of pithed rats resemble the pharmacological profile of the 5-HT_1A, 5-HT_1B, and 5-HT₁D subtypes.

Palabras llave : 5-Hydroxytryptamine; prejunctional inhibition; sympathetic outflow; Mexico.