[Role of serotonin receptors in vascular tone in the pithed rat].
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-HT3/4); (ii) blocked by methysergide, a non-selective 5-HT1/2 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-HT1A), indorenate (5-HT1A), CP93,129 (5-HT1B), and sumatriptan (5-HT1B/1D). These findings show the involvement of prejunctional 5-HT1 receptors. With the use of selective antagonists, it has been shown subsequently that the sympatho-inhibition induced by indorenate, CP93, 129, and sumatriptan was selectively antagonized by WAY100635 (5-HT1A), cyanopindolol (5-HT1A/1B), and GR127935 (5-HT1B/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-HT1A, 5-HT1B, and 5-HT1D subtypes.
Sánchez-López
Araceli
A
Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional.
Centurión
David
D
Lozano-Cuenca
Jair
J
Muñoz-Islas
Enriqueta
E
Cobos-Puc
Luis E
LE
Villalón
Carlos M
CM
D000818:Animals; D001808:Blood Vessels / Q000502:physiology*; D003655:Decerebrate State; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology
D011985:Receptors, Serotonin