Serafim Guimarães

With his colleague Walter Osswald (born 1928) he made the Department of Pharmacology, Medical Faculty of the University of Porto, a center of research on catecholamines and the sympathetic nervous system, especially their relation to blood vessels.

[1] Guimarães was born in Espargo, a village close to the city of Santa Maria da Feira in the Portuguese Região Norte.

He is the second son of the peasant Américo Ferreira Pinto Guimarães and his wife Maria Emília Correia née Pais.

[4] In 1968 he obtained his Ph.D. on the basis of his thesis Receptores Adrenérgicos – Ensaio de Interpretação e Análise (Adrenoceptors – An Attempt at Interpretation and Analysis).

All effects of the catecholamines adrenaline, noradrenaline, dopamine and isoprenaline could be accounted for by an action as agonists, activating substances, on α- und β-adrenoceptors co-existing in vascular smooth muscle.

[10] Guimarães has summarized the knowledge on blood vessels, their nerves and their response to catecholamines in 1983, with Walter Osswald,[11] and in 2001, with his research fellow Daniel Moura.

Metabolizing enzymes, namely monoamine oxidase und catechol-O-methyl transferase (COMT), as well as carrier proteins for the transport through cell membranes contributed to the removal of catecholamines from the extracellular space, thus from the neighbourhood of the receptors, and hence to loss of effect.

[20][21] In 1982, Guimarães wrote in Trends in Pharmacological Sciences:[22] „In vascular tissue there are two different biophases for sympathomimetic agents: one for the α-adrenoceptors around the nerve terminals, where the concentration of the agonist available for the α-effect is mainly governed by uptake into these terminals; one for the β-adrenoceptors in the neighbourhood of COMT whose activity is the main factor determining the concentration of the agonist available for the β-effect.“ Rather than assuming a homogeneous distribution, pharmacologists should reckon with a very inhomogeneous distribution of catecholamines in the extracellular space, low in the immediate neighbourhood of „sites of loss“ such as transporters and enzymes, considerably higher at a distance.

A brief communication of 1981 on presynaptic β-autoreceptors became Guimarães' bibliometrically third-successful paper, and his most successful one reporting original research with new observations.

The authors conclude that the introduction of adrenaline as a false transmitter „revealed the existence of a β-adrenoceptor-mediated positive feedback mechanism in this tissue.“[23] The interest in the discovery stems from the possibility that it explains part of the antihypertensive effect of beta blockers.

Visitors also appreciated what was only loosely connected with the scientific sessions, in 1970 when ″people in Porto still understood by a coffee break a port break″, in 1973 ″Serafim Guimarães' Coimbra fados, the fabulous dinner given by the mayor of Amarante″, in 1989 ″the unanimous wish for scopolamine oder meclizine[30] on the Douro valley serpentine tour.“[1] Guimarães’ supplemented his lectures by co-edition of the textbook Terapêutica Medicamentosa e Suas Bases Farmacológicas (Medicines and their pharmacological basis), which appeared in six editions: Guimarães has also written or co-authored several chapters, such as Sistema adrenérgico.