[Stimulation of the central dopaminergic receptor in essential hypertensive patients using amantadine]. / La estimulación del receptor dopaminérgico central en el hipertenso esencial mediante el uso de amantadina.

At present, evidence has been accumulating that point out that some central nervous structures, of oblongata to the limbic system, are primarily involved in the control of systemic arterial pressure (AP). In agreement with several experimental and clinical works, a hypothesis has been suggested that a functional defect of the central dopaminergic system could be involved in the etiopathogenesis of essential hypertension (EH). With the objective of analyzing this hypothesis, the effect of dopamine (DA) agonist, amantadine (Am) on heart rate (HR), AP, plasma catecholamines (CA, PCA), urinary DA, noradrenaline (NA), adrenaline (A), vanilmandelic acid (VMA) and homovanillic acid (HVA), was studied in 19 females with established EH. The study included 2 periods: "placebo" and "drug", each one lasting 22 days, with a register of HR and AP in clino and orthostatism, taken every 3-4 days; at the end of each period, CA and their metabolites were measured. During the drug period, oral Am clorhidrate (300 mg/day, t.i.d.) was administered. With the drug, HR was not change with respect to the placebo period; but the AP in both positions, just as PCA, DA, NA and HVA, showed a highly significant decrease; A and VMA displayed a less significant decrease from the statistical point of view. The obtained results and literature data support the hypothesis that in EH there probably exists a genetic disfunction of the inhibitory central dopaminergic receptor of peripheral sympathetic activity, which is susceptible to compensation by use of several dopaminergic agonists, such as Am.

[Antihypertensive effect of the vasodilator minoxidil combined with dihydrochlorothiazide and propranolol in resistent hypertension]. / Efecto antihipertensivo del vasodilatador minoxidil combinado con dihidroclorotiazida y propranolol en la hipertensión arterial resistente.

The antihipertensive effect of a diuretic (dihidrochlorothiazide 100-200 mgr.), a betablocker (propranolol 20-180 mgr.) and the vasodilating agent minoxidil (25-70 mgr.), administered daily during 10-16 weeks, was asessed in 18 patients with refractory arterial hypertension (RAH). The arterial blood pressure (mm. of Hg.) differences obtained at the end of a 2 weeks diuretic period and at the end of the triple theraphy period was --53.1 +/- 18.1, p less than or equal to 0.001 (mean, standard deviation and significance) and --26.5 +/- 11.8, p less than or equal to 0.001, for clinostatic sistolic and diastolic pressures, respectively and --45.7 +/- 24.1, p less than or equal to 0.001 and --21.6 +/- 40 (p less than or equal to 0.001) for orthostatic sistolic and diastolic pressures, respectively. 66.6% of cases normalized the blood pressure at the end of the protocol. No significant changes were observed in body weight and pulse rate. In 94.4, 66.6 and 16.6% of cases appeared hypertricosis lanuginosa; edema or palpitations, respectively, as theraphy related symptoms. RAH is an entity of poor prognosis and difficult therapheutic management. In this study a significant antihipertensive response was achieved, which was superior to the one obtained in a similar population treated with other regimens in the same clinic. Despite the opposed attitude to continue the treatment exihibited by most female patients, we believe that minoxidil has enriched the therapheutic armamentarium of this dreadfull type of hypertension.