Mental stress may induce myocardial ischemia and ventricular arrhythmia in patients with coronary artery disease, and cholinergic stimulation is a potential protective mechanism. The purpose of this study was to determine the effect of pyridostigmine bromide (PYR), a reversible cholinesterase inhibitor, on the cardiac responses to a mental stress challenge. Twelve healthy young volunteers were submitted to a mental stress test (arithmetic test) 2 hours after the oral administration of either placebo or PYR (45 mg) on two separate days, following a randomized crossover double-blind protocol. Heart rate was reduced after both placebo and PYR (p < 0.05), but the cardiac responses to the mental stress were lower with PYR (p < 0.05): mean RR interval (mean +/- SE)-placebo: 730 +/- 19 msec; PYR: 769 +/- 21 msec; Peak systolic pressure-placebo: 129 +/- 4 mmHg; PYR: 124 +/- 3 mmHg; Peak diastolic pressure-placebo: 92 +/- 3 mmHg; PYR: 89 +/- 4 mmHg; Mean rate-pressure product-placebo: 10,496 +/- 412 bpm x mmHg; PYR: 9,746 +/- 383 bpm x mmHg. In conclusion, 45 mg of pyridostigmine blunted the pressor and chronotropic responses to mental stress in healthy young subjects.

Supporting the observations that motivate the study, our findings indicate blunted sympathetic reactivity and exacerbated vagal response to feeding in H. pylori-positive patients.

O hipertireoidismo está associado a uma fraqueza muscular generalizada que é parte da manifestação clínica inicial de cerca de 80% dos pacientes. A recuperação da performance muscular esquelética durante o tratamento do hipertireoidismo depende tanto do aumento da massa muscular quanto da melhoria da função intrínseca da musculatura esquelética. Por outro lado, o treinamento contra resistência aumenta a força e a endurance muscular em diferentes grupos de indivíduos. O objetivo do presente trabalho foi avaliar o efeito deste tipo de treinamento sobre a recuperação da função muscular esquelética de pacientes portadores de hipertireoidismo. Os pacientes, atendidos no ambulatório de endocrinologia, diagnosticados clínica e laboratorialmente com doença de Graves, foram submetidos, antes do tratamento e quatro meses após, a medidas antropométricas e testes de força máxima e endurance musculares (sustentando 30% da carga máxima) de quatro movimentos [handgrip esquerdo (HE) e direito (HD), legpress (LEG), flexão plantar de tornozelo (FPT) e supino reto (SR)]. Após a avaliação inicial, os pacientes foram divididos em dois grupos: 1) controle (GC - tratamento medicamentoso) e 2) treinamento (GT - acrescentado treinamento contra resistência individualizado 2X/semana). Os resultados (GC, n = 3; GT, n = 4; todas do sexo feminino) mostram: <img src="/img/revistas/rbme/v7n1/a04tab01.gif"> Os autores concluem que o treinamento contra resistência parece favorecer aumento da massa e da performance muscular esquelética em pacientes com hipertireoidismo.

Skeletal Muscle Dysfunction and Body Composition in Hyperthyroidism.The purpose of this article is to review aspects of skeletal muscle dysfunction and body composition in hyperthyroidism. Hyperthyroidism is associated with general muscle weakness, which is part of the initial clinical manifestation of about 80% of patients, compromising their daily activities and quality of life. A factor that contributes for strength reduction is muscle atrophy, which usually tends to affect proximal muscle groups. In addition, hyperthyroidism is accompanied by weight loss due to consumption of muscle mass and adipose tissue. Studies have demonstrated that medical treatment is able to promote recovery of strength and slowly, endurance, defined as the capacity to sustain sub-maximal loads for prolonged periods, and that resistance training associated with medical treatment leads to a major gain of muscular strength and resistance in those patients. Although a standard body composition during weight recovery after treatment is not established, patients submitted to strength training show weight recovery associated mainly with muscle mass gain. (Arq Bras Endocrinol Metab 2002;46/6:626-631) Keywords: Hyperthyroidism; Skeletal muscle function; Body composition O HIPERTIREOIDISMOPORDOENÇADEG RAVESé a doença autoimune mais prevalente nos Estados Unidos (1) e acarreta alterações somáti -cas e metabólicas generalizadas. O estudo das alterações na função muscurevisão

Pyridostigmine, at a dose of 45mg, decreases heart rate at rest and during exercise, with minimal side effects and without interfering with exercise tolerance and ventilation variables.