Histological, biochemical and pharmacological characterization of the gastric muscular layer in Chagas disease.

PURPOSE: To assess in vitro the correlation between the number of neurons and the sensitivity to cholinergic drugs and acetylcholinesterase activity in chagasic patients. METHODS: A 3 x 1 cm strip of the muscle layer of the anterior part of the stomach, always close to the angular incisure, was removed from 10 chronic chagasic patients (6 men) submitted to megaesophagus or megacolon surgery and from 10 non-chagasic patients (4 men) submitted to other types of surgery (control group), aged on average 52.3 and 50.1 years, respectively, for histological and pharmacological studies. The action of cholinergic drugs was investigated in isolated preparations according to the superfusion method of Ferreira and Costa, and acetylcholinesterase activity was determined by the method of Ellman. For neuron count, the strips were cut into 8 µm sections according to the method standardized by Alcântara. RESULTS: There was a difference in number of neurons between the chagasic (5,6) and control (7,3) groups. Acetylcholinesterase activity, in moles of hydrolyzed substrate per minute per gram tissue, was reduced in chagasic patients (4,32) compared to the controls (7,30). No hypersensitivity of the gastric musculature to cholinergic drugs was detected, with a reduced maximum response to carbachol and betanechol in the chagasic group. CONCLUSIONS: The reduction of neurons in the myenteric plexus of the stomach of chronic chagasic patients can be demonstrated even in the absence of clinical chagasic gastropathy. The hypersensitivity of the gastric musculature to cholinergic drugs probably depends on intense denervation. The reduced acetylcholinesterase activity demonstrates the involvement of the cholinergic innervation in the stomach of chronic chagasic patients. There was no correlation between number of neurons, sensitivity to cholinergic drugs and acetylcholinesterase activity in the gastric musculature of chagasic and non-chagasic patients.

Histological, biochemical and pharmacologycal characterization of the gastric muscular layer in Chagas disease / Caracterização histológica, bioquímica e farmacológica da musculatura gástrica na doença de Chagas

PURPOSE: To assess in vitro the correlation between the number of neurons and the sensitivity to cholinergic drugs and acetylcholinesterase activity in chagasic patients. METHODS: A 3x1 cm strip of the muscle layer of the anterior part of the stomach, always close to the angular incisure, was removed from 10 chronic chagasic patients (6 men) submitted to megaesophagus or megacolon surgery and from 10 non-chagasic patients (4 men) submitted to other types of surgery (control group), aged on average 52.3 and 50.1 years, respectively, for histological and pharmacological studies. The action of cholinergic drugs was investigated in isolated preparations according to the superfusion method of Ferreira and Costa, and acetylcholinesterase activity was determined by the method of Ellman. For neuron count, the strips were cut into 8 µm sections according to the method standardized by Alcântara. RESULTS: There was a difference in number of neurons between the chagasic (5,6) and control (7,3) groups. Acetylcholinesterase activity, in moles of hydrolyzed substrate per minute per gram tissue, was reduced in chagasic patients (4,32) compared to the controls (7,30). No hypersensitivity of the gastric musculature to cholinergic drugs was detected, with a reduced maximum response to carbachol and betanechol in the chagasic group. CONCLUSIONS: The reduction of neurons in the myenteric plexus of the stomach of chronic chagasic patients can be demonstrated even in the absence of clinical chagasic gastropathy. The hypersensitivity of the gastric musculature to cholinergic drugs probably depends on intense denervation. The reduced acetylcholinesterase activity demonstrates the involvement of the cholinergic innervation in the stomach of chronic chagasic patients. There was no correlation between number of neurons, sensitivity to cholinergic drugs and acetylcholinesterase activity in the gastric musculature of chagasic and non-chagasic patients.

OBJETIVO: Avaliar in vitro a correlação entre o número de neurônios e a sensibilidade a drogas colinérgicas e a atividade da acetilcolinesterase em pacientes chagásicos. MÉTODOS: Em 10 pacientes chagásicos crônicos (6 homens) submetidos à cirurgia de megaesôfago ou de megacólon e em 10 pacientes não chagásicos (4 homens) submetidos a outros tipos de cirurgia (grupo controle), respectivamente com idade média de 52,3 e 50,1 anos, retirou-se uma tira de 3x1 cm da camada muscular da parede anterior do estômago, sempre junto á cisura angular, que serviu para os estudos histológicos e farmacológicos. A ação de drogas colinérgicas foi feita em preparação isolada de acordo com o método de superfusão de Ferreira e Costa, e a determinação da atividade da acetilcolinesterase pelo método de Ellman. Para a contagem de neurônios a tira muscular foi submetida a cortes de 8 micra segundo método padronizado por Alcântara. RESULTADOS: Houve diferença do número de neurônios entre os grupos chagásico (5,6) e controle (7,3). A atividade da acetilcolinesterase mostrou-se diminuída nos chagásicos (4,32) expressa como número de moles do substrato hidrolisado por minuto por grama de tecido, em relação aos controles (7,30). Não se encontrou hipersensibilidade da musculatura gástrica a drogas colinérgicas, encontrando-se inclusive efeito máximo reduzido ao carbacol e betanecol no grupo chagásico. CONCLUSÕES: A redução de neurônios no plexo mioentérico do estômago de pacientes chagásicos crônicos pode ser demonstrada mesmo na ausência de gastropatia chagásica clínica. A hipersensibilidade da musculatura gástrica a drogas colinérgicas provavelmente depende de desnervação intensa. A redução da atividade da acetilcolinesterase demonstra o comprometimento da inervação colinérgica no estômago de pacientes chagásicos crônicos. Não houve correlação entre número de neurônios, sensibilidade a drogas colinérgicas e atividade da acetilcolinesterase na musculatura gástrica de pacientes chagásicos ou não chagásicos.

Caracterizaçäo dos tipos de úlcera gástrica pela acidez gástrica e pela localizaçäo da úlcera / Characterization of gastric ulcer types by gastric acidity and ulcer localization

Duzentos e noventa e dois pacientes com úlcera gástrica foram estudados e as úlceras classificadas de acordo com a localizaçäo no estômago. Cinqüenta por cento dos pacientes estudados apresentaram úlcera no corpo gástrico (tipo I), 27% úlcera gástrica concomitante com úlcera duodenal (tipo II) e 23% úlcera pré-pilórica (tipo III). Em 125 destes pacientes foi avaliada a produçäo máxima de ácido (PMA) em resposta ao estímulo da histamina que foi comparada com a de 140 pacientes com úlcera duodenal e a de 23 controles näo ulcerosos. As úlceras gástricas, tomadas conjuntamente, estiveram associadas à PMA equivalente à do grupo controle, porém com dispersäo muito grande dos valores individuais, sugerindo que aquela populaçäo é constituída por entidades diferentes entre si. A análise de secreçäo gástrica de ácido dos pacientes portadores dos tipos I, II e III de úlcera gástrica (UG), comparada com a dos grupos com úlcera duodenal (UD) e a de controle, sugere o seguinte gradiente teórico para a PMA: UD > = UG + UD = UG pré-pilórica > = C > UG do corpo. As úlceras gástricas dos tipos II e III alinham-se secretoriamente mais com as úlceras duodenais do que com as gástricas do tipo I e, quando com indicaçäo cirúrgica, devem ser tratadas como as úlceras duodenais, com cirurgia que obrigatoriamente inclua vagotomia