RESUMO
PURPOSE: This study aims to compare the physiology of the longitudinal muscle of the anal canal with the internal anal sphincter in pigs. METHODS: Histology and in vitro studies were performed to compare the effect of neural responses induced by electric stimulation and through nicotinic, purinergic, and serotoninergic receptors. RESULTS: The longitudinal muscle and the internal anal sphincter are constituted exclusively by smooth muscle. Strips from the internal anal sphincter a) developed myogenic tone; b) responded to electric stimulation with an "on" relaxation antagonized by nitric oxide synthase inhibitors and purinergic P2Y1 antagonists, and with an "off" contraction antagonized by atropine and phentolamine; and c) responded to stimulation of nicotinic receptors with a relaxation antagonized by nitrergic and purinergic P2Y1 antagonists, responded to stimulation of serotoninergic 5-hydroxytryptamine 3 receptors with a contraction, and relaxed to carbachol and purinergic P2X agonists. Strips from the longitudinal muscle a) did not develop tone, b) responded to electric stimulation with an "on" contraction antagonized by atropine, and c) did not respond to stimulation of nicotinic or serotoninergic 5-hydroxytryptamine 3 receptors, and carbachol and purinergic P2X agonists induced a contraction. CONCLUSIONS: The motility of the internal anal sphincter includes myogenic tone, relaxation mediated by nitric oxide and purinergic P2Y1 receptors, and contraction mediated by cholinergic motor neurons and sympathetic fibers. The motility of the longitudinal muscle is limited to a contraction mediated by cholinergic neurons, suggesting that longitudinal muscle contracts during relaxation of the internal sphincter, shortening the anal canal. Nicotinic, muscarinic, and serotoninergic receptors might be therapeutic targets for anal motor disorders.
Assuntos
Canal Anal/fisiologia , Músculo Liso/fisiologia , Difosfato de Adenosina/análogos & derivados , Difosfato de Adenosina/farmacologia , Canal Anal/efeitos dos fármacos , Canal Anal/inervação , Análise de Variância , Animais , Atropina/farmacologia , Carbacol/farmacologia , Estimulação Elétrica , Masculino , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/fisiologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/inervação , Óxido Nítrico Sintase/antagonistas & inibidores , Nitroprussiato/farmacologia , Fentolamina/farmacologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/fisiologia , Receptores Nicotínicos/efeitos dos fármacos , Receptores Nicotínicos/fisiologia , Receptores de Serotonina/efeitos dos fármacos , Receptores de Serotonina/fisiologia , Suínos , Tionucleotídeos/farmacologiaRESUMO
Primary gynecologic myeloid sarcomas are rare, and their diagnosis is often difficult. Differential diagnosis includes lymphomas and carcinomas of the gynecologic tract. We report the clinical, morphological, immunohistochemical and cytogenetic features of two cases of chloromas of the female genital tract, which progressed to acute myeloid leukemia in spite of aggressive therapy.
