RESUMO
Dopamine (DA) is a free radical scavenger that attenuates apoptosis. We studied the effects of normal saline (NS) and DA on diaphragm apoptotic protein expression following 60 min of inspiratory resistance loading in rats. We tested for 27 apoptotic-related proteins and found 12 in the diaphragm. Of the 12 proteins, superoxide dismutase copper zinc (SOD [CuZn]) and proprioceptive event related potential (PERP) were significantly higher in the DA group than in the NS and sham groups (p = .002, p = .007). DA group diaphragms had significantly greater expression of SOD (CuZn) than the NS (p = .005) and sham group diaphragms (p = .003). Likewise, the DA group had significantly greater expression of PERP than the NS group (p = .008). These results suggest that DA decreases diaphragm apoptosis through elevated expression of SOD (CuZn). The identification of 12 apoptotic-related proteins will assist investigators as they study diaphragm apoptosis.
Assuntos
Apoptose/efeitos dos fármacos , Diafragma , Dopamina/uso terapêutico , Sequestradores de Radicais Livres/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Insuficiência Respiratória/prevenção & controle , Doença Aguda , Análise de Variância , Animais , Diafragma/química , Diafragma/efeitos dos fármacos , Modelos Animais de Doenças , Dopamina/farmacologia , Avaliação Pré-Clínica de Medicamentos , Sequestradores de Radicais Livres/farmacologia , Inalação/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley , Insuficiência Respiratória/etiologia , Superóxido Dismutase/análiseRESUMO
BACKGROUND: The administration of dopamine using an in vivo animal model has been shown to prevent and treat diaphragm fatigue. OBJECTIVE: With the knowledge that dopamine stimulates alpha- and beta-adrenergic and dopamine receptors, the purpose of this study was to investigate whether dopamine receptors are present in the diaphragm. In addition, if dopamine receptors were detected, we would identify the class and subtype of dopamine receptors. METHOD: Radioligand binding studies and reverse transcriptase polymerase chain reaction experiments were used. RESULTS: The receptor binding studies were unable to establish whether dopamine receptors were present in the diaphragm. However, highly sensitive reverse transcriptase polymerase chain reaction experiments demonstrated that D(1)-like receptors (D(1) and D(5) receptors) were detected in the diaphragm. CONCLUSIONS: This study is the first to report the class and specific subtype of dopamine receptors found in the diaphragm. By identifying dopamine receptors in the diaphragm, we have a better understanding of the mechanisms by which dopamine treats and prevents diaphragm fatigue.
Assuntos
Diafragma/metabolismo , Expressão Gênica , RNA/genética , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Animais , Diafragma/citologia , Masculino , Contração Muscular , Fadiga Muscular/fisiologia , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Advances in science have increased the knowledge of how cells die in the body (apoptosis). A basic understanding of this process can improve nurses' ability to review new scientific literature and enable them to provide safer bedside care.
