Detection of dopamine receptor subtypes in the rat diaphragm

BackgroundThe administration of dopamine using an in vivo animal model has been shown to prevent and treat diaphragm fatigue.ObjectiveWith 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.MethodRadioligand binding studies and reverse transcriptase polymerase chain reaction experiments were used.ResultsThe 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 D1-like receptors (D1 and D5 receptors) were detected in the diaphragm.ConclusionsThis 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.