Detection of dopamine receptor subtypes in the rat diaphragm.
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.


METHODS
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.
Pierce
Janet D
JD
School of Nursing, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
Jegathesan
Jay
J
Levant
Beth
B
Winter
Michelle
M
McCarson
Kenneth E
KE
Clancy
Richard L
RL
D000818:Animals; D003964:Diaphragm / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D008297:Male; D009119:Muscle Contraction; D018763:Muscle Fatigue / Q000502:physiology; D012313:RNA / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D011954:Receptors, Dopamine; D012313:RNA