TY - JOUR

T1 - Alpha-adrenergic receptors in rat skeletal muscle

AU - Rattigan, S

AU - Appleby, G J

AU - Edwards, S J

AU - McKinstry, W J

AU - Colquhoun, E Q

AU - Clark, M G

AU - Richter, Erik A.

PY - 1986

Y1 - 1986

N2 - Sarcolemma-enriched preparations from muscles rich in slow oxidative red fibres contained specific binding sites for the alpha 1 antagonist, prazosin (e.g. soleus Kd 0.13 nM, Bmax 29 fmol/mg protein). Binding sites for prazosin were almost absent from white muscle. Displacement of prazosin binding from sarcolemma of soleus muscle (phentolamine greater than phenylephrine greater than idazoxan greater than yohimbine) suggested that the receptors were alpha 1. Binding sites for dihydroalprenolol (beta antagonist) were also more concentrated on red than white muscle and outnumbered prazosin sites by approx. 10:1. Binding sites for idazoxan (alpha 2 antagonist) were undetectable. Contamination of sarcolemma-enriched preparations by endothelial tissue indicated by the activity of angiotensin converting enzyme did not correlate with prazosin binding. It is concluded that post-synaptic alpha 1 adrenergic receptors are present on the sarcolemma of slow oxidative red fibres of rat skeletal muscle. The presence provides the mechanistic basis for apparent alpha-adrenergic effects to increase glucose and oxygen uptake in perfused rat hindquarter.

AB - Sarcolemma-enriched preparations from muscles rich in slow oxidative red fibres contained specific binding sites for the alpha 1 antagonist, prazosin (e.g. soleus Kd 0.13 nM, Bmax 29 fmol/mg protein). Binding sites for prazosin were almost absent from white muscle. Displacement of prazosin binding from sarcolemma of soleus muscle (phentolamine greater than phenylephrine greater than idazoxan greater than yohimbine) suggested that the receptors were alpha 1. Binding sites for dihydroalprenolol (beta antagonist) were also more concentrated on red than white muscle and outnumbered prazosin sites by approx. 10:1. Binding sites for idazoxan (alpha 2 antagonist) were undetectable. Contamination of sarcolemma-enriched preparations by endothelial tissue indicated by the activity of angiotensin converting enzyme did not correlate with prazosin binding. It is concluded that post-synaptic alpha 1 adrenergic receptors are present on the sarcolemma of slow oxidative red fibres of rat skeletal muscle. The presence provides the mechanistic basis for apparent alpha-adrenergic effects to increase glucose and oxygen uptake in perfused rat hindquarter.

KW - Animals

KW - Binding Sites

KW - Dihydroalprenolol

KW - Dioxanes

KW - Female

KW - Idazoxan

KW - Kinetics

KW - Male

KW - Muscles

KW - Peptidyl-Dipeptidase A

KW - Phentolamine

KW - Phenylephrine

KW - Prazosin

KW - Rats

KW - Receptors, Adrenergic, alpha

KW - Sarcolemma

KW - Yohimbine

M3 - Journal article

C2 - 3013164

VL - 136

SP - 1071

EP - 1077

JO - Biochemical and Biophysical Research Communications

JF - Biochemical and Biophysical Research Communications

SN - 0006-291X

IS - 3

ER -