The effect of melanotropic peptides on binding of [(3)H]dihydroalprenolol-hydrochloride to hypothalamic membranes.
In the present work we studied the interaction of alpha-melanocyte-stimulating hormone (alpha-MSH) and ACTH-(1-24) with beta-adrenergic receptors in hypothalamic membranes from rat brain. Saturation curves for [(3)H]dihydroalprenolol-hydrochloride ([(3)H]DHA) binding in the presence of the peptides revealed a decreased binding capacity (Bmax). The dissociation constant (Kd) was, however, not affected by alpha-MSH or ACTH-(1-24). These data indicate a non competitive interaction between these melanocortin peptides and [(3)H]DHA on beta-adrenergic receptors in hypothalamic membranes.
Stutz
R
R
Laboratorio de Fisiología, Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000, Córdoba, Argentina.
Sanchez
M
M
Salvatierra
N A
NA
Scimonelli
T
T
D000319:Adrenergic beta-Antagonists / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D003366:Cosyntropin / Q000378:metabolism*; D004082:Dihydroalprenolol / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D011485:Protein Binding; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D000521:alpha-MSH / Q000378:metabolism*
D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; D003366:Cosyntropin; D000521:alpha-MSH; D004082:Dihydroalprenolol