Distribution and subtype determination of beta-receptors in the spinal cord of the adult rat.
1. We determined the number of beta-receptors in the whole spinal cord of the adult rat and in the cervical, thoracal, and lumbal/sacral parts. 2. The undivided spinal cord contains 47 +/- 10 fmol/mg beta-receptors (KD = 2066 +/- 982 pmol/liter), and the cervical part of the spinal cord contains 53 +/- 8 fmol/mg protein (KD = 3224 +/- 1775 pmol/liter). The thoracal part shows 40 +/- 1 fmol/mg protein (KD = 3229 +/- 104 pmol/liter), and the lumbal/sacral spinal cord contains 48 +/- 8 fmol/mg protein (KD = 3610 +/- 1610 pmol/liter). 3. Competitive inhibition studies with l-practolol, dl-atenolol, and ICI 118,551 were performed and we calculated by a computer program in the whole spinal cord the following ratio of beta-receptor subtypes: 80 +/- 5% Beta 1-receptors and 20 +/- 5% beta 2-receptors. 4. The basal and (-)-isoproterenol- and NaF-stimulated activity of adenylate cyclase was highest in the cervical part of the spinal cord and equally distributed between the thoracal and the lumbal/sacral parts. 5. The whole synaptosomal protein of the cervical part of the spinal cord contained 132 +/- 20 fmol, the thoracal part 117 +/- 3 fmol, and the lumbal/sacral part 133 +/- 22 fmol.
Schrader
E
E
Department of Pharmacology, University of Regensburg, West Germany.
Grobecker
H
H
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001262:Atenolol / Q000378:metabolism; D001667:Binding, Competitive; D004082:Dihydroalprenolol / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D011217:Practolol / Q000378:metabolism; D011433:Propranolol / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000032:analysis* / Q000378:metabolism; D013116:Spinal Cord / Q000032:analysis* / Q000378:metabolism
D011943:Receptors, Adrenergic, beta; D001262:Atenolol; D004082:Dihydroalprenolol; D011433:Propranolol; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D011217:Practolol