Quantitative autoradiography of beta 1- and beta 2-adrenergic receptors in rat brain.

Abstract

We have used quantitative autoradiography to localize in rat brain /3i-and . and 832 receptors are distributed heterogeneously among afatomically discrete nuclei and subregions of rat brain. This new technology will enable investigators to examine -adrenergic receptor subtypes in the brain at a much higher anatomical resolution than was previously possible. METHODSMale Sprague-Dawley rats (200-250 g) were decapitated, the brains mounted on a cryostat chuck, and 32-gm sections were cut, thawed, and mounted onto microscope slides as described (10). The sections were stored overnight at -20'C and then stored at -70'C for up to a week before use. The slides were allowed to warm to room temperature 20 min before use. They were then immersed in a Coplin slide jar containing 35 ml of a Tris-saline buffer (20 mM Tris'HCl/135 mM NaCl, pH 7.4), 1251-labeled (1251I-pindolol) pindolol (prepared as described in ref. 12), and various competing drugs. After incubation for 70 min at 230C, the slides were washed (3 x 20 min) in 40C Tris-saline buffer, rinsed quickly in cold distilled water to remove buffer salts, and rapidly dried on a slide warmer at 60'C. We either removed labeled brain sections for scintillation counting or exposed them for either 4.5 or 24 hr against LKB Ultrofilm, as described (10) 1585The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Beta 1- and beta 2-adrenergic 125I-pindolol binding sites in the interpeduncular nucleus of the rat: normal distribution and the effects of deafferentation

“…The use of the selective antagonists ICI 89,406 and ICI 118,551 permitted the determination of the relative proportions of the p,-and &subtypes; using appropriate conditions, there is 97% occupancy of one subtype by one of these ICI drugs with less than 3% occupancy of the other (Rainbow et al, 1984). We could therefore correlate the subnuclear distribution and density of these 2 subtypes with the specific distribution of both noradrenergic and non-noradrenergic afferents in the IPN.…”

“…The slides were allowed to come to room temperature for 20 min. The radioautography procedure described by Rainbow et al (1984) was used to determine the distribution of total /3-adrenergic receptor sites and of the p,-and &subtypes.…”

“…The FRs contain cholinergic afferents that project to the same targets as the noradrenergic afferents and tachykinin-containing afferents that project to different subnuclei (Hemmendinger and Moore, 1984;Artymyshyn and Murray, 1985;Groenewegen et al, 1986;Battisti et al, 1987;Contestabile et al, 1987;Eckenrode et al, 1987;Murray et al, 1988). The IPN is also known to contain a substantial number of @-adrenergic receptors (Palacios and Kuhar, 1982;Rainbow et al, 1984) but the subnuclear distribution of the receptor subtypes and their relation to the noradrenergic afferents have not been described.…”

“…The normal distribution and density of the P-adrenergic receptors in the IPN can be labeled with the antagonist lZ51-pindolol (1251-PIN) (Rainbow et al, 1984). The use of the selective antagonists ICI 89,406 and ICI 118,551 permitted the determination of the relative proportions of the p,-and &subtypes; using appropriate conditions, there is 97% occupancy of one subtype by one of these ICI drugs with less than 3% occupancy of the other (Rainbow et al, 1984).…”

“…Recent studies suggest that there may also be a differential anatomical localization of these subtypes in the CNS. The fi,-receptor subtype accounts for the majority of /3-adrenergic receptors in most areas of the rat brain, but the &-receptor subtype predominates in the cerebellum (Minnemann et al, 1979b;Palacios and Kuhar, 1982;Rainbow et al, 1984). Most of the adaptive changes that have been recorded for the fl-adrenergic receptors, following perturbations of the CNS, can be attributed to changes in the &-receptor subtype (Minnemann et al, 1979a;UPrichard et al, 1979;Dooley and Bittiger, 1987).…”