α2-agonist binding sites in brain: [125I]Para-iodoclonidine versus [3H]para-aminoclonidine

Autoradiographic Comparison of [3H]-Clonidine Binding to Non-Adrenergic Sites and α2-Adrenergic Receptors in Human Brain

“…This is a surprising difference from the positive correlation we observed (p ϭ .0003, r 2 ϭ 0.385) across 27 brain regions between these sites (Figure 2). However, of the eight brain regions in common between our two studies (cortical layers 1, 2-4, 5-6, hippocampal layer CA1, dentate gyrus, caudate putamen, raphe nuclei, (Alburges et al 1993), whereas antagonists bind equally to low and high affinity states of ␣ 2 AR. This difference in the states of ␣ 2 AR labeled by [ 3 H]-clonidine (high affinity states), versus both low and high affinity states in their study (De Vos et al 1994) might underlie the different correlations between our studies.…”

Beta 2-adrenergic receptors are expressed by glia in vivo in the normal and injured central nervous system in the rat, rabbit, and human

“…i2-'I-PIC autoradiographic binding protocol (a,-ARs). After being brought to room temperature, the slides were immersed for 20 min at 22°C in a preincubation solution containing 170 mM Tris-HCI and 10 mM MgCI, (pH 7.4) (Alburges et al, 1993). This was followed by a 2 hr incubation at 22°C in which the slides were laid flat and the tissue was covered with 1 ml of preincubation solution plus 100 PM of the 01~adrenergic-specific radioligand 2- [(2,6-dichloro-4-[1251]iodophenyl)iminolimidazolidine (12V-PIC, DuPont-New England Nuclear, Boston, MA).…”

Expression of ?2A adrenoceptors during rat neocortical development

“…[ 125 I]Paraclonidine, which has high affinity for all ␣ 2 adrenoceptor subtypes, was used for autoradiographic localization of ␣ 2 adrenoceptors as described previously (Alburges et al, 1993). This ligand was chosen in preference to others because of the high sensitivity, short exposure times, and low tissue quench inherent to the use of iodinated radioligands (Kuhar et al, 1985).…”