This Article Full Text Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mizuki, T. Articles by Izumi, F. Search for Related Content PubMed PubMed Citation Articles by Mizuki, T. Articles by Izumi, F.

(Stroke. 1995;26:2333-2337.)
© 1995 American Heart Association, Inc.

Articles

Differential Changes in - and ß-Adrenoceptors in the Cerebral Cortex and Hippocampus of the Mongolian Gerbil After Unilateral Brain Ischemia

Tsunetaka Mizuki, MD, PhD; Hideyuki Kobayashi, PhD; Susumu Ueno, MD, PhD; Yasuhide Nakashima, MD, PhD; Akio Kuroiwa, MD, PhD Futoshi Izumi, MD, PhD

From the Department of Pharmacology (H.K., S.U., F.I.) and the Second Department of Medicine (T.M., Y.N., A.K.), University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.

Correspondence to Hideyuki Kobayashi, PhD, Department of Pharmacology, Miyazaki Medical College, 5200 Kiyotake, Miyazaki 889-16, Japan.

Background and Purpose Changes in adrenoceptors in the cerebral cortex and hippocampus of Mongolian gerbils after brain ischemia were investigated.

Methods Twenty-four hours after unilateral occlusion of the common carotid artery, ₁-, ₂-, and ß-receptors of the membrane fraction of the cerebral cortex or the hippocampus were analyzed by binding assay with the use of [³H]prazosin, [³H]p-aminoclonidine, and [¹²⁵I]cyanopindolol as radioligands, respectively.

Results In the cerebral cortex, the number of binding sites (B_max) and the dissociation constant (K_d) of [³H]prazosin were not altered, whereas the B_max value of [³H]p-aminoclonidine binding was decreased by 30% and that of [¹²⁵I]cyanopindolol binding by 16% without a change in K_d values for the ligands. In the hippocampus, the B_max values of [³H]prazosin, [³H]p-aminoclonidine, and [¹²⁵I]cyanopindolol bindings were decreased by 21%, 53%, and 19%, respectively, but there was no change in the K_d values for the ligands. The bindings of [³H]prazosin and [³H]p-aminoclonidine of the contralateral side of the cerebral cortex and the hippocampus were not altered by ischemia, but that of [¹²⁵I]cyanopindolol was decreased when compared with normal tissues.

Conclusions These results show that ischemia results in a decrease in brain ₁-, ₂-, and ß-adrenoceptors to various degrees, depending on the brain area and the types of receptors, and suggest that vulnerability of the brain to ischemia is different depending on brain areas and that the regulatory mechanisms of ₁-, ₂-, and ß-receptors are different.

Key Words: norepinephrine • cerebral ischemia • gerbils

This article has been cited by other articles:

				D. Ma, N. Rajakumaraswamy, and M. Maze {alpha}2-Adrenoceptor agonists: shedding light on neuroprotection? Br. Med. Bull., January 31, 2005; 71(1): 77 - 92. [Abstract] [Full Text] [PDF]

				Y. Miura, G. B. Mackensen, B. Nellgard, R. D. Pearlstein, R. D. Bart, F. Dexter, and D. S. Warner Effects of Isoflurane, Ketamine, and Fentanyl/N2O on Concentrations of Brain and Plasma Catecholamines During Near-Complete Cerebral Ischemia in the Rat Anesth. Analg., April 1, 1999; 88(4): 787 - 787. [Abstract] [Full Text] [PDF]