Characterization of Norepinephrine Release in Rat Posterior Hypothalamus Using in vivo Brain Microdialysis

  • Sung, Ki-Wug (Department of Pharmacology, College of Medicine, The Catholic University of Korea) ;
  • Kim, Seong-Yun (Department of Pharmacology, College of Medicine, The Catholic University of Korea) ;
  • Kim, Ok-Nyu (Department of Pharmacology, College of Medicine, The Catholic University of Korea) ;
  • Lee, Sang-Bok (Department of Pharmacology, College of Medicine, The Catholic University of Korea)
  • Published : 2002.02.21

Abstract

In the present study, we used the microdialysis technique combined with high performance liquid chromatography (HPLC) and electrochemical detection to measure the extracellular levels of norepinephrine (NE) in the posterior hypothalamus in vivo, and to examine the effects of various drugs, affecting central noradrenergic transmission, on the extracellular concentration of NE in the posterior hypothalamus. Microdialysis probes were implanted stereotaxically into the posterior hypothalamus (coordinates: posterior 4.3 mm, lateral 0.5 mm, ventral 8 mm, relative to bregma and the brain surface, respectively) of rats, and dialysate collection began 2 hr after the implantation. The baseline level of monoamines in the dialysates were determined to be: NE $0.17{\pm}0.01,$ 3,4-dihydroxyphenylacetic acid (DOPAC) $0.94{\pm}0.07,$ homovanillic acid (HVA) $0.57{\pm}0.05$ pmol/sample (n=8). When the posterior hypothalamus was perfused with 90 mM potassium, maximum 555% increase of NE output was observed. Concomitantly, this treatment significantly decreased the output of DOPAC and HVA by 35% and 28%, respectively. Local application of imipramine $(50\;{\mu}M)$ enhanced the level of NE in the posterior hypothalamus (maximum 200%) compared to preperfusion control values. But, DOPAC and HVA outputs remained unchanged. Pargyline, an irreversible monoamine oxidase inhibitor, i.p. administered at a dose of 75 mg/kg, increased NE output (maximum 165%), while decreased DOPAC and HVA outputs (maximum 13 and 12%, respectively). These results indicate that NE in dialysate from the rat posterior hypothalamus were neuronal origin, and that manipulations which profoundly affected the levels of extracellular neurotransmitter had also effects on metabolite levels.

References

  1. Dahlstrom A, Fuxe K. Evidence for the existence of monoaminescontaining neurons in the central nervous system. 1. Demonstration of monoamines in the cell bodies of brain stem neurons. Acta Physiol Scand 62, Suppl 232: 1-80, 1964
  2. Florin-Lechner SM, Druhan JP, Aston-Jones G, Valentino RJ. Enhanced norepinephrine release in prefrontal cortex with burst stimulation of the locus coeruleus. Brain Res 742: 89-97, 1996
  3. McMillen BA, German DC, Shore PA. Function and pharmacological significance of brain dopamine and norepinephrine storage pools. Biochem Pharmacol 29: 3045-3050, 1980
  4. Nakata T, Berard W, Kogosov E, Alexander N. Microdialysis in the posterior hypothalamus: sodium chloride affects norepinephrine release, mean arterial pressure, heart rate and behavior in awake rats. Brain Res Bull 25: 593-598, 1990
  5. Sawchenko PE, Swanson LW. The organization of noradrenergic pathways from the brainstem to the paraventricular and supraoptic nuclei in the rat. Brain Res 257: 275-325, 1982
  6. Sun MK. Central neural organization and control of sympathetic nervous system in mammals. Prog Neurobiol 47: 157-233, 1995
  7. Sung K-W, Kim SY, Cho YJ, Lee KH, Lee SE. In vivo measurement of extracellular monoamines and their metabolites in the rat posterior hypothalamus using microdialysis technique. Kor J Physiol Pharmacal 28: 1-9, 1992
  8. Westerink BH, Damsma G, Rollema H, De Vries JB, Horn AS. Scope and limitations of in vivo brain dialysis: comparison of its application to various neurotransmitter systems. Life Sci 41:1763-1776, 1987
  9. Zettenstrom T, Sharp T, Collin AK, Ungerstedt U. In vivo measurement of extracellular dopamine and DOPAC in rat striatum after various dopamine-releasing drugs; implications for the origin of extracellular DOPAC. Eur J Phannacol148: 327-334, 1988
  10. Kim SY, Sung KW, Koh HC, Lee SB. Primary role of posterior hypothalamic cholinergic receptors in central regulation of blood pressure and heart rate in rats. Kor J Physiol Pharmacol 1:639-645, 1997
  11. Manning KA, Uhlrich DJ. The distribution of histaminergic axons in the superior colliculus of the cat. Neuroscience 55: 1075-1084, 1993
  12. Carter AJ. Hippocampal noradrenaline release in awake, freely moving rats is regulated by alpha-2 adrenoceptors but not by adenosine receptors. J Pharmacol Exp Ther 281: 648-654, 1997
  13. Paxinos G, Watson C. The Rat Brain in Stereotaxic Coordinates, 4th ed., Academic Press, New York, 1998
  14. Ungerstedt U. Microdialysis-principles and applications for studies in animals and man. J Intern Med 230: 365-373, 1991
  15. Colburn RW, Goodwin FK, Murphy DL, Bunney WE Jr, Davis JM. Quantitative studies of norepinephrine uptake by synaptosomes. Biochem Pharmacol 17: 957-964, 1968
  16. Blaustein M, Johnson EM Jr, Needleman P. Calcium-dependent norepinephrine release from presynaptic nerve ending in vitro. Proc Nat Acad Sci USA 69: 2237-2240, 1972
  17. Chave S, Kushikata T, Ohkawa H, Ishiara H, Grimaud D, Matsuki A. Effects oftwo volatile anesthetics (sevoflurane and halothane) on the hypothalamic noradrenaline release in rat brain. Brain Res 706: 293-296, 1996
  18. Singewald N, Guo L, Philippu A. Release of endogenous GABA in the posterior hypothalamus of the conscious rat: effects of drugs and experimentally induced blood pressure changes. Naunyn Schmiedebergs Arch Phamacal 347: 402-406, 1993
  19. Itoh Y, Oishi R, Nishibori M, Saeki K. In vivo measurement of noradrenaline and 3,4-dihydroxyphenylethyleneglycol in the rat hypothalamus by microdialysis: effects of various drugs affecting noradrenaline metabolism. J Pharmacol Exp Ther 255: 1090-1097, 1990
  20. Buccafusco J J. The role of central cholinergic neurons in the regulation of blood pressure and in experimental hypertension. Pharmacol Rev 48: 179-211, 1996
  21. Paton DM. Release induced by alternations in extracellular potassium and sodium and by veratridine and scorpion venom. In: Paton DM ed, Release of Catecholamines from Adrenergic Neurons. Pergamon, Oxford, p323-332, 1979
  22. Hashiguchi H, Ye SH, Ross-Cisneros F, Alexander N. Central nitric oxide donors attenuate cardiovascular and central norepinephrine responses to stress. Am J Physiol 272: R1447-1453, 1997
  23. Routledge C, Masden CA. Comparison of the effects of selected drugs on the release of hypothalamic adrenaline and noradrenaline measured in vivo. Brain Res 426: 103-111, 1987
  24. Benveniste H. Brain microdialysis. J Neurochem 52: 1667-1679, 1989
  25. Matsumoto M, Zornow MH, Rabin BC, Maze M. The alpha 2 adrenergic agonist, dexmedetomidine, selectively attenuates ischemia-induced increases in striatal norepinephrine concentrations. Brain Res 627: 325-329, 1993
  26. Schwartz D, Hernandez L, Hoebel BG. Fenfluramine administered systemically or locally increases extracellular serotonin in the lateral hypothalamus as measured by microdialysis. Brain Res 482: 261-270, 1989
  27. Lisa M, Filippelli A, Marmo E, Wible JH Jr, DiMicco JA. Microinjection of muscimol into posterior hypothalamus blocks cardiovascular response to experimental stress in rats. Pharmacol Res 21, Suppl 1: 9-10, 1989
  28. Thomas DN, Post RM, Pert A. Focal and systemic cocaine differentially affect extracellular norepinephrine in the locus coeruleus, frontal cortex and hippocampus of the anesthetized rat. Brain Res 645: 135-142, 1994
  29. Kiss JP, Vizi ES, Westerink BH. Effect of neostigmine on the hippocampal noradrenaline release: role of cholinergic receptors. Neuroreport 18: 81-86, 1999
  30. Hokfelt T, Fuxe K, Goldstein M. Immunohistochemical studies on monoamine-containing cell systems. Brain Res 62: 461-469, 1973
  31. Horn AS, Coyle JT, Snyder SH. Catecholamine uptake by synaptosomes from rat brain. Structure-activity relationships of drugs with differential effects on dopamine and norepinephrine neurons. Mol Pharmacol 7: 66-80, 1971
  32. Dampney RA. Functional organization of central pathways regulating the cardiovascular system. Physiol Rev 74: 323-364, 1994 https://doi.org/10.1152/physrev.1994.74.2.323
  33. Glowinski J. Properties and functions of intraneuronal monoamine compartments in central aminergic neurons. In: Iversen LL, Iversen SD, Snyder SH ed, Handbook of Psychopharmacology, Vol. 3. Plenum Press, New York, pI39-167, 1975