title: An adenosine A(2A) antagonist injected in the NTS reverses thermal prolongation of the LCR in decerebrate piglets.
abstract: Hyperthermia prolongs the laryngeal chemoreflex (LCR). Under normothermic conditions, adenosine antagonists shorten and adenosine A(2A) (Ad-A(2A)) agonists prolong the LCR. Therefore, we tested the hypothesis that SCH-58261, an Ad-A(2A) receptor antagonist, would prevent thermal prolongation of the LCR when injected unilaterally within the nucleus of the solitary tract (NTS). We studied decerebrate piglets aged 4-13 days. We elicited the LCR by injecting 0.1ml of water into the larynx and recorded integrated phrenic nerve activity. The laryngeal chemoreflex was prolonged when the body temperature of each piglet was raised approximately 2.5 degrees C, and SCH-58261 reversed the thermal prolongation of the LCR when injected into the NTS (n=13), but not when injected in the nucleus ambiguus (n=9). Injections of vehicle alone into the NTS did not alter the thermal prolongation of the LCR (n=9). We conclude that activation of adenosine receptors, perhaps located on GABAergic neurons in the NTS, contributes to thermal prolongation of the LCR.
authors.affiliation: Department of Physiology, Dartmouth Medical School, Lebanon, NH 03756, United States.
authors.forename: Luxi
authors.initials: L
authors.lastname: Xia
authors.forename: Donald
authors.initials: D
authors.lastname: Bartlett
authors.forename: J C
authors.initials: JC
authors.lastname: Leiter
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001831:Body Temperature / Q000187:drug effects / Q000502:physiology; D003655:Decerebrate State / Q000503:physiopathology*; D005260:Female; D005334:Fever; D007830:Larynx / Q000187:drug effects* / Q000502:physiology; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D012018:Reflex / Q000187:drug effects / Q000502:physiology; D017552:Solitary Nucleus / Q000187:drug effects*; D013552:Swine; D013696:Temperature; D014230:Triazoles / Q000494:pharmacology*
chemical_list: C098657:5-amino-7-(2-phenylethyl)-2-(2-furyl)pyrazolo(4,3-e)-1,2,4-triazolo(1,5-c)pyrimidine; D018696:Neuroprotective Agents; D011743:Pyrimidines; D014230:Triazoles
references.citation: J Appl Physiol (1985). 2008 Jan;104(1):269-74
references.pmid: 17962578
references.citation: J Appl Physiol (1985). 2007 Jan;102(1):54-62
references.pmid: 16959905
references.citation: N Engl J Med. 1970 Feb 26;282(9):461-6
references.pmid: 5411868
references.citation: Can J Physiol Pharmacol. 1983 Jun;61(6):599-607
references.pmid: 6576843
references.citation: J Appl Physiol Respir Environ Exerc Physiol. 1982 Aug;53(2):455-62
references.pmid: 7118665
references.citation: J Pediatr. 1978 Jan;92(1):91-5
references.pmid: 22592
references.citation: Respir Physiol Neurobiol. 2007 May 14;156(2):229-33
references.pmid: 17137847
references.citation: Am J Med. 2001 Dec 3;111 Suppl 8A:69S-77S
references.pmid: 11749929
references.citation: Clin Perinatol. 1992 Dec;19(4):757-71
references.pmid: 1464189
references.citation: Pflugers Arch. 1986 Aug;407(2):190-8
references.pmid: 3748780
references.citation: Semin Perinatol. 2004 Aug;28(4):273-8
references.pmid: 15565787
references.citation: Pediatrics. 1975 May;55(5):640-9
references.pmid: 236536
references.citation: J Physiol. 1991 May;436:131-47
references.pmid: 2061828
references.citation: Neurosci Res. 2001 Feb;39(2):221-32
references.pmid: 11223468
references.citation: Biol Neonate. 1994;65(3-4):194-7
references.pmid: 8038282
references.citation: Am J Physiol. 1977 Jul;233(1):R30-6
references.pmid: 18025
references.citation: Respir Physiol Neurobiol. 2004 Jul 20;141(2):201-11
references.pmid: 15239970
references.citation: J Neurochem. 2005 Mar;92(6):1542-9
references.pmid: 15748171
references.citation: Respir Physiol Neurobiol. 2007 Nov 15;159(2):127-38
references.pmid: 17644048
references.citation: Ann Otol Rhinol Laryngol. 1983 Jan-Feb;92(1 Pt 1):24-8
references.pmid: 6824275
references.citation: J Appl Physiol Respir Environ Exerc Physiol. 1982 Jul;53(1):105-9
references.pmid: 6811520
references.citation: Science. 1994 Feb 4;263(5147):689-92
references.pmid: 8303279
references.citation: J Appl Physiol (1985). 2001 Apr;90(4):1570-6
references.pmid: 11247962
references.citation: Pediatrics. 1969 Apr;43(4):510-8
references.pmid: 5777065
references.citation: Brain Res Brain Res Rev. 2005 Dec 1;50(1):169-83
references.pmid: 16043226
references.citation: Neuroscience. 2000;100(1):53-62
references.pmid: 10996458
references.citation: J Appl Physiol (1985). 2006 Jan;100(1):91-7
references.pmid: 16141383
references.citation: Respir Physiol Neurobiol. 2006 Jan 25;150(1):82-6
references.pmid: 15993656
references.citation: J Appl Physiol (1985). 2003 May;94(5):1883-95
references.pmid: 12679348
references.citation: J Physiol. 1976 Jul;259(2):339-56
references.pmid: 957251
references.citation: J Appl Physiol (1985). 1994 Jan;76(1):403-8
references.pmid: 8175537
references.citation: Brain Res. 1992 Jul 3;584(1-2):197-206
references.pmid: 1515939
references.citation: J Dev Physiol. 1982 Dec;4(6):353-70
references.pmid: 7183712
references.citation: Am J Physiol. 1986 May;250(5 Pt 2):R902-9
references.pmid: 3706575
references.citation: J Neurobiol. 1976 Nov;7(6):483-94
references.pmid: 1003197
references.citation: Pediatr Res. 1981 Nov;15(11):1462-4
references.pmid: 7301467
references.citation: Pediatr Res. 1999 Mar;45(3):370-6
references.pmid: 10088657
references.citation: Respir Physiol. 1985 Jun;60(3):377-85
references.pmid: 3929349
references.citation: J Appl Physiol (1985). 2005 Mar;98(3):780-6
references.pmid: 15542573
references.citation: J Appl Physiol (1985). 2007 Oct;103(4):1205-11
references.pmid: 17656623
references.citation: Brain Res. 1991 Jan 18;539(1):169-74
references.pmid: 1707739
references.citation: J Pediatr. 1983 Dec;103(6):969-74
references.pmid: 6644438
references.citation: Brain Res. 1998 Oct 5;807(1-2):193-8
references.pmid: 9757034
references.citation: J Appl Physiol (1985). 2007 Nov;103(5):1864-72
references.pmid: 17823299
references.citation: Brain Res. 2006 Feb 3;1071(1):42-53
references.pmid: 16413509
references.citation: N Engl J Med. 2006 May 18;354(20):2112-21
references.pmid: 16707748
references.citation: Otolaryngol Head Neck Surg. 1992 Dec;107(6 Pt 1):775-82
references.pmid: 1470457