An adenosine A(2A) antagonist injected in the NTS reverses thermal prolongation of the LCR in decerebrate piglets.
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.
Xia
Luxi
L
Department of Physiology, Dartmouth Medical School, Lebanon, NH 03756, United States.
Bartlett
Donald
D
Leiter
J C
JC
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*
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
J Appl Physiol (1985). 2008 Jan;104(1):269-74
17962578
J Appl Physiol (1985). 2007 Jan;102(1):54-62
16959905
N Engl J Med. 1970 Feb 26;282(9):461-6
5411868
Can J Physiol Pharmacol. 1983 Jun;61(6):599-607
6576843
J Appl Physiol Respir Environ Exerc Physiol. 1982 Aug;53(2):455-62
7118665
J Pediatr. 1978 Jan;92(1):91-5
22592
Respir Physiol Neurobiol. 2007 May 14;156(2):229-33
17137847
Am J Med. 2001 Dec 3;111 Suppl 8A:69S-77S
11749929
Clin Perinatol. 1992 Dec;19(4):757-71
1464189
Pflugers Arch. 1986 Aug;407(2):190-8
3748780
Semin Perinatol. 2004 Aug;28(4):273-8
15565787
Pediatrics. 1975 May;55(5):640-9
236536
J Physiol. 1991 May;436:131-47
2061828
Neurosci Res. 2001 Feb;39(2):221-32
11223468
Biol Neonate. 1994;65(3-4):194-7
8038282
Am J Physiol. 1977 Jul;233(1):R30-6
18025
Respir Physiol Neurobiol. 2004 Jul 20;141(2):201-11
15239970
J Neurochem. 2005 Mar;92(6):1542-9
15748171
Respir Physiol Neurobiol. 2007 Nov 15;159(2):127-38
17644048
Ann Otol Rhinol Laryngol. 1983 Jan-Feb;92(1 Pt 1):24-8
6824275
J Appl Physiol Respir Environ Exerc Physiol. 1982 Jul;53(1):105-9
6811520
Science. 1994 Feb 4;263(5147):689-92
8303279
J Appl Physiol (1985). 2001 Apr;90(4):1570-6
11247962
Pediatrics. 1969 Apr;43(4):510-8
5777065
Brain Res Brain Res Rev. 2005 Dec 1;50(1):169-83
16043226
Neuroscience. 2000;100(1):53-62
10996458
J Appl Physiol (1985). 2006 Jan;100(1):91-7
16141383
Respir Physiol Neurobiol. 2006 Jan 25;150(1):82-6
15993656
J Appl Physiol (1985). 2003 May;94(5):1883-95
12679348
J Physiol. 1976 Jul;259(2):339-56
957251
J Appl Physiol (1985). 1994 Jan;76(1):403-8
8175537
Brain Res. 1992 Jul 3;584(1-2):197-206
1515939
J Dev Physiol. 1982 Dec;4(6):353-70
7183712
Am J Physiol. 1986 May;250(5 Pt 2):R902-9
3706575
J Neurobiol. 1976 Nov;7(6):483-94
1003197
Pediatr Res. 1981 Nov;15(11):1462-4
7301467
Pediatr Res. 1999 Mar;45(3):370-6
10088657
Respir Physiol. 1985 Jun;60(3):377-85
3929349
J Appl Physiol (1985). 2005 Mar;98(3):780-6
15542573
J Appl Physiol (1985). 2007 Oct;103(4):1205-11
17656623
Brain Res. 1991 Jan 18;539(1):169-74
1707739
J Pediatr. 1983 Dec;103(6):969-74
6644438
Brain Res. 1998 Oct 5;807(1-2):193-8
9757034
J Appl Physiol (1985). 2007 Nov;103(5):1864-72
17823299
Brain Res. 2006 Feb 3;1071(1):42-53
16413509
N Engl J Med. 2006 May 18;354(20):2112-21
16707748
Otolaryngol Head Neck Surg. 1992 Dec;107(6 Pt 1):775-82
1470457