Central thermoregulatory effects of lactate in the toad Bufo paracnemis

Citation
Lgs. Branco et Aa. Steiner, Central thermoregulatory effects of lactate in the toad Bufo paracnemis, COMP BIOC A, 122(4), 1999, pp. 457-461
Citations number
20
Categorie Soggetti
Animal Sciences",Physiology
Journal title
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY
ISSN journal
10956433 → ACNP
Volume
122
Issue
4
Year of publication
1999
Pages
457 - 461
Database
ISI
SICI code
1095-6433(199904)122:4<457:CTEOLI>2.0.ZU;2-L
Abstract
Hypoxia induces a regulated decrease in body temperature (Tb; anapyrexia) i n organisms ranging from protozoans to mammals, but very little is known ab out the mechanisms involved. Several candidates have been suggested to medi ate hypoxia-induced anapyrexia, among them lactate, which is a classical co mpanion of hypoxic stress in vertebrates. The present study was designed to assess the central thermoregulatory effects of lactate in Bujo paracnemis. Toads equipped with a temperature probe were tested over a thermal gradien t (10-40 degrees C). Lactate injected systemically (4.0 mmol kg(-1)) caused a significant reduction of Tb from 24.6 +/- 2.1 to 17.4 +/- 3.9 degrees C. To assess the role of central thermoregulatory mechanisms, a lower dose (0 .4 mmol kg(-1)) of lactate was injected into the fourth cerebral ventricle or systemically. Intracerebroventricular injection of lactate caused a simi lar decrease in Tb, whereas systemic injection caused no change. The data i ndicate that lactate may play a role in hypoxia-induced anapyrexia in centr al rather than peripheral sites. (C) 1999 Elsevier Science Inc. All rights reserved.