title: Involvement of purinergic signalling in central mechanisms of body temperature regulation in rats.
abstract: 1. P2 purinoreceptors are present in hypothalamic and brainstem nuclei that are involved in the regulation of body temperature (T(b)). The role of ATP acting on these P2 receptors in thermoregulation was investigated by studying the effects of the stable ATP analogue alpha,beta-methyleneATP (alpha,beta-meATP) and P2 receptor antagonists suramin and pyridoxal-5'-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on T(b) when injected intracerebroventricularly (i.c.v.) via a pre-implanted cannula in conscious rats at various ambient temperatures and during lipopolysaccharide (LPS)-induced fever. 2. Depending on ambient temperature, alpha,beta-meATP (0.2 micromol, i.c.v.) induced a fall in T(b) (-3.3 degrees C, P<0.05), no changes in T(b) when compared to pre-injection levels, or an increase in T(b) ( approximately 1.0 degrees C, P<0.05) in rats maintained at 10 degrees C, 25 degrees C and 30 degrees C ambient temperature, respectively. 3. Suramin (7 nmol, i.c.v.) induced a lasting (up to 6 h) increase in T(b) (on average 1.2 degrees C, P<0.05) in rats kept at 25 degrees C or 30 degrees C, but failed to induce any rise in T(b) in rats at 10 degrees C ambient temperature. An increase in T(b) was also observed in rats (25 degrees C ambient temperature) treated with PPADS (0.2 micromol, i.c.v.). 4. alpha,beta-meATP (0.2 micromol) injected i.c.v. or directly into the anterior hypothalamus caused a profound fall in T(b) (by 0.9 degrees C and 1.0 degrees C, respectively; P<0.05) during LPS (E.coli; 50 microg kg(-1))-induced fever in rats at 25 degrees C ambient temperature. Fever was initiated more rapidly in rats treated with suramin (7 nmol) or PPADS (70 nmol), however its late phase was unaffected. Suramin (7 nmol) and PPADS (70 nmol) injected at the time when fever was already developed (2.5 h after LPS injections) did not alter febrile T(b). 5. These data indicate that purinergic signalling may play a significant role in central mechanisms of T(b) regulation at various ambient temperatures and during fever.
authors.affiliation: Department of Physiology, Royal Free and University College London Medical School, Rowland Hill Street, London NW3 2PF, UK. a.gourine@rfc.ucl.ac.uk
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Gourine
authors.forename: Ekaterina V
authors.initials: EV
authors.lastname: Melenchuk
authors.forename: Dmitry M
authors.initials: DM
authors.lastname: Poputnikov
authors.forename: Valery N
authors.initials: VN
authors.lastname: Gourine
authors.forename: K Michael
authors.initials: KM
authors.lastname: Spyer
mesh_terms: D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000031:analogs & derivatives; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects / Q000502:physiology*; D001921:Brain / Q000187:drug effects / Q000502:physiology; D005334:Fever / Q000139:chemically induced / Q000503:physiopathology; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology; D007276:Injections, Intraventricular; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D058919:Purinergic P2 Receptor Antagonists; D011732:Pyridoxal Phosphate / Q000008:administration & dosage / Q000031:analogs & derivatives*; D051381:Rats; D017208:Rats, Wistar; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013498:Suramin / Q000008:administration & dosage
chemical_list: D008070:Lipopolysaccharides; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D011732:Pyridoxal Phosphate; D013498:Suramin; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate