Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined the effects on sleep and brain temperature of bilateral microinjections of adenosine and adenosine analogs to the preoptic area (PO) of rats. Administration of adenosine (12.5 nmoles), a nonselective adenosine A1/A2 receptor agonist NECA (N-ethyl-carboxamido-adenosine, 1.0 nmole), and the selective adenosine A1 receptor agonist CPA (cyclopentyladenosine, 0.25, 0.5 nmoles) increased total sleep primarily through an enhancement in deep slow-wave sleep (SWS2), while adenosine also increased REM sleep. Administration of 12.5 nmoles adenosine and 0.25 nmoles CPA did not affect brain temperature, while 1.0 nmole NECA and 0.5 nmoles CPA caused a transient and prolonged hypothermia, respectively. Administration of the selective adenosine A2 receptor agonist CV-1808 (2-phenylaminoadenosine, 5, 10 nmoles) had no effect on sleep or brain temperature. The present results demonstrate a site for the central hypnotic action of adenosine, and a functional role for adenosine A1 receptors in the hypothalamus.
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PMID:Role of adenosine in sleep and temperature regulation in the preoptic area of rats. 178 Mar 43

1. The effects of adenosine, the adenosine analogue, 2-chloroadenosine (2-CADO), the specific adenosine A1 receptor agonist, N6-cyclopentyladenosine (CPA) and A2 receptor agonist 5'-(N-cyclopropyl) carboxamidoadenosine (CPCA), were examined against seizures induced by acute administration of pentylenetetrazole (PTZ), 60 mg kg-1, and PTZ kindled seizures, in rats. 2. Adenosine 1000 mg kg-1, i.p., 5 min pretreatment and CPA 10 mg kg-1 i.p., 60 min pretreatment, showed significant protection against acute PTZ-induced seizures while, CPCA up to 10 mg kg-1 was ineffective. The adenosine analogue 2-CADO in a dose of 5 mg kg-1 was only partially protective and on increasing the dose to 10 mg kg-1, this protection was lost. 3. Theophylline, a non specific adenosine receptor antagonist at 50 mg kg-1 and the specific adenosine A1 receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), at 1 mg kg-1, if administered before the maximally protective doses of adenosine and CPA, completely reversed the protection afforded by them against PTZ seizures. While, pretreatment with the adenosine A2 receptor antagonist, 3,7-dimethyl-1-propargylxanthine (DMPX), failed to reverse the protection. 4. Adenosine and the adenosine A1 receptor agonist in doses that protected against seizures after acute PTZ administration, offered only incomplete protection when tested against PTZ kindled seizures. 5. The effects of adenosine and adenosine receptor agonists on mean arterial pressure, heart rate and rectal temperature were studied, to rule out the possibility of their systemic effects mediating the protection of PTZ seizures. All these agents produced a fall in mean arterial pressure, heart rate and hypothermia in the doses exhibiting an anticonvulsant response. While the effect on blood pressure and heart rate was immediate i.e. seen within 5 min and, maintained throughout the observation period, the development of hypothermia lagged behind the onset of hypotension and bradycardia. However, there was no correlation between haemodynamic and hypothermic response and the anticonvulsant effect. 6. The results indicate that the adenosine mediated anticonvulsant effect is via stimulation of A1 receptors. Hypotension and hypothermia do not appear to contribute to the protection observed with adenosine and the adenosine A1 receptor agonists.
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PMID:Effect of adenosine receptor modulation on pentylenetetrazole-induced seizures in rats. 911 21