Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The behavioral and physiological effects of L-phenylisopropyladenosine, cyclohexyladenosine and 2-chloroadenosine were examined in mice and rats. These analogs of adenosine are agonists which bind with high affinity to putative central A1 receptors in vitro. Relatively low doses of these drugs administered i.p. produced marked sedation and hypothermia; higher doses resulted in an almost complete cessation of spontaneous motor activity as well as some ataxia. These analogs also antagonized seizures elicited by a variety of convulsants with different mechanisms of action. The differences observed in the anticonvulsant potencies of the analogs suggest that these effects are not produced by the interaction of these drugs with a single class of adenosine receptor. In particular, 2-chloroadenosine and cyclohexyladenosine appear to be more related to each other pharmacologically than to L-phenylisopropyladenosine. Because some of the anticonvulsant actions of L-phenylisopropyladenosine are not reversed by the adenosine antagonist theophylline, and are not shared by the other analogs, these may reflect actions mediated by other, perhaps nonpurinergic receptors. Although benzodiazepines also have sedative, hypothermic and anticonvulsant properties, responses to benzodiazepines can be clearly dissociated from responses to the adenosine agonists.
 ...
PMID:Sedative and anticonvulsant effects of adenosine analogs in mouse and rat. 705 24

In the apomorphine-induced climbing mouse assay, the potencies of the selective adenosine A1 receptor agonist, N6-cyclohexyladenosine (CHA), and the selective A2A adenosine receptor agonist, 2-p-(2-carboxyethyl) phenethylamino 5'-N-ethyl-carboxamidoadenosine (CGS 21680), and various dopamine receptor antagonists were as follows: SCH 23390 = haloperidol > raclopride > CHA = CGS 21680. While in catalepsy, their potencies were SCH 23390 > haloperidol > raclopride > CGS 21680. CHA failed to induce catalepsy due to significant sedation/ataxia. The combined administration of the ED15 dose of CHA failed to potentiate the ED50 value of SCH 23390, raclopride, or haloperidol in the apomorphine-induced climbing mouse assay. However, the combined administration of the ED15 dose of CGS 21680 significantly decreased the ED50 of raclopride by 8.0-fold and haloperidol by 35-fold. The adenosine A2A receptor antagonist, 1,3,7-trimethyl-8-(3-chlorostyryl)xanthine (CSC), significantly decreased catalepsy induced by raclopride and haloperidol, while the adenosine A1 receptor antagonist, 1,3-dimethyl-8-phenylxanthine (8-PT), was ineffective. The present results show that in behavioral assays predictive for antipsychotic activity, adenosine receptor agonists block behaviors in a similar manner to dopamine receptor antagonists.
 ...
PMID:Selective adenosine A2A receptor/dopamine D2 receptor interactions in animal models of schizophrenia. 872 May 78

Previous reports from our laboratory have demonstrated that ethanol- and cannabinoid-induced ataxia is modulated by cerebellar adenosine A(1) receptor because intracerebellar (i.c.b.) adenosine A(1) agonists potentiated and A(1) antagonist attenuated ataxia by these psychoactive drugs. In this study, the novel approach involving pretreatment with adenosine A(1) antisense oligodeoxynucleotide via multiple routes provided further direct evidence of mouse cerebellar A(1) modulation of ethanol- and cannabinoid-induced ataxia. Animal groups were pretreated with A(1) antisense and its mismatch by oral (p.o.) (3.12, 6.25, 12.5, 50 microg/12 h; total three treatments/each dose), intraperitoneal (i.p.) (3.12, 5, 10, 50 microg/12 h; total three treatments/each dose), and i.c.b. (2 microg/12 h; total three treatments) routes. Based on our standard rotorod test, marked antagonism to ethanol (2 g/kg; i.p.) and delta(9)-THC (15 microg; i.c.b)-induced ataxia was observed 12 h after the last antisense treatment. Pretreatment with A(1) receptor mismatch was without an effect. The antagonism following systemic (p.o.; i.p.) antisense pretreatment was dose-dependent. No change in the normal motor coordination was observed when the animals were pretreated with antisense or its mismatch followed by vehicle. Results of Western blotting using commercially available antibodies and cerebellar membranes from various animal groups which received antisense and its mismatch via three routes confirmed a significant decrease in the A(1) adenosine receptor protein. These results, for the first time, demonstrated an oral and systemic effectiveness of A(1) antisense towards adenosine receptors in the central nervous system.
 ...
PMID:Acute ethanol/cannabinoid-induced ataxia and its antagonism by oral/systemic/intracerebellar A1 adenosine receptor antisense in mice. 1244 80