Role of calcium channels in effects of antidepressant drugs on responsiveness to pain.
The effect of acute and chronic treatment with three antidepressant drugs on the cortical L-type calcium channel (measured as [3H]nitrendipine binding sites) and on the responsiveness to pain (assessed in the hot-plate test) was tested on the Wistar rat. Acute administration of antidepressants did not affect the characteristics of calcium channels and did not significantly prolong the hot-plate latency. However, a combination of antidepressants with nifedipine brought about analgesia. Chronic administration of imipramine did not significantly affect the characteristics of calcium channels but produced a moderate analgesic effect. In contrast, chronic administration of citalopram and chlorprothixene increased the density of [3H]nitrendipine binding sites and induced hyperalgesia, which was nullified by acute administration of nifedipine. The results confirm that calcium channels may be involved in analgesia and hyperalgesia and indicate that chronic treatment with some antidepressant may induce an increase in the density of cortical calcium channels.
Antkiewicz-Michaluk
L
L
Department of Biochemistry, Polish Academy of Sciences, Kraków.
Romańska
I
I
Michaluk
J
J
Vetulani
J
J
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D002749:Chlorprothixene / Q000494:pharmacology; D015283:Citalopram / Q000494:pharmacology; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology; D009568:Nitrendipine / Q000378:metabolism; D010146:Pain / Q000523:psychology*; D010147:Pain Measurement; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D000928:Antidepressive Agents; D015220:Calcium Channels; D014665:Vasodilator Agents; D015283:Citalopram; D009568:Nitrendipine; D002749:Chlorprothixene; D009543:Nifedipine; D007099:Imipramine