Antinociceptive effect of nifedipine and verapamil tested on rats chronically exposed to nicotine and after its withdrawal.

Abstract

Antinociceptive effect of nifedipine (15 mg/kg i.p.) and verapamil (10 mg/kg s.c.) was examined in rats chronically exposed to nicotine (6 mg/kg/day via Alzet osmotic pump for 28 days) and after nicotine withdrawal. Sham operated rats served as control for testing DMSO (dimethylsulfoxide, a solvent for nifedipine), nifedipine and verapamil alone. Nociception was measured by the tail-flick technique. Nifedipine, but not verapamil, injected to control rats produced a ceiling tail-flick latency (20 sec) 30 min after the injection, lasting for 10 min. In rats exposed to chronic nicotine for 3 days, nifedipine treatment exhibited ceiling tail-flick latency within 10 min lasting for 80 min. Tested in rats exposed to nicotine for 3 weeks, nifedipine treatment produced this effect 25 min after the injection lasting for 60 min. Nicotine withdrawal abolished this effect. Verapamil did not exhibit any significant changes in tail-flick latencies. These data support our hypothesis that smoking patients treated with nifedipine could be at a potential risk in developing a high pain threshold and missing the first sign of heart attack--a chest pain.

• Authors: V K Zbuzek, B Cohen, W Wu
• Journal: Life sciences (Life Sci) Vol. 60 Issue 19 Pg. 1651-8 ( 1997) ISSN: 0024-3205 [Print] Netherlands
• PMID: 9129120 (Publication Type: Journal Article)

Chemical References

• Analgesics
• Nicotine
• Verapamil
• Nifedipine

Topics

• Analgesics (pharmacology)
• Animals
• Male
• Nicotine (administration & dosage, pharmacology)
• Nifedipine (pharmacology)
• Pain Measurement
• Pain Threshold (drug effects)
• Rats
• Rats, Sprague-Dawley
• Verapamil (pharmacology)