Related Experiment Video
Updated: Oct 11, 2026

Analysis of Raw and Processed Cyperi Rhizoma Samples Using Liquid Chromatography-Tandem Mass Spectrometry in Rats with Primary Dysmenorrhea
Published on: December 23, 2022
Pindolol, a beta-adrenoceptor blocker/5-hydroxytryptamine(1A/1B) antagonist, enhances the analgesic effect of
Olga M Rojas-Corrales1, Antonio Ortega-Alvaro, Juan Gibert-Rahola
1Department of Neuroscience, Neuropsycopharmacology Unit, University of Cádiz, Plz. Fragela 9, 11003 Cádiz, Spain.
Abstract:
The ability of pindolol, a beta-adrenoceptor blocker/5-hydroxytryptamine(1A/1B) antagonist, to enhance the clinical antidepressant response to selective serotonin re-uptake inhibitors is generally attributed to a blocking of the feedback that inhibits the serotoninergic neuronal activity mediated by somatodendritic 5-hydroxytryptamine (5-HT)(1A) autoreceptors. The current study examined the ability of pindolol to enhance the analgesic effect of tramadol, an atypical centrally-acting analgesic agent with relatively weak opioid receptor affinity and which, like some antidepressants, is able to inhibit the re-uptake of 5-HT in the raphe nuclei. Racemic pindolol (2 mg/kg, s.c.), rendered analgesic a non-effective acute dose of tramadol (10-40 mg/kg, i.p.) in two nociceptive tests: a hot plate test in mice and a plantar test in rats. Moreover, (+/-)8-OH-DPAT (0.125-1 mg/kg, s.c.), a selective 5-HT(1A) agonist, reduces the analgesic effect of tramadol in the same tests. These results suggest an implication of the somatodendritic 5-HT(1A) receptors in the analgesic effect of tramadol and open a new adjuvant analgesic strategy for the use of this compound.
Related Concept Videos
Opioid Analgesics: Synthetic and Semisynthetic Opioids
Analgesia and Pain Management
Adrenergic Antagonists: ɑ and β-Receptor Blockers
Sedatives and Hypnotics Drugs: Miscellaneous Agents
Melatonin congeners like ramelteon (Rozerem) and tasimelteon (Hetlioz) selectively bind to melatonin receptors (MT1 and MT2) and thus mimic the actions of melatonin, a hormone that regulates sleep-wake cycles. Tasimelteon is primarily used for non-24-hour sleep-wake disorder, common in blind patients. They are also used to treat conditions like insomnia...
Drugs Affecting Neurotransmitter Release or Uptake
Opioid Analgesics: Morphine and Other Natural Cogeners