The average time for onset of the analgesic effect for the three drugs were 18. 7± 10. 5, 19. 1± 8. 1and 12. 2±4. 6 minutes respectively and the average duration of the analgesic effect was 7. 2±2. 1,3. 6±1. 6 and 5. 8±2. 7 hours.
The average inhibitory duration of 9 pain-inhibited neurons decreased from (5.34±0.56) s to (2.41±0.89) s, the tail-flick latency was prolonged from (4.11±0.38) s to (8.01±0.59) s, i.e. displayed a analgesic effect of electroacupuncture.
The duration of analgesic effect in theexperimental group was significanly longer (376±842 sec) than that in the control group(2415 ± 380 sec) (P<0. 05).
Morphological Studies on the Relationship Between Primary Pain Afferent and the Changes of Ache Activity in the Spinal Cord of Rats During Electroacupuncture and Morphine Analgesia
Though only two esters showed antiinflammatory activity similar to that of the parent drug at equivalent dose levels, all the esters were equipotent to indomethacin in the mouse acetic acid-induced writhing assay for analgesic action.
Coadministration of the dipeptide and naloxone or naloxone methiodide insignificantly decreased the dipeptide analgesic effect in the tail-flick and acetic acid writing tests.
Introduction of an isopropyl residue into the C-terminal amide of the Nle2 analogue resulted in the appearance of anxiogenic and antialcohol activity and the ability to increase the morphine analgesic effect in the tail-flick test on rats.
Furthermore, the analgesic effect of IFN-α is reversible by monoclonal anti-IL-2 antibody.In vitro experiments show that IFN-α significantly increases the production of IL-2 in a dose dependent manner.
NMDA 0.05 μg or AMPA 0.05 μg decreased the pain threshold slightly but did not differ in effect compared with the aCSF group; 2 μg MK-801 or 0.5 μg NBQX both increased the pain threshold significantly.
Opioid receptors of μ, δ, and κ types are involved in the mechanisms of combined regulation of pain and immunity, with μ and δ receptors suppressing the immune response and κ receptors enhancing it.