Sameridine - intrathecal injection in the rat - Morphometric and morphologic analysis after chronic administration and effects on spinal cord blood flow
R. Karlsten et al., Sameridine - intrathecal injection in the rat - Morphometric and morphologic analysis after chronic administration and effects on spinal cord blood flow, ACT ANAE SC, 43(5), 1999, pp. 573-579
Citations number
23
Categorie Soggetti
Aneshtesia & Intensive Care","Medical Research Diagnosis & Treatment
Background: Sameridine is a type of compound with both local anaesthetic an
d analgesic effects with the clinical intention to be used intrathecally (I
T) in order to provide both surgical anaesthesia and prolonged postoperativ
e analgesia. Before new drugs are introduced for clinical use, they must be
tested for potential toxic effects.
Methods: In the present study sameridine (5 or 10 mg/ml), bupivacaine (5 mg
/ml) or saline (9 mg/ml) was injected intrathecally in rats twice, daily (a
t 07:00 and 19:00), 5 days a week for 2 weeks. Thereafter, the rats were an
aesthetised, perfused and the spinal cords were prepared for microscopic in
vestigation. A morphologic method, using light and electron microscopic exa
mination of the cross-section of the spinal cord, was combined with a quant
itative morphometric analysis of the number and size of neuronal cells in t
he dorsal horn as a sensitive indicator of neurotoxicity. Using the laser-D
oppler flowmetry technique, the effects of saline and sameridine (1, 5 and
10 mg/ml) on spinal cord blood flow (SCBF) was studied.
Results: No signs of neurotoxicity could be seen in any of the animals and
no significant differences were seen when comparing the cell number or cell
sizes in the groups injected with sameridine, bupivacaine or saline. After
IT administration of 10 mg/ml sameridine a significant, short-lasting, dec
rease in SCBF (72% of pre-drug value) was seen.
Conclusion: In conclusion, our studies do not show any signs of neurotoxic
effects of IT administration of sameridine in the rat. A transient decrease
in SCBF was noted after IT injection of sameridine 10 mg/ml.