TY - JOUR
T1 - Intrathecal somatostatin in cat and mouse studies on pain, motor behavior, and histopathology
AU - Gaumann, D. M.
AU - Yaksh, T. L.
AU - Wilcox, G. L.
AU - Rodriguez, M.
PY - 1989
Y1 - 1989
N2 - Effects of intrathecal (i.t.) somatostatin (SST) on nociception, motor function, and spinal cord pathology were evaluated in cats and mice. Cats chronically implanted with i.t. lumbar catheters received either a single injection of 2 mg SST i.t. (group I, N = 4), four repetitive injections on consecutive days of 2 mg SST i.t. (group II, N = 4) or saline i.t. (group III, N = 2). No analgesic effects were observed following single or repeated SST injections as evaluated by the skin twitch response. However, significant impairment of hind leg motor function ranging from unbalanced gait to paralysis was observed following the first SST i.t. injection. Histological examination of spinal cords six days after the first SST injection in group II showed multiple pyknotic neurons in all cats. Some cats showed focal demyelination in the posterior column of the spinal cord white matter. Mice received a single percutaneous injection of 50 μg SST i.t. (group I, N = 7), 5 μg SST i.t. (group II, N = 3), or saline i.t. (group III, N = 5). No analgesic effects were observed in groups II and III as evaluated by the hot plate (HP) and tail flick (TF) tests. Injection of 50 μg SST i.t. (group I) caused reversible flaccid hind leg paralysis in all mice and concomitant increases in HP and TF latencies. Histologic examination revealed focal demyelination in the spinal cord in three out of seven mice in this group. Present data substantiate neurotoxic effects of i.t. SST and lack of behaviorally defined antinociception at innocuous dosages.
AB - Effects of intrathecal (i.t.) somatostatin (SST) on nociception, motor function, and spinal cord pathology were evaluated in cats and mice. Cats chronically implanted with i.t. lumbar catheters received either a single injection of 2 mg SST i.t. (group I, N = 4), four repetitive injections on consecutive days of 2 mg SST i.t. (group II, N = 4) or saline i.t. (group III, N = 2). No analgesic effects were observed following single or repeated SST injections as evaluated by the skin twitch response. However, significant impairment of hind leg motor function ranging from unbalanced gait to paralysis was observed following the first SST i.t. injection. Histological examination of spinal cords six days after the first SST injection in group II showed multiple pyknotic neurons in all cats. Some cats showed focal demyelination in the posterior column of the spinal cord white matter. Mice received a single percutaneous injection of 50 μg SST i.t. (group I, N = 7), 5 μg SST i.t. (group II, N = 3), or saline i.t. (group III, N = 5). No analgesic effects were observed in groups II and III as evaluated by the hot plate (HP) and tail flick (TF) tests. Injection of 50 μg SST i.t. (group I) caused reversible flaccid hind leg paralysis in all mice and concomitant increases in HP and TF latencies. Histologic examination revealed focal demyelination in the spinal cord in three out of seven mice in this group. Present data substantiate neurotoxic effects of i.t. SST and lack of behaviorally defined antinociception at innocuous dosages.
KW - Hormones, somatostatin
KW - Pain, experimental
KW - Spinal cord, neurotoxicity
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U2 - 10.1213/00000539-198905000-00015
DO - 10.1213/00000539-198905000-00015
M3 - Article
C2 - 2566288
AN - SCOPUS:0024807188
SN - 0003-2999
VL - 68
SP - 623
EP - 632
JO - Anesthesia and analgesia
JF - Anesthesia and analgesia
IS - 5
ER -