TY - JOUR
T1 - Intrathecal oxotremorine affects formalin-induced behavior and spinal nitric oxide synthase immunoreactivity in rats
AU - Przewlocka, B.
AU - Mika, J.
AU - Capone, F.
AU - Machelska, H.
AU - Pavone, F.
PY - 1999/3
Y1 - 1999/3
N2 - The present research was undertaken to investigate, by behavioral and immunohistochemical methods, the effects of intrathecal (ITH) injection of the muscarinic agonist oxotremorine on the response to the long-lasting nociceptive stimulus induced by injection of formalin into the rat hind paw. Formalin injection induced a biphasic, pain-induced behavioral response (paw jerks), as well as an increase in the number of nitric oxide (NO) synthase-labeled neurons in laminae I-III, IV, and X, but not in laminae V-VI. Oxotremorine (0.1-10 ng, ITH) inhibited paw-jerk frequency in both phases of formalin-induced behavior. The immunohistochemical results showed that ITH-injected oxotremorine differently affected the level of NO synthase in lumbar part of the spinal cord: no change or increase after the dose of 1 ng, and a significant reduction of nitric oxide synthase neurons after the higher dose (10 ng). These results evidenced a role of cholinergic system in the modulation of tonic pain and in nitric oxide synthase expression at the spinal cord level, which further suggests that these two systems could be involved in phenomena induced by long-lasting nociceptive stimulation. Copyright (C) 1999 Elsevier Science Inc.
AB - The present research was undertaken to investigate, by behavioral and immunohistochemical methods, the effects of intrathecal (ITH) injection of the muscarinic agonist oxotremorine on the response to the long-lasting nociceptive stimulus induced by injection of formalin into the rat hind paw. Formalin injection induced a biphasic, pain-induced behavioral response (paw jerks), as well as an increase in the number of nitric oxide (NO) synthase-labeled neurons in laminae I-III, IV, and X, but not in laminae V-VI. Oxotremorine (0.1-10 ng, ITH) inhibited paw-jerk frequency in both phases of formalin-induced behavior. The immunohistochemical results showed that ITH-injected oxotremorine differently affected the level of NO synthase in lumbar part of the spinal cord: no change or increase after the dose of 1 ng, and a significant reduction of nitric oxide synthase neurons after the higher dose (10 ng). These results evidenced a role of cholinergic system in the modulation of tonic pain and in nitric oxide synthase expression at the spinal cord level, which further suggests that these two systems could be involved in phenomena induced by long-lasting nociceptive stimulation. Copyright (C) 1999 Elsevier Science Inc.
KW - Cholinergic antinociception
KW - Formalin pain
KW - Nitric oxide synthase
KW - Oxotremorine
KW - Rats
KW - Spinal nociception
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U2 - 10.1016/S0091-3057(98)00176-2
DO - 10.1016/S0091-3057(98)00176-2
M3 - Article
C2 - 10080247
AN - SCOPUS:0033017454
VL - 62
SP - 531
EP - 536
JO - Pharmacology Biochemistry and Behavior
JF - Pharmacology Biochemistry and Behavior
SN - 0091-3057
IS - 3
ER -