TY - JOUR
T1 - Intrathecal dopamine and serotonin enhance motor and nociceptive blockades of lidocaine in rats
AU - Chiu, Chong Chi
AU - Liu, Kuo Sheng
AU - Wang, Jhi Joung
AU - Chen, Yu Wen
AU - Hung, Ching Hsia
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/9/25
Y1 - 2023/9/25
N2 - The study examined the effect of intrathecal injection of dopamine (serotonin) and/or lidocaine. Intrathecal injections of dopamine (serotonin or epinephrine), lidocaine, or their combination were carried out in male Sprague Dawley rats. Neurobehavioral examinations (motor and nociceptive reactions) were performed before and after spinal injection. Intrathecal serotonin (1.5 μmol), dopamine (2.5 μmol), epinephrine (1:40000), and lidocaine (0.75 μmol) produced 29%, 33%, 29%, and 54% nociceptive blockade, whereas serotonin (1.5 μmol), dopamine (2.5 μmol), or epinephrine (1:40000) produced a longer duration of nociceptive blockade than lidocaine (0.75 μmol) (P < 0.05). Serotonin (1.5 μmol), dopamine (1.25 and 2.5 μmol), or epinephrine (1:40000 and 1:80000) prolonged the duration and increased the potency of spinal motor and nociceptive blockades of lidocaine (50% effective dose, ED50) (P < 0.05). The motor and nociceptive blockades caused by lidocaine (ED50) plus dopamine (2.5 μmol) or lidocaine (ED50) plus epinephrine (1:40000) were more outstanding than lidocaine (ED50) plus serotonin (0.75 μmol) (P < 0.05). Our study provides evidence that intrathecal dopamine or serotonin produces spinal nociceptive blockade dose-dependently. Dopamine and serotonin are less potent than lidocaine in inducing spinal nociceptive blockade. When mixed with lidocaine solution, dopamine or serotonin improves spinal motor and nociceptive blockades. The motor and nociceptive blockade caused by lidocaine (ED50) plus dopamine (2.5 μmol) is similar to that caused by lidocaine (ED50) plus epinephrine (1:40000).
AB - The study examined the effect of intrathecal injection of dopamine (serotonin) and/or lidocaine. Intrathecal injections of dopamine (serotonin or epinephrine), lidocaine, or their combination were carried out in male Sprague Dawley rats. Neurobehavioral examinations (motor and nociceptive reactions) were performed before and after spinal injection. Intrathecal serotonin (1.5 μmol), dopamine (2.5 μmol), epinephrine (1:40000), and lidocaine (0.75 μmol) produced 29%, 33%, 29%, and 54% nociceptive blockade, whereas serotonin (1.5 μmol), dopamine (2.5 μmol), or epinephrine (1:40000) produced a longer duration of nociceptive blockade than lidocaine (0.75 μmol) (P < 0.05). Serotonin (1.5 μmol), dopamine (1.25 and 2.5 μmol), or epinephrine (1:40000 and 1:80000) prolonged the duration and increased the potency of spinal motor and nociceptive blockades of lidocaine (50% effective dose, ED50) (P < 0.05). The motor and nociceptive blockades caused by lidocaine (ED50) plus dopamine (2.5 μmol) or lidocaine (ED50) plus epinephrine (1:40000) were more outstanding than lidocaine (ED50) plus serotonin (0.75 μmol) (P < 0.05). Our study provides evidence that intrathecal dopamine or serotonin produces spinal nociceptive blockade dose-dependently. Dopamine and serotonin are less potent than lidocaine in inducing spinal nociceptive blockade. When mixed with lidocaine solution, dopamine or serotonin improves spinal motor and nociceptive blockades. The motor and nociceptive blockade caused by lidocaine (ED50) plus dopamine (2.5 μmol) is similar to that caused by lidocaine (ED50) plus epinephrine (1:40000).
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U2 - 10.1016/j.neulet.2023.137473
DO - 10.1016/j.neulet.2023.137473
M3 - Article
C2 - 37689343
AN - SCOPUS:85170428250
SN - 0304-3940
VL - 814
JO - Neuroscience Letters
JF - Neuroscience Letters
M1 - 137473
ER -