TY - JOUR
T1 - Effects of a novel neurotensin peptide analog given extracranially on CNS behaviors mediated by apomorphine and haloperidol
AU - Cusack, Bernadette
AU - Boules, Mona
AU - Tyler, Beth M.
AU - Fauq, Abdul
AU - McCormick, Daniel J.
AU - Richelson, Elliott
N1 - Funding Information:
This work was funded by grant MH 27692 from the National Institute of Mental Health, by the Mayo Foundation for Medical Education and Research, and the Forrest C. Lattner Foundation.
PY - 2000
Y1 - 2000
N2 - Neurotensin (NT) is a neuropeptide neurotransmitter in the central nervous system. It has been implicated in the therapeutic and in the adverse effects of neuroleptics. Activity of NT in brain can only be shown by direct injection of the peptide into that organ. However, we have developed a novel analog of NT(8-13), NT69L, which is active upon intraperitoneal (i.p.) injection. Like atypical neuroleptics, NT69L blocked the climbing behavior in rats, but not the licking and sniffing behaviors of a high dose (600 μg/kg) of the non-selective dopamine agonist apomorphine. Its blockade of climbing was very potent with an ED50 (effective dose at 50% of maximum) of 16 μg/kg. Both apomorphine and NT69L caused a long-lasting hypothermia, which was greater with the peptide but not synergistic in combination with apomorphine. The ED50 of NT69L for hypothermia was 390 μg/kg. NT69L (up to 5 mg/kg i.p.) did not produce catalepsy. However, when given before haloperidol, NT69L, but not clozapine, completely prevented catalepsy. When given after haloperidol, NT69L, but not clozapine, reversed haloperidol's cataleptic effects with an ED50 of 260 μg/kg. There was no significant difference between the ED50s for hypothermia and anticataleptic effects of NT69L. However, the ED50 for blocking the effects of apomorphine was significantly lower than the other two. These data suggest that NT69L may have neuroleptic properties in humans and may be useful in the treatment of extrapyramidal side effects caused by typical neuroleptics such as haloperidol. Copyright (C) 2000 Elsevier Science B.V.
AB - Neurotensin (NT) is a neuropeptide neurotransmitter in the central nervous system. It has been implicated in the therapeutic and in the adverse effects of neuroleptics. Activity of NT in brain can only be shown by direct injection of the peptide into that organ. However, we have developed a novel analog of NT(8-13), NT69L, which is active upon intraperitoneal (i.p.) injection. Like atypical neuroleptics, NT69L blocked the climbing behavior in rats, but not the licking and sniffing behaviors of a high dose (600 μg/kg) of the non-selective dopamine agonist apomorphine. Its blockade of climbing was very potent with an ED50 (effective dose at 50% of maximum) of 16 μg/kg. Both apomorphine and NT69L caused a long-lasting hypothermia, which was greater with the peptide but not synergistic in combination with apomorphine. The ED50 of NT69L for hypothermia was 390 μg/kg. NT69L (up to 5 mg/kg i.p.) did not produce catalepsy. However, when given before haloperidol, NT69L, but not clozapine, completely prevented catalepsy. When given after haloperidol, NT69L, but not clozapine, reversed haloperidol's cataleptic effects with an ED50 of 260 μg/kg. There was no significant difference between the ED50s for hypothermia and anticataleptic effects of NT69L. However, the ED50 for blocking the effects of apomorphine was significantly lower than the other two. These data suggest that NT69L may have neuroleptic properties in humans and may be useful in the treatment of extrapyramidal side effects caused by typical neuroleptics such as haloperidol. Copyright (C) 2000 Elsevier Science B.V.
KW - Atypical neuroleptics
KW - Catalepsy
KW - Neurotensin receptor
KW - Peptide analogs
KW - Subtype 1
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U2 - 10.1016/S0006-8993(99)02363-X
DO - 10.1016/S0006-8993(99)02363-X
M3 - Article
C2 - 10677610
AN - SCOPUS:0033975962
SN - 0006-8993
VL - 856
SP - 48
EP - 54
JO - Brain Research
JF - Brain Research
IS - 1-2
ER -