Abstract
Vasoactive intestinal polypeptide (VIP) has numerous regulatory roles in peripheral, endocrine organs and in the central nervous system. The present study related to the effects of centrally (intracerebroventricularly) administered VIP on pain sensitivity and on opiate tolerance and dependence in intact male CFLP mice. VIP was analgesic when administered alone centrally. Naloxone treatment abolished this analgesic effect. VIP decreased the analgesic effect of a single subcutaneous morphine injection and the development of chronic tolerance to morphine. Morphine withdrawal signs were not significantly affected after VIP pretreatment. These findings indicate that VIP may play a role in pain sensitivity and that an opiate component may participate in this effect.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Analgesics, Non-Narcotic / administration & dosage
-
Analgesics, Non-Narcotic / pharmacology*
-
Analgesics, Opioid / administration & dosage
-
Analgesics, Opioid / adverse effects
-
Analgesics, Opioid / antagonists & inhibitors*
-
Animals
-
Drug Tolerance
-
Injections, Intraventricular
-
Male
-
Mice
-
Mice, Inbred Strains
-
Morphine / administration & dosage
-
Morphine / adverse effects
-
Morphine / antagonists & inhibitors*
-
Naloxone / pharmacology
-
Narcotic Antagonists / pharmacology
-
Pain Measurement / drug effects
-
Substance Withdrawal Syndrome / psychology
-
Vasoactive Intestinal Peptide / administration & dosage
-
Vasoactive Intestinal Peptide / pharmacology*
Substances
-
Analgesics, Non-Narcotic
-
Analgesics, Opioid
-
Narcotic Antagonists
-
Naloxone
-
Vasoactive Intestinal Peptide
-
Morphine