PT  - JOURNAL ARTICLE
AU  - F Betoin
AU  - D Ardid
AU  - A Herbet
AU  - O Aumaitre
AU  - J L Kemeny
AU  - P Duchene-Marullaz
AU  - J Lavarenne
AU  - A Eschalier
TI  - Evidence for a central long-lasting antinociceptive effect of vapreotide, an analog of somatostatin, involving an opioidergic mechanism.
DP  - 1994 Apr 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 7--14
VI  - 269
IP  - 1
4099  - http://jpet.aspetjournals.org/content/269/1/7.short
4100  - http://jpet.aspetjournals.org/content/269/1/7.full
SO  - J Pharmacol Exp Ther1994 Apr 01; 269
AB  - The antinociceptive effect of the octapeptide vapreotide, an analog of somatostatin, was studied after systemic injection in normal mice using the hot plate and abdominal stretching assays, and in normal rats using the paw pressure analgesiometric assay. Vapreotide was ineffective at 1 microgram/kg s.c. in the hot plate test in mice, but 30 min after injection it induced an antinociceptive effect at s.c. injected doses of 8, 64, 512 and 4096 micrograms/kg, with an ED50 of 213 +/- 5 micrograms/kg. For the three highest doses this effect persisted 24 hr after the injection (maximal increase: +80 +/- 23% for 512 micrograms/kg) and disappeared at 48 hr. In the phenylbenzoquinone stretching test, in mice, the ED50 was 186 +/- 6 micrograms/kg (maximal decrease: -63 +/- 5%); the effect persisted 24 hr only for the same two highest doses. Using the paw pressure test, in rats, a dose-dependent increase in paw withdrawal and vocalization thresholds was observed for 21 and 24 hr, respectively, after s.c. injections of 16, 64 and 512 micrograms/kg. Global scores obtained for vocalization thresholds were significantly increased (vs. paw withdrawal thresholds) for 64 and 512 micrograms/kg. Carrageenan-induced nociception in rats was reduced for 21 hr by 64 and 512 micrograms/kg s.c.; scores of the contralateral noninflamed paw were also increased. Vapreotide administered locally in the inflamed paw was inactive. No change in edema volume was obtained after systemic injection of vapreotide.(ABSTRACT TRUNCATED AT 250 WORDS)