Effect of somatostatin and its antagonist on morphine analgesia in mice.
OBJECTIVE
To study the effects of somatostatin (SST) and its antagonist cyclo-(7-aminoheptanoyl-Phe-D-Trp-Lys-Thr [Bzl]) (SSA) on morphine-induced analgesia.


METHODS
The pain assays were the hot plate and the tail flick test.


RESULTS
SST or SSA per se administered intracerebrally at the doses of 0.1 and 1 mg/mouse did not change the pain threshold of mice both in the hot plate and in the tail flick test. However, at the higher dose (10 mg/mouse), SST and SSA decreased the pain threshold in the tail flick test only. SST and SSA administered at the dose of 0.1 mg/mouse did not change morphine-induced analgesia. By contrast, SST and SSA at the doses of 1 and 10 mg/mouse reduced morphine analgesia effects both in the hot plate as well as in the tail flick test.


CONCLUSIONS
Our results indicate that SSA as well as SST may be useful in studying pain mechanisms.
Capasso
A
A
Department of Pharmaceutical Sciences, University of Salerno, Via Ponte Don Melillo 84084 Fisciano, Salerno, Italy. annacap@unisa.it
D000698:Analgesia; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006727:Hormone Antagonists / Q000494:pharmacology; D008297:Male; D051379:Mice; D009020:Morphine; D017288:Pain Threshold / Q000187:drug effects*; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000494:pharmacology*
D006727:Hormone Antagonists; D013004:Somatostatin; D009020:Morphine; C043820:cyclo(7-aminoheptanoylphenylalanyl-tryptophyl-lysyl-benzylthreonyl)