[The effect of beta-casomorphin-7 on the level of food and defense motivations in different types of learning]. / Vliianie beta-kazomorfina-7 na uroven' pishchevoi i oboronitel'noi motivatsii pri razlichnykh vidakh obucheniia.

The effects of intraperitoneal administration of the heptapeptide beta-casomorphin-7 (beta-C-7) on learning were investigated in white rats using T-maze, active and passive avoidance tests. The substance injected in the dose of 5 mg/kg 5 min prior to training accelerated the acquisition of food-reinforced task increasing the number of correct trials in T-maze. The same injection in the dose of 1 mg/kg impaired the acquisition of avoidance tasks. The heptapeptide didn't influence food motivation and consolidation of memory trace. The data obtained support the idea that beta-C-7 attenuated manifestations of defensive motivation.

[The behavioral effects of beta-casomorphin-7 and its des-Tyr analogs]. / Povedencheskie éffekty beta-kazomorfina-7 i ego dez-Tyr-analogov.

The effects of intraperitoneal administration of the heptapeptide beta-casomorphin-7 (beta-K-7) and its des-Tyr analogues (beta-K-6 and beta-K-4) on spontaneous locomotor activity were investigated in rats using "Opto-Varimax", "RODEO-2" and "open field" tests. At 20 mg/kg 5 minutes prior to the beginning of measurements beta-K-7 produced a significant decrease in linear locomotion and rearing. As for beta-K-6 and beta-K-4, their influence on locomotion of the experimental animals was less evident. In contrast to beta-K-7, its des-Tyr analogues (20 mg/kg) produced a marked decrease in nose-poking behavior. Beta-K-7 in doses that had no effect on spontaneous behaviour (1 and 5 mg/kg) attenuated extreme behavioural displays under stress conditions. The experimental results suggest the advisability of further investigations of neurotropic properties of beta-K-7 and related peptides.

[Effects of systemically-administered beta-casomorphin-7 on nociception in rats]. / Deistvie beta-kazomorfina-7 na notsitseptsiiu krys pri sistemnom vvedenii.

The influence of food-derived heptapeptide beta-casomorphin-7 (beta-CM-7) on pain sensibility of white rats was studied by tail flick test. As shown for doses 10 and 20 mg/kg intraperitoneally, injected beta-CM-7 induced significant analgesia; lower peptide concentration (5 mg/kg) was ineffective. As a whole, there is a significant positive correlation between the intensity of analgesia and the quantity of administered exorphine. These changes of pain sensibility were observed for one hour after injection of heptapeptide; further measurements showed no significant difference of time reaction between control and experimental groups of rats. It was found out that animals with high native level of pain sensibility (4-8 sec) made the main contribution to manifestation of analgesia.