The effect of peptide bioregulators on the resistance of rats to cold-stress factor

BACKGROUND: Biologically active regulatory peptides are the drugs of new type that act selectively on targets, with having no significant side effects. AIM: The aim of the study was to study the potential effect of peptide preparations Cortexin® and Semax® on the resistance of the rat organism to the cold stress factor in the model of cold stress maladaptation. MATERIALS AND METHODS: White outbred male rats were injected intraperitoneally twice daily with placebo (n = 30), Cortexin® 5 mg/kg (n = 30) or Semax® 0.3 mg/kg (n = 30). Three days after the start of the injection course, the cold-stress effect was simulated in the climate chamber (Feutron, Germany) by cooling the air to 5°C at a relative humidity of 75–80%. RESULTS: The use of RP significantly increased the duration of the rectal temperature plateau-period within 35°C (moderate hypothermia): in animals of the Cortexin® group from 10 days to 12 days, and in animals of the Semax® group, from 10 to 14 days. Cortexin® demonstrated moderate immunomodulatory properties, and Semax® had a more pronounced immunomodulatory effect. Both preparations showed a stress-protective effect. The use of regulatory peptides provided to delay the decrease in the rat general motor activity and exploratory behavior which develops under the influence of a simulated cold-stress factor. A slower rate of decrease in the swimming time of rats under the influence of regulatory peptides was registrated. CONCLUSIONS: The meteoadaptogenic, stress-protective and nootropic effects of the regulatory peptides Cortexin® and Semax® were confirmed in rats on the model of cold-stress maladaptation.