Cryoprotective Characteristics of L-Carnosine Dipeptide (Β-Alanyl-L-Histidine)

Abstract: Dipeptide (β-alanyl-L-histidine) has been found in significant amounts in muscle and brain mammals, especially in olfactory structures. L-carnosine exhibits many protective effects under the action of various cytotoxic factors on cells. We used slices of the olfactory cortex of rats to study the cryoprotective characteristic of L-carnosine in the process of cryopreservation (CP). Changes were analyzed in the activity of N-methyl-D-aspartate (NMDA) receptors (NMDARs) when registering NMDA potentials caused by electrical stimulation of the lateral of olfactory tract. The brain slices were preincubated with L-carnosine (20 mM) in an artificial cerebral solution, frozen (–10°C), and after prolonged CP (30 days) warmed up to 37°C. Before and after CP, changes were determined in the amplitudes of NMDA potentials. Dipeptide was found to optimize the pH of a freezing solution after CP and retained the activity of NMDARs determined by the amplitude of NMDA potentials. After CP, L-carnosine contributed to the dehydration of excess free water from slices. The dipeptide inhibited the development of glutamate excitotoxicity in brain slices during CP and maintained the normal functioning of NMDARs. The obtained data prove that L-carnosine exhibits the properties of an endogenous cryoprotector in the nervous tissue. © 2023, Pleiades Publishing, Ltd.