Acetyl-L-Carnitine (ALC) represents the most abundant ester of carnitine presents in vertebrate central nervous system.

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ABSTRACT

Acetyl-L-Carnitine (ALC) represents the most abundant ester of carnitine presents in vertebrate central nervous system.

In the last years it has been observed that treatments with ALC produce various neuroprotective effects and there are many evidences that this substance has the capacity to reduce oxidative stress protecting the mitochondrial system from free radicals and lipid peroxidation.

ALC has neuromodulation property. In fact, it determines an increase of the synthesis and of the acetylcholine release. It is also able to modulate the dynamic synaptic structure, like showed in many behaviour studies on older rats, and to influence on the attention level, the learning and the memory.

Studies, performed in our laboratories, shows the ALC capacity to affect a non associative learning, in particular on the dishabituation of swim induction in the invertebrate Hirudo medicinalis,with long-term effects. These results suggest the ALC can exert its effects with gene expression changes.

In this thesis, we have conduced a molecular biology study: we have applied

the suppression subtractive hybridisation (SSH) to identified differentially

expressed genes using rats treated with ALC. The SSH permits to isolate

more rare transcripts than other techniques.

2 A group of rats has been intraperitoneally injected with a physiological solution (the control), whereas another group with 100mg/Kg body/weight of ALC (experimental group). The treatments has been performed daily for 21 days. RNA poli A

isolated from control and treated brain rats has been used in SSH method. We have constructed two library of cDNA: forward and reverse libraries.

The forward library contains positively transcripts ALC-induced and the reverse library contains the negatively ALC-modulated transcript. After

having evaluated substraction efficiency, cDNA was directly cloned and subjected to screening. Sequence of differential clones, obtained by automatic sequencer, has been analysed by comparison with sequences present in gene data bank using program such as FASTA, BLAST P, BLAST N.

Analysis of most interesting differentially expressed cDNA have showed identity with the coding sequences for “Prostaglandine D

synthetase”,

“Nudix” and “sodium dependent inorganic phosphate cotransporter”.

To confirme the really differentially expressed genes we have performed a

relative RT-PCR, with total RNA extracted from control and ALC treated

brain.