A cDNA encoding the rat homolog of the previously characterized murine endozepine-like peptide (ELP) was isolated by a PCR cloning strategy. Sequence comparison with the murine cDNA sequence revealed a conservation of the ELP primary structure between both rodent species with minor amino acid exchanges. We investigated the genomic organization of the rat ELP gene by genomic PCR. This indicated the presence of a single short intron of 451bp interrupting the 5' untranslated region. Tissue-dependent ELP expression was determined by Northern hybridization and semiquantitative RT-PCR. Northern hybridization showed an ELP specific transcript in both the male and the female gonad, but the level of ovarian ELP transcription was considerably lower than in the testis. RT-PCR analysis demonstrated a low and varying level of ELP background expression in all examined tissues. In contrast to the closely related ACBP gene, ELP shows a different genomic organization and a more regulated expression pattern, and may exert a specific function as a gonadal acyl-CoA pool former and transporter.