Molecular biological characterization of phosphodiesterase 3A from human corpus cavernosum

The hydrolysis of the second messenger cyclic AMP (cAMP) by phosphodiestera se 3 (PDE3) is known to play an important regulatory role in the context of relaxation of cavernous smooth muscle of the penis. Thus, we investigated the PDE3A isoform from penile cavernous tissues of male patients with and w ithout symptoms of erectile dysfunction at the molecular biological level. As revealed by reverse transcriptase polymerase chain reaction, of all tiss ues of the urogenital tract analyzed the expression of the PDE3A gene was h ighest in the corpus cavernosum However, significant differences in the lev els of gene expression were not found between the two subgroups of patients . Also, the determined nucleotide sequences of the cloned penile PDE3A cDNA s of all patients were absolutely identical. Surprisingly, some deviations could be detected in the cDNA sequences of PDE3A from human myocard and pla telets. The data obtained indicate that neither the expression levels nor t he sequence deviations of PDE3A are the main reasons for erectile dysfuncti on in men. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.