changes in expression of platelet derived growth factor [PDGF] and PDGF receptor in rat corpus cavernosum after exposure to in vivo hypoxia and cigarette smoking

ABSTRACT

Platelet derived growth factor [PDGF] over activity has been implicated in atherosclerosis and several fibrotic conditions including lung and kidney fibrosis, liver cirrhosis and myelofibrosis. Low oxygen tension [hypoxia] and cigarette smoking is a known stimulus for transcriptional induction of [PDGF] ligand and receptor gene. We studied the expression of [PDGF-A] and [PDGFR-beta] in adult male rat isolated corpus cavernosum under hypoxic and cigarette smoking conditions being associated with induction of fibrosis which may lead to erectile dysfunction. Fifty adult male albino rats were used in this experiment. They were divided into 5 groups. Group I [n=10], served as control group. Group II [n=10] rats exposed to acute hypoxia. Group III [n=10] rats exposed to chronic hypoxia. Group IV [n=10] rats exposed to acute cigarette smoking. Group V [n=10] rats exposed to chronic cigarette smoking. In all groups at the end of each experiment corpora cavernosa of all rats were carefully dissected and freed from surrounding tunica albuginia then frozen in -80°C for subsequent reverse transcriptase polymerase chain reaction [RT-PCR]. In all groups of rats PDGF-A and PDGR-m RNA were measured. There was significant increase in PDGF-A mRNA and PDGF- beta receptor in acute hypoxic group, chronic hypoxic group, and chronic cigarette smoking groups of rats compared to control group. It was found that hypoxia, whether, acute or chronic have similar effect of increasing PDGF-A mRNA and PDGF-beta receptor as well as chronic cigarette smoking group of rats. This may lead to erectile dysfunction