Altered expressions of VEGF mRNA splice variants during progression of uterine-peritoneal adhesions in the rat

PROBLEM: Postoperative pelvic adhesions contribute to infertility, pelvic p ain, bowel obstruction, and difficult reoperative procedures. METHOD OF STUDY: In the present study, a rat uterine-peritoneal adhesion mo del was developed to study the progression of adhesion formation during a c ourse of 7 days following pelvic surgery. The distal 1 cm of each uterine h orn and its adjacent peritoneum was abraded by six scratches with a scalpel blade, producing punctate bleeding. The scratched portion of uterine horn and the peritoneum was then held with Vicryl 3-0 to promote adhesion. The u terine tissue and the portion of peritoneum, held with suture, were then ex cised from a group of four rats, each at 6, 12, 24, 48, 72 hr and 5 and 7 d ays following surgery. Total RNA was isolated from these tissues and the ex pression pattern of different splice variants of vascular endothelial growt h factors (VEGF) was examined using relative abundance reverse transcriptas e polymerase chain reaction (RA-RT-PCR) method. RESULTS: Three known splice Variants of VEGF mRNA (VEGF(120), VEGF(164) and VEGF(188)), as well as an additional band (similar to 510 bp), were amplif ied from these tissues. The relative abundance of known VEGF isoforms demon strated altered expression during adhesion progression. When compared with noninjured uterine tissues, VEGF(120) and VEGF(188) demonstrated up-regulat ion during early stages of adhesion formation, whereas VEGF(164) rather dem onstrated down-regulation 24 and 48 hr following surgery. CONCLUSIONS: The up-regulation of VEGF isoforms during the progression of u terine-peritoneal adhesion may be a compensatory mechanism regulating angio genesis in order to provide nutrients and oxygen to the injured tissues.