Experimental Study Of Morphology On The Improvement Of Revascularization By VEGF And Its Expreession Vector In TMP Models

Experimental study of morphology on the improvement of rcvascularization by VEGF and its expression vector in TMR models PhD.Student: Zhang Xiaodong Tutor: Xu Dachuan Professor Liu Xiaocheng* Professor Dept. Of Anatomy, The First Military Medical University Guangzhou 510515 *Dept. of cardiac surgery, PUMC Hospital, CAMS and PUMC, Beijing 100730 ABSTRACT The basic study for transmyocardial revascularization by laser (TMLR) has developed rapidly, and has already applied to clinical practice. However, the clinical results is not satisfactory, there are various opinions about it. Different opinions and contradictions still exist , especially on the morphological changes of laser channels; on the angiogenesis and revascularization after TMLR; on the clinical effect and the prospect for clinical appliance etc. Many basic problems have not been solved, basic study apparently lags behind clinical practice. With the rapid development of molecular biology and techniques of gene engineering in recent years, it presents a new prospect for further experimental study and clinical appliance of TMR. Only simple TMLR was used in the past, now we create machine TMR while using simple TMR in our study. In addition, we used VEGF and VEGFcDNA plasmid in myocardial channels, which improves angiogenesis and reduces fibrosis in channels, therefore it provides experimental base of morphology and technical preparation for clinical appliance of TMR and for studying morphological evidence and mechanism of angiogenesis in the channels. Material and methods 1. Used 30 adult rabbits as Group A. Irradiated left ventricular wall of the heart with CO2 Laser, forming transmyocardial laser channels. Observed morphological structures of blood vessels and fibrotic connective tissue and changing pattern, with the methods of histology and pathology at different periods after operation. 2. Used 24 adult rabbits as Group B. Used machine drill which is empty -5- inside for TMR on left ventricular wall and compared with Group A on histology at different periods after operation. Compared group A with group B on amount/density of new blood vessels and the fibrosis width of the channels in order to find out the better method for TMR. 3. 40 adult rabbits, 20 as Group C, 20 as Group D. After laser TMR and machine TMR on each group, VEGFI was injected in the channels of two groups. Observed the effect of VEGF on angiogonesis and the morphological changes such as the extent of fibrosis in the channels of two groups, including histological comparation between Group c and Group D, Group C/D and Group A/B. At the same time, Search for more effective comprehensive techniques and methods for TMR combining molecular biological techniques to improve angiogenesis and revascularization in the channels. 4. 24 adult rabbits, as Group E. After machine TMR, VEGFcDNA plasmids was injected in machir~e channels. Observed histological structures between group E and group A/B/C/D at different periods after operation. Observed the effects of plasmids expression on the angiogenesis and fibrosis in channels by comparing the amount/density of new blood vessels and structures. Proved experimental basis on morphology for TMR combined with gene...