| 1. |
|
|
| 2. |
|
|
| 3. |
- Akyurek, L. M., et al.
(author)
-
Inhibition of transplant arteriosclerosis in rat aortic grafts by low molecular weight heparin derivatives
- 1995
-
In: Transplantation. ; 59:11, s. 1517-24
-
Journal article (peer-reviewed)abstract
- The effects of low molecular weight heparin derivatives with a low anticoagulant activity on transplant arteriosclerosis (TA) in a rat aortic transplant model were investigated. TA was induced by ischemia in the syngeneic transplants and primarily by immunological mechanisms in the allogeneic transplants. Treatment with the heparin derivatives, OAM 71262 or LA-heparin, was administered in a dosage of 250 micrograms/kg/hr by mini-osmotic pumps during 8 weeks. No immunosuppressive regimen was given to the recipient rats in either model. All rats were killed 8 weeks after aortic grafting. The grafts were examined for intimal and medial changes using an image analysis system. Heparin derivatives had a beneficial effect on both the intimal thickening and the medial injury in the syngeneic transplants, but not in the allogeneic grafts. In the syngeneic LA-heparin treated grafts, the thickness of the intima was less than that in the syngeneic control grafts (P < 0.05). In the syngeneic transplants, a significant increase was observed in the media after treatment with OAM 71262 (P < 0.01) as well as those with LA-heparin (P < 0.001). In the syngeneic grafts treated with both heparin derivatives, a significant reduction in the antigen expression of alpha-actin-containing smooth muscle cells in the intima, transforming growth factor-beta 1 both in the media and adventitia, and platelet-derived growth factor-beta receptors in the adventitia was observed immunohistochemically. In summary, low molecular weight heparin derivatives with low anticoagulant activity partially inhibited ischemia-induced syngeneic TA, whereas no such effect could be demonstrated in nonimmunosuppressed recipients with allogeneic grafts.
|
|
| 4. |
|
|
| 5. |
- Akyurek, M. L., et al.
(author)
-
Effects of angiopeptin on transplant arteriosclerosis in the rat
- 1995
-
In: Transpl Int. ; 8:2, s. 103-10
-
Journal article (peer-reviewed)abstract
- The influence of the somatostatin analogue angiopeptin on transplant arteriosclerosis was investigated using two aortic transplantation rat models. One was characterized by ischemia/reperfusion-induced changes in syngeneic transplants while immunologically induced changes dominated in the other allogeneic model. Angiopeptin, 100 micrograms/kg per day, was administered continuously until the sacrifice of the rats after 8 weeks. No additional immunosuppression was used in either model. An image analysis system was used to quantify the intimal and medial thicknesses of the grafts. In the syngeneic grafts, the intimal thickness was less than 50% of that of control grafts (P < 0.05), but no difference was seen in the allogeneic model. The expression of selected cells, TGF-beta s, and PDGF and PDGF alpha-receptors was detected immunohistochemically and displayed a similar picture in control and angiopeptin-treated grafts in both models. We conclude that angiopeptin has no clear immunosuppressive properties but may counteract ischemia-induced transplant arteriosclerosis.
|
|
| 6. |
|
|
| 7. |
- Akyurek, M. L., et al.
(author)
-
Expression of CD11b and ICAM-1 in an in vivo model of transplant arteriosclerosis
- 1995
-
In: Transpl Immunol. ; 3:2, s. 107-13
-
Journal article (peer-reviewed)abstract
- Adhesion molecules play a crucial role in transplant rejection in regulating the interaction of inflammatory cells with cells in the vascular wall. In an aortic transplantation model, we have previously analysed the early adhesion process (7.5 min to 24 h) and the impact of cold ischaemia time (1-24 h) upon transplant arteriosclerosis during the first 2 months after transplantation in the rat. The aim of this investigation was to study adhesion molecules in accelerated transplant arteriosclerosis in a rat model by analysing the immunohistochemical expression of CD11b and ICAM-1 up to 2 months and followed by a semiquantitative evaluation and multivariant analysis. Antigen expression of CD11b and ICAM-1 adhesion molecules was stronger in the aortic allografts than in the ischaemia-induced syngeneic aortic grafts in the whole vessel wall. Neither ICAM-1 nor CD11b antigen expression correlated significantly with time periods of ischaemia/reperfusion injury in allogeneic or syngeneic aortic transplants. CD11b and ICAM-1 are induced by allogeneic stimuli in transplanted aortas suggesting a role in the pathogenesis of transplant arteriosclerosis. Our findings have implications for understanding the role of cell adhesion activation in the vascular wall subject to chronic graft rejection.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
