کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1907524 | 1046369 | 2006 | 6 صفحه PDF | دانلود رایگان |

The molecular mechanisms by which capillary supply is maintained with advancing age remain to be elucidated. To help clarify these mechanisms, we investigated the gene expression levels of angiogenesis-related factors in young (2.5-month-old), adult (6-month-old), and old (22-month-old) mice. To assess the capillary supply, the capillary endothelium in frozen transverse sections was identified by staining for alkaline phosphatase. The mRNA levels for angiogenesis-related factors were analyzed using real-time RT-PCR. The capillary supply to individual muscle fibers, assessed as the number of capillaries around a muscle fiber, did not change with advancing age. Real-time RT-PCR analysis showed that (1) the level of mRNA for VEGF was lower in old animals than young animals; (2) the mRNA levels of Flt-1 and neuropilin-1 are lower in old animals than young animals, while that of KDR/Flk-1 remained unchanged with advancing age; and (3) the levels of mRNA for angiopoietin-1 and -2 remained unchanged, while the mRNA for Tie-2 was lower in old animals than young animals. These findings suggest that capillary supply is maintained irrespective of the down-regulation of several angiogenesis-related factors and that old animals possess the minimum levels of maintenance and reparative abilities needed to preserve the capillary supply.
Journal: Experimental Gerontology - Volume 41, Issue 1, January 2006, Pages 49–54