Changes in the Anatomic and Microscopic Structure and the Expression of HIF-1α and VEGF of the Yak Heart with Aging and Hypoxia - Fig 3

<p>A: The diameter of collagen fiber. B: The optical density of collagen fiber.</p

Enzymatic activities of Complex I-V of mitochondria.

<p>Unit: nmoles/min/mg protein.</p

The weight of heart and yak, and the length of heart perimeter.

<p>The weight of heart and yak, and the length of heart perimeter.</p

Thickness of the ventricular wall of heart in yak.

<p>Unit: cm.</p

Immunogold labeling of HIF-1α and VEGF protein in the yak heart.

<p>A: Electron microscope images showing HIF-1α immunopositive silver grains in endothelial cells (arrowheads). B: HIF-1α immunopositive silver grains in cardiac muscle cells. C: No HIF-1α immunopositive silver grains in smooth muscle cells. D: Electron microscope images showing VEGF immunopositive silver grains in smooth muscle cells. E: VEGF immunopositive silver grains in endothelial cells (arrowheads). F: High magnification of VEGF immunopositive silver grains in endothelial cells (arrowheads). G: Some fine filaments were found in smooth muscle cells (boxed area). H: Smooth muscle cell has a higher electron density than endothelial cells. I, J: No gold particles were found in control sections. SMC: smooth muscle cell, EC: endothelial cell, EF: elastic fiber, SEF: secondary elastic fiber.</p

HIF-1α and VEGF protein expression in the yak heart were measured by ELISA.

<p>A: HIF-1α expression. B: VEGF expression.</p

Thickness of vascular intima and tunicae media vasorum inrami anterior descendens, left and right circumflex of coronary artery.

<p>Unit: μm.</p

Immunohistochemical localization of HIF-1α protein in the yak heart.

<p>A, B, C, D, E: A strong positive immunostaining of HIF-1α protein in endothelial cells of coronary arterial in 1 days, 6 months, 1 year, 2 years and 5 years old yak, respectively. G: A strong positive immunostaining of HIF-1α protein in cardiac muscle cells. F, H: Control of HIF-1α expression in the coronary arterial and myocardium.</p

The microscope structures of coronary artery.

<p>A: A monolayer of endothelial cell adhered to internal elastic membrane in 1-day old yak (arrowheads) (Massion trichrome). B: An integral structure of the left circumflex of coronary artery in 1-day old yak (Massion trichrome). C: Internal elastic membrane was disrupted in heart of 6-month old yak (arrowheads) (VVG). D: The internal elastic membrane was divided into two layers in 1-year old yak (arrowheads) (VVG). E: Those internal elastic membrane and smooth muscle cells together form Muscle elastic zone in 2-year old yak (arrowheads) (VVG). F: Secondary internal elastic membrane ruptured, or even fall off, and smooth muscle membrane exposed in old yak (arrowheads) (VVG).</p

The ultra-structural changes of mitochondria in the yak heart with aging.

<p>A: Mitochondria aggregated around the nucleus in 1-day-old yak (arrowheads); B: Mitochondria ridge was uniform and well distributed (arrowheads) in 6-month-old yak. C: Giant mitochondria and the irregular ridge in 5-year-old yak (arrowheads). D, E, F: Collagen fibers in the 1-day-old, 6-month-old, and 2-year-old yak heart.</p