Capillary changes in skeletal muscle of patients with essential hypertension

Abstract

Arterial hypertension produces changes along the vascular tree. However, there are few reports on its effect on human muscle capillaries. This study demonstrates the effects of essential hypertension on the capillaries of human quadriceps muscle.Muscle biopsy was taken from quadriceps femoris in eight men with recent diagnosis of essential hypertension, without treatment. Biopsies were also taken from eight normotensive men and were used as controls. Fiber types were classified by ATPase reaction, capillaries counted in ␣-amylase-PAS stained sections and ultrastructure studied by conventional methods of transmission electron microscopy.No changes were found in capillaries or muscle fiber types by histochemical methods. However, electron microscopy revealed abnormal capillaries with endothelial cells infoldings into the lumen, as well as occluded or degenerated capillaries. In some cases the endothelial cell area covered by pericytes was increased. Basement membrane of capillaries was frequently increased in width, sometimes irregularly, and in other instances it was reduplicated. In transversely sectioned capillaries lumen diameter was reduced and wall thickness was increased, although total diameter was unchanged.In hypertensive patients the finding of some degenerated capillaries adjacent to muscle fibers could be interpreted as the beginning of a process of rarefaction. Some capillaries showed morphological changes, and the ratio wall thickness/lumen was increased. Anat Rec 256: 425-432, 1999. 1999 Wiley-Liss, Inc.

A Compartment Model of VEGF Distribution in Humans in the Presence of Soluble VEGF Receptor-1 Acting as a Ligand Trap

“…The luminal and abluminal diameters of individual capillaries were taken from measurements in the vastus lateralis as 4.86 and 6.39 µm respectively [89]. From these, the endothelium thickness was calculated to be 0.77 µm, while the lumen and endothelium CSA were calculated to be 18.6 and 13.5 µm 2 respectively, which agree with histological measurements from the mid-thigh (10.8±7.4 and 11.4±6.7 µm 2 ) [76].…”

Microcirculation and the Metabolic Syndrome

“…Spontaneously hypertensive rats have less 3rd‐ and 4th‐order arterioles and capillaries, a situation present before development of hypertension [ 222 , 388 ]. Another study showed normal total capillary diameter but reduced luminal diameter with the presence of protruded endothelial cells [ 157 ]. No change was found in subjects with low birth weight [ 404 ].…”

Capillary growth, ultrastructure remodelling and exercise training in skeletal muscle of essential hypertensive patients

“…Moreover, using electron microscopy, Hernandez and co‐workers showed thickening of the capillary wall and decreased capillary lumen diameter in individuals with mild essential hypertension (Hernández et al . ). Collectively, capillary rarefaction and, to some extent, basement membrane thickening, may limit diffusion conditions in the capillaries (Greene et al .…”

“…Specifically, hypertension has been shown to be associated with capillary rarefaction in various tissues (Conway , Hernández et al . , Debbabi et al . ) including skeletal muscle (Hansen et al .…”