Structural wall tissue alterations of the microvasculature in the course of spontaneous hypertension of rats.
The existence of structural reactions of the microvasculature of spontaneously hypertensive rats (SHR) and the underlying causal mechanisms are generally controversially discussed. Ninety-two male SHR aged 3-52 weeks and 118 normotensive age and sex matched controls were investigated. A new histomorphometric procedure was applied that ascertains structural changes in microvessels with diameters below 9 microns, between 9 microns and 19 microns and above 19 microns in anatomically defined sections of the skeletal muscle, heart and pancreas. Significant rises in the numerical and area densities of microvessel surfaces document a pathological increase in wall tissue of the microvasculature in all 3 organs and stages of spontaneous hypertension, with the exception of the coronary microvessels of 8-16 week old SHR where this progressive structural reaction was antagonized. How far the hypertrophy of the microvascular wall tissue is connected with an increase in wall thickness disproportional to the corresponding lumen wideness remained unknown. A positive correlation between the increase in blood pressure and wall tissue was only substantiated in the pancreas microvasculature. The generalized preferential occurrence of pathological reactions in vessels with diameters below 19 microns in the early established phase indicates that the microvascular control changes in this phase of spontaneous hypertension (SH).
Herrmann
H J
HJ
Institute of Heart and Circulation Research, Berlin, Germany.
Moritz
V
V
Kühne
C
C
D000818:Animals; D003331:Coronary Vessels / Q000473:pathology; D006973:Hypertension / Q000473:pathology*; D007091:Image Processing, Computer-Assisted; D008297:Male; D008833:Microcirculation / Q000473:pathology; D009131:Muscle, Smooth, Vascular / Q000473:pathology*; D009132:Muscles / Q000098:blood supply*; D010179:Pancreas / Q000098:blood supply*; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY