Changes in the gastric vascular network of malignant stroke-prone spontaneously hypertensive rats (M-SHRSP) after administration of the calcium antagonist manidipine
Chiba, A.; Ohta, Y.; Suzuki, T.; Nakanishi, H.; Chichibu, S.
Research Communications in Molecular Pathology and Pharmacology 100(2): 151-160
1998
ISSN/ISBN: 1078-0297 PMID: 9667069 Document Number: 487316
In malignant SHRSP (M-SHRSP), a strain of stroke-prone spontaneously hypertensive rat (SHRSP), blood pressure rapidly increases during early development (5 weeks of age). Changes in the gastric vascular architecture of WKY and M-SHRSP were investigated using scanning electron microscope images of vascular casts focusing on the morphological differences in the three-dimensional arrangement of the capillaries. In WKY, the density, tortuosity and regular honeycomb formation of the gastric vessels were studied. The cases of gastric capillaries were 5.9 +- 0.6 mum in diameter with a regular smooth surface. In M-SHRSP, the overall vascular pattern was not regularly organized at 6.3 +- 1.9 mum in capillary diameter. Administration of the Ca antagonist, manidipine, to 11-week-old M-SHRSP with hypertensive vascular lesions decreased blood pressure and prolonged the rats' survival. With the administration of manidipine, vascular morphological patterns became similar to that of normotensive WKY, and the mean capillary diameter was 8.4 +- 1.2 mum. It seems that manidipine plays a role in the recovery of normal vascular structure, as well as decreasing blood pressure.