Changes in the gastric vascular network of malignant stroke-prone spontaneously hypertensive rats (M-SHRSP) after administration of the calcium antagonist manidipine.
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 casts of gastric capillaries were 5.9 +/- 0.6 microns in diameter with a regular smooth surface. In M-SHRSP, the overall vascular pattern was not regularly organized at 6.3 +/- 1.9 microns 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 microns. It seems that manidipine plays a role in the recovery of normal vascular structure, as well as decreasing blood pressure.
Department of Physiology, Kinki University School of Medicine, Osaka, Japan. kchiba@med.kindai.ac.jp
A
A
Chiba
Y
Y
Ohta
T
T
Suzuki
H
H
Nakanishi
S
S
Chichibu
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001158:Arteries / Q000187:drug effects / Q000648:ultrastructure; D001794:Blood Pressure / Q000187:drug effects*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002196:Capillaries / Q000187:drug effects* / Q000648:ultrastructure; D004095:Dihydropyridines / Q000494:pharmacology*; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008855:Microscopy, Electron, Scanning; D009578:Nitrobenzenes; D010879:Piperazines; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013270:Stomach / Q000098:blood supply / Q000187:drug effects* / Q000648:ultrastructure
D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D009578:Nitrobenzenes; D010879:Piperazines; C054218:manidipine