Combined effect of neonatal sympathectomy and adrenal demedullation on blood pressure and vascular changes in spontaneously hypertensive rats
| Autor: | J. Tsoporis, F. H. H. Leenen, Robert M.K.W. Lee, Michael D. Coughlin, K. R. Borkowski |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
medicine.medical_specialty
Physiology medicine.medical_treatment Hemodynamics Blood Pressure Rats Inbred WKY Catecholamines Heart Rate medicine.artery Internal medicine Rats Inbred SHR medicine Animals cardiovascular diseases Superior mesenteric artery Sympathectomy Mesenteric arteries Guanethidine business.industry musculoskeletal system Mesenteric Arteries Rats medicine.anatomical_structure Blood pressure Endocrinology Adrenal Medulla Hypertension cardiovascular system Catecholamine Cardiology and Cardiovascular Medicine business Adrenal medulla circulatory and respiratory physiology medicine.drug |
| Zdroj: | Circulation research. 69(3) |
| ISSN: | 0009-7330 |
| Popis: | Neonatal sympathectomy using a combined treatment with antiserum to nerve growth factor and guanethidine during the first 4 weeks after birth was carried out in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. Bilateral adrenal demedullation was performed in 4-week-old sympathectomized SHR and WKY rats. The development of hypertension in SHR was prevented by sympathectomy, but the blood pressure (BP) was still higher than in age-matched WKY rats. Demedullation reduced the BP of sympathectomized SHR to the same level as that of WKY rats. Heart rates of SHR and WKY rats were not affected by the treatments. Morphometric measurements of the mesenteric arteries showed that sympathectomy significantly reduced the medial mass in the mesenteric arteries of SHR, mainly through a reduction in the number of smooth muscle cell layers. In sympathectomized SHR, demedullation increased the lumen size of muscular arteries under maximally relaxed conditions, which might explain the further reduction in BP in these animals. Demedullation in sympathectomized SHR and WKY rats caused a decrease in smooth muscle cell layers in the superior mesenteric artery, but the same treatment resulted in a slight increase in the number of smooth muscle cell layers in the large and small mesenteric arteries of SHR and WKY rats. Adventitial area was increased in some mesenteric arteries of SHR and WKY rats by sympathectomy, and demedullation caused a further increase in the size of adventitia in WKY rats. Heart weight in SHR was normalized to the level found in WKY rats by sympathectomy and demedullation. We conclude that in sympathectomized SHR, the elevated BP was maintained by the adrenal medulla. |
| Databáze: | OpenAIRE |
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