Vascular reactivity to calcitonin gene-related peptide is enhanced in subtotal nephrectomy-salt induced hypertension
| Autor: | Travis W. Hein, Scott C. Supowit, Prakash C. Gupta, Ian M. Dickerson, Khurshed A. Katki, Donald J. DiPette, Lih Kuo |
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| Rok vydání: | 2011 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Physiology Calcitonin Gene-Related Peptide Vasodilator Agents Vascular Biology and Microcirculation medicine.medical_treatment Blotting Western Blood Pressure Subtotal nephrectomy Peptide Vasodilation Calcitonin gene-related peptide Nephrectomy Rats Sprague-Dawley Adrenomedullin Physiology (medical) Internal medicine medicine Animals Mesentery Sodium Chloride Dietary Infusions Intravenous Antihypertensive Agents chemistry.chemical_classification Analysis of Variance Dose-Response Relationship Drug business.industry Rats Arterioles Disease Models Animal Endocrinology Blood pressure chemistry Calcitonin Hypertension Cardiology and Cardiovascular Medicine business Receptors Calcitonin Gene-Related Peptide |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 301:H683-H688 |
| ISSN: | 1522-1539 0363-6135 |
| Popis: | In subtotal nephrectomy (SN)- and salt-induced hypertension, calcitonin gene-related peptide (CGRP) plays a compensatory role to attenuate the blood pressure increase in the absence of an increase in the neuronal synthesis and release of this peptide. Therefore, the purpose of this study was to determine whether the mechanism of this antihypertensive activity is through enhanced sensitivity of the vasculature to the dilator actions of this neuropeptide. Hypertension was induced in Sprague-Dawley rats by SN and 1% saline drinking water. Control rats were sham-operated and given tap water to drink. After 11 days, rats had intravenous (drug administration) and arterial (continuous mean arterial pressure recording) catheters surgically placed and were studied in a conscious unrestrained state. Baseline mean arterial pressure was higher in the SN-salt rats (157 ± 5 mmHg) compared with controls (128 ± 3 mmHg). Administration of CGRP (and adrenomedullin) produced a significantly greater dose-dependent decrease in mean arterial pressure in SN-salt rats compared with controls (∼2.0-fold for both the low and high doses). Interestingly, isolated superior mesenteric arterioles from SN-salt rats were significantly more responsive to the dilator effects of CGRP (but not adenomedullin) than the controls (pEC50, SN-salt, 14.0 ± 0.1 vs. control, 12.0 ± 0.1). Analysis of the CGRP receptor proteins showed that only the receptor component protein was increased significantly in arterioles from SN-salt rats. These data indicate that the compensatory antihypertensive effects of CGRP result from an increased sensitivity of the vasculature to dilator activity of this peptide. The mechanism may be via the upregulation of receptor component protein, thereby providing a more efficient coupling of the receptor to the signal transduction pathways. |
| Databáze: | OpenAIRE |
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