Baroreflex dysfunction in diabetes mellitus. II. Site of baroreflex impairment in diabetic rabbits
| Autor: | Francois M. Abboud, G. Hajduczok, Mark W. Chapleau, T. S. McDowell |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Bradycardia
medicine.medical_specialty Baroreceptor Sympathetic Nervous System Physiology Baroreflex Kidney Diabetes Mellitus Experimental chemistry.chemical_compound Heart Rate Physiology (medical) Internal medicine Diabetes mellitus Alloxan Heart rate Medicine Animals Phenylephrine business.industry Vagus Nerve medicine.disease Electric Stimulation Endocrinology Blood pressure chemistry Rabbits medicine.symptom Cardiology and Cardiovascular Medicine business medicine.drug |
| Zdroj: | The American journal of physiology. 266(1 Pt 2) |
| ISSN: | 0002-9513 |
| Popis: | In our companion paper [T. S. McDowell, M. W. Chapleau, G. Hajduczok, and F. M. Abboud, Am. J. Physiol. 266 (Heart Circ. Physiol. 35): H235-H243, 1994] we report that baroreflex-mediated bradycardia is impaired in diabetic rabbits. The purpose of the present study was to identify the site of impairment. Diabetes was induced in rabbits by alloxan (90–100 mg/kg iv; n = 7). Alloxan-treated rabbits that remained normoglycemic (n = 8) and rabbits given saline instead of alloxan (n = 4) served as controls. Twenty-four weeks after administration of alloxan or saline, rabbits were anesthetized with alpha-chloralose. Aortic baroreceptor and renal sympathetic nerve activity (RSNA) were recorded during phenylephrine- and nitroglycerin-induced changes in arterial pressure. The slope of the baroreceptor pressure-activity relation was not significantly different in diabetic rabbits (1.3 +/- 0.3%/mmHg, n = 7) compared with either alloxan-treated (1.3 +/- 0.1%/mmHg) or saline-treated normoglycemic rabbits (1.2 +/- 0.2%/mmHg). The slope of the arterial pressure-RSNA relation was not significantly different in diabetic rabbits (-3.5 +/- 0.3%/mmHg, n = 7) compared with the alloxan-treated normoglycemic rabbits (-3.0 +/- 0.4%/mmHg, n = 8) and was greater than that in saline-treated normoglycemic rabbits (-1.9 +/- 0.3%/mmHg, n = 4; P < 0.05). The decreases in heart rate in response to electrical stimulation (10 V, 2 ms, 0.5–16 Hz) of the cut peripheral end of the right cervical vagus were similar in diabetic and alloxan-treated normoglycemic rabbits.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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