Blood pressure control in arterial- and cardiopulmonary receptor denervated dogs.
The mechanisms influencing arterial blood pressure and heart rate were studied in conscious foxhounds after chronic sino-aortic and cardiopulmonary denervation (N = 6). In previous investigations it was shown, that this denervation produces hypertension and tachycardia, which is confirmed by the present study: Mean arterial blood pressure increased from 101 +/- 3 to 123 +/- 6 mmHg (P less than 0.05), and heart rate rose from 85 +/- 6 to 124 +/- 5 beats min-1 (P less than 0.001). The variability of mean arterial blood pressure, but not that of heart rate increased (from 6 +/- 1 to 22 +/- 2 mmHg (P less than 0.001). The administration of the alpha-adrenergic blocker prazosin reduced both mean arterial blood pressure (-33 +/- 8 mmHg, P less than 0.01) and its variability (-12 +/- 1 mmHg, P less than 0.01), thus suggesting an alpha-adrenergic mediated hypertension. beta-blockade by propranolol blunted the heart rate increase (-24 +/- 5 beats min-1, P less than 0.05). Although plasma renin activity increased in the denervated dogs, converting enzyme inhibition had little effect on mean arterial blood pressure and heart rate. In conclusion, chronic sino-aortic and cardiopulmonary denervation enhances the alpha and beta-adrenergic component of cardiovascular control in a different fashion. While the alpha-adrenergic component induces fluctuations around an elevated arterial blood pressure level, the beta-adrenergic tone to the heart increases without any significant increase in variability.
Persson
P B
PB
I. Physiologisches Institute, Ruprecht-Karls Universität Heidelberg, F.R.G.
Ehmke
H
H
Kirchheim
H R
HR
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000502:physiology / Q000648:ultrastructure; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D003714:Denervation; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology; D008168:Lung / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D011224:Prazosin / Q000494:pharmacology; D011311:Pressoreceptors / Q000502:physiology*; D011433:Propranolol / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000502:physiology; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D012083:Renin / Q000378:metabolism; D013610:Tachycardia / Q000209:etiology / Q000503:physiopathology
D000806:Angiotensin-Converting Enzyme Inhibitors; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D012083:Renin; D011224:Prazosin