Author:
Vari Sydney,Guild Sarah-Jane,George Bindu,Ramchandra Rohit
Abstract
AbstractWe have previously shown that elevations in intracranial pressure (ICP) within physiological ranges in normotensive animals increase arterial pressure; termed the intracranial baroreflex. Hypertension is associated with alterations in reflexes which maintain arterial pressure however, whether the intracranial baroreflex is altered is not known. Hence, in the present study, we tested the hypothesis that in hypertension, physiological increases in ICP would not be accompanied with an increase in arterial pressure. Renovascular hypertension was associated with no change in heart rate, renal blood flow or ICP levels compared to the normotensive group. ICV infusion of saline produced a ramped increase in ICP of 20 ± 1 mmHg. This was accompanied by an increase in arterial pressure (16 ± 2 mmHg) and a significant decrease in renal vascular conductance. ICV infusion of saline in the hypertensive group also increased ICP (19 ± 2 mmHg). However, the increase in arterial pressure was significantly attenuated in the hypertensive group (5 ± 2 mmHg). Ganglionic blockade abolished the increase in arterial pressure in both groups to increased ICP. Our data indicates that physiological increases in ICP lead to increases in arterial pressure in normotensive animals but this is severely attenuated in renovascular hypertension.
Funder
Health Research Council of New Zealand
National Heart Foundation of New Zealand
Publisher
Springer Science and Business Media LLC
Reference38 articles.
1. Cushing, H. Concerning a definitive regulatory mechanism of the vaso-motor centre which controls blood pressure during cerebral compression. Bull. Johns Hopk Hosp. 12, 290–292 (1901).
2. Paton, J. F., Dickinson, C. J. & Mitchell, G. Harvey Cushing and the regulation of blood pressure in giraffe, rat and man: introducing “Cushing’s mechanism”. Exp. Physiol. 94, 11–17 (2009).
3. Guild, S. J., Saxena, U. A., McBryde, F. D., Malpas, S. C. & Ramchandra, R. Intracranial pressure influences the level of sympathetic tone. Am. J. Physiol. Regul. Integr. Comp Physiol. 315, R1049–R1053 (2018).
4. Marina, N. et al. Astrocytes monitor cerebral perfusion and control systemic circulation to maintain brain blood flow. Nat. Commun. 11, 131 (2020).
5. Schmidt, E. A. et al. Intracranial pressure is a determinant of sympathetic activity. Front. Physiol. 9, 11 (2018).
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