Could hypertension possibly be adaptive?^‡

Abstract

1. We believe that the ultimate goal of cardiovascular regulatory mechanisms is not the regulation of arterial blood pressure (BP), but the maintenance of tissue blood flows commensurate with metabolic requirements. Thus, elevated BP can potentially contribute to optimizing tissue blood flows under select circumstances; for example, when there are primary defects in autoregulation of tissue blood flows. 2. The hypothesis that a primary defect in autoregulation of tissue blood flows may be responsible for the development of hypertension is presented. It is argued that, in this context, at least part of the rise in BP may be reflexly driven by a 'metaboreflex', a homeostatic mechanism acting to regulate tissue blood flows. 3. We argue that in the context of primary defects in autoregulation of tissue blood flows, the ability to generate and sustain a hypertensive phenotype increases the lifespan of species (i.e. if it were not for this adaptive hypertensive phenotype, death due to circulatory failure would occur much earlier). 4. Experimental and clinical evidence that indirectly supports the hypothesis is reviewed briefly and a means for testing this hypothesis is suggested.

Redefining ADHD Using an Adult Population: Should Inattention be Viewed as a Separate Dimension From Cognitive and Physiological Activity Level?

“…Yet despite the risks involved both in increasing and decreasing blood pressure, the body will do so to maintain blood-flow and subsequent oxygenation of tissues (Cowley, 1980). However, it has also been proposed that such autoregulation of blood pressure may result in chronic hypertension, not as a primary disorder, but in response to other chronic circulatory issues (Prakash & Fink, 2010). In the case of BP, and as is being proposed with activity level, the variability is an adaptation to a changing environment, even if the adaptation carries its own risks.…”

Blood pressure long term regulation: A neural network model of the set point development

“…In this way, the average long-term level of BP is an emergent property of a decentralized control system. Besides, these authors contend that the ability to generate a hypertensive phenotype increases the species lifespan [45,46]. …”

Pathophysiologic Aspects of Hypertension

“…Efferent Nerves: The autonomic nervous system includes sympathetic and parasympathetic divisions and the associated afferent (sensory) feedback nerves that affect each division. Sympathetic and parasympathetic motor neuron cell bodies are found in peripheral ganglia [18][19][20][21].…”

“…This causes an increase in sodium (Na + ) hydrogen (H + ) exchanger activity at the apical membrane, allowing sodium to enter the cell, whereupon it is pumped out of the cell through Na + /K + adenosine triphosphatase (ATPase) located in basolateral membranes. Water of hydration follows Na + ions through (transcellular route) and between (paracellular route) these high permeability epithelial cells [20,21].…”