Stress and High Blood Pressure: What is the connection?
You have seen persons having high blood pressure in your circle. Sometimes high blood pressure can affect comparatively younger age group also. Have you ever enquired about what caused them this menace?
Scientists have discovered the fact that stress can be a predisposing factor for high blood pressure to occur. It also aggravates the situation among the existing hypertensive persons (people living with high blood pressure).
Stress triggers the release of some hormones in our body. These are Adrenaline, Cortisol, and Dopamine. All of these hormones have a direct role-playing action in increasing blood pressure.
Adrenaline has a positive action over the α-receptors present in various parts of our body.
The mediation of α action is varied. It goes like this-
In smooth muscles of our body including the vascular muscle there are abundance of α-receptors. The muscles are contracted by the action of the α1 receptors. The activated G protein increases IP3/DAG production. Then there is mobilization of Ca2+ from intracellular organelle, mainly from the mitochondrion. Ca2+ activates the Calmodulin dependent myosin light chain kinase (an enzyme- present in the muscle tissue). This enzyme helps in the phosphorylation of myosin. It causes contraction of the Actin-Myosin complex. Thus, the whole muscle fiber is contracted. The vasoconstrictor α2 receptors probably enhance Ca2+ influx without utilizing IP3.
The prejunctional α2 receptors appear to inhibit neuronal Ca2+ channels and limit the intracellular availability of Ca2 + by decreasing cAMP production. The neurotransmitter (Noradrenaline) release is consequently diminished. Hyperpolarization through activation of K+ channels may also occur.
Glucocorticoids restrict capillary permeability; maintain the tones of arterioles and myocardial contractility. They have a permissive or pressor action of Adrenaline and Angiotensin. They also play a permissive role in development of high blood pressure. The principal mineralocorticoid action is enhancement of Sodium reabsorption in the distal convoluted tubule in the kidney. There is associated increase in K+ and H+ excretion. If there is increased production of mineralocorticoids as in case of stress, there is increase in the maximal tubular reabsorptive capacity for Na+; there is retention of Sodium from the kidney. This sodium in turn brings water from the kidney (reabsorption). The total volume of the blood is increased and it helps in the increase of blood pressure.
The peripherally formed dopamine (DA) can cause rise in the heart rate acting on β adrenergic receptors. Though DA can stimulate vascular adrenergic receptor as well, prominent rise in the blood pressure is not seen.
Younger persons will face this menace more because they have more active gland that can secrete hormones in a larger scale.
Therefore, it is evident that stress has a direct triggering effect on the body, which in turn gives rise to increase in the blood pressure. If stress can be taken away, all the hormonal level will come back to normal and then in turn blood pressure will be normal also.
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