Increased Vascular Alpha-1 Adrenergic Receptor Sensitivity in Older Adults with Post-traumatic Stress Disorder.

Increased Vascular Alpha-1 Adrenergic Receptor Sensitivity in Older Adults with Post-traumatic Stress Disorder. Am J Physiol Regul Integr Comp Physiol. 2020 Sep 23;: Authors: Hartwig CL, Sprick JD, Jeong J, Hu Y, Morison DG, Stein CM, Paranjape SY, Park J Abstract Post-traumatic stress disorder (PTSD) is an independent risk factor for the development of hypertension and cardiovascular disease. Patients with PTSD have heightened blood pressure and sympathetic nervous system reactivity; however, it is unclear if PTSD patients have exaggerated vasoconstriction in response to sympathetic nerve activation that could also contribute to increased blood pressure reactivity. Therefore, we hypothesized that patients with PTSD have increased sensitivity of vascular α1 adrenergic receptors (α1AR), the major mediators of vasoconstriction in response to release of norepinephrine at sympathetic nerve terminals. To assess vascular α1AR sensitivity, we measured the degree of venoconstriction in a dorsal hand vein in response to exponentially increasing doses of the selective α1AR agonist phenylephrine (PE) in 9 patients with PTSD (age=59±2 years) and 10 age-matched controls (60±1 years). Individual dose-response curves were generated to determine the dose of PE that induces 50% of maximal venoconstriction (i.e. PE ED50) reflective of vascular α1AR sensitivity. In support of our hypothesis, PE ED50 values were lower in PTSD compared to controls...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research