Increased vascular α1-adrenergic receptor sensitivity in older adults with posttraumatic stress disorder

• DOI: 10.1152/ajpregu.00155.2020
• Publication Date: 2020-09-23T19:19:18Z
• Authors: Cortnie L. Hartwig; Justin D. Sprick; Jinhee Jeong; Yingtian Hu; Doree G. Morison; C. Michael Stein; Sachin Paranjape; Jeanie Park
• Keywords: Phenylephrine; Sympathetic nervous system

Posttraumatic stress disorder (PTSD) is an independent risk factor for the development of hypertension and cardiovascular disease. Patients with PTSD have heightened blood pressure sympathetic nervous system reactivity; however, it unclear if patients exaggerated vasoconstriction in response to nerve activation that could also contribute increased reactivity. Therefore, we hypothesized sensitivity vascular α1-adrenergic receptors (α1ARs), major mediators release norepinephrine at terminals. To assess α1AR sensitivity, measured degree venoconstriction a dorsal hand vein exponentially increasing doses selective agonist, phenylephrine (PE), 9 (age = 59 ± 2 yr) 10 age-matched controls 60 1 yr). Individual dose-response curves were generated determine dose PE induces 50% maximal (i.e., ED50) reflective sensitivity. In support our hypothesis, ED50 values lower compared (245 54 ng/min vs. 1,995 459 ng/min, P 0.012), indicating PTSD. The group had increase slope rise venoconstriction, indicative altered venoconstrictive reactivity (19.8% 1.2% 15.1% 1.2%, 0.009). Heightened may augmented sympathoexcitation disease this patient population.