BACKGROUND: Microneurographic assessment of processed bursts that represent multi-unit nerve discharge has suggested that sympathetic hyperactivity occurs in pregnancy induced hypertension and pre-eclampsia in comparison with normal pregnancy. OBJECTIVE: To examine the differences between peripheral sympathetic outputs in pregnancy-induced hypertension and normal pregnancy by directly measuring single impulses of neural discharge. DESIGN: We compared the sympathetic neural discharge at rest and its reflex responses in subjects with pregnancy-induced hypertension and normal pregnancy and re-examined their progress at least 6 weeks post partum. The patients with pregnancy-induced hypertension were hospital in-patients for whom the diagnosis could be strictly defined and the normally pregnant women were recruited to match the former. METHODS: Standard microneurography was performed to quantify single impulses of action potentials, together with the processed multi-unit bursts from fibres innervating the leg muscles. We measured neural discharge with vascular vasoconstrictive properties, heart rate and finger arterial blood pressure at rest and their responses to standard isometric hand-grip exercise and cold pressor tests. RESULTS: As expected, patients with pregnancy-induced hypertension (n = 13) had higher levels of finger arterial blood pressure than did women with normal pregnancies (n = 11). The number of single impulses of action potentials (per min and per 100 cardiac beats) in resting patients with pregnancy-induced hypertension was more than three times greater than that in resting women with normal pregnancies, and the number of multi-unit bursts was twofold greater. After delivery of their child, sympathetic activity and heart rate in nine patients decreased, but finger arterial blood pressure decreased in patients with pregnancy-induced hypertension only. CONCLUSIONS: From results of cross-sectional and longitudinal studies, pregnancy-induced hypertension is associated with a greater resting sympathetic output than that of women with normal pregnancies. Follow-up data after parturition suggest that this hyperactivity is not the only cause of hypertension.
BACKGROUND: Microneurographic assessment of processed bursts that represent multi-unit nerve discharge has suggested that sympathetic hyperactivity occurs in pregnancy induced hypertension and pre-eclampsia in comparison with normal pregnancy. OBJECTIVE: To examine the differences between peripheral sympathetic outputs in pregnancy-induced hypertension and normal pregnancy by directly measuring single impulses of neural discharge. DESIGN: We compared the sympathetic neural discharge at rest and its reflex responses in subjects with pregnancy-induced hypertension and normal pregnancy and re-examined their progress at least 6 weeks post partum. The patients with pregnancy-induced hypertension were hospital in-patients for whom the diagnosis could be strictly defined and the normally pregnant women were recruited to match the former. METHODS: Standard microneurography was performed to quantify single impulses of action potentials, together with the processed multi-unit bursts from fibres innervating the leg muscles. We measured neural discharge with vascular vasoconstrictive properties, heart rate and finger arterial blood pressure at rest and their responses to standard isometric hand-grip exercise and cold pressor tests. RESULTS: As expected, patients with pregnancy-induced hypertension (n = 13) had higher levels of finger arterial blood pressure than did women with normal pregnancies (n = 11). The number of single impulses of action potentials (per min and per 100 cardiac beats) in resting patients with pregnancy-induced hypertension was more than three times greater than that in resting women with normal pregnancies, and the number of multi-unit bursts was twofold greater. After delivery of their child, sympathetic activity and heart rate in nine patients decreased, but finger arterial blood pressure decreased in patients with pregnancy-induced hypertension only. CONCLUSIONS: From results of cross-sectional and longitudinal studies, pregnancy-induced hypertension is associated with a greater resting sympathetic output than that of women with normal pregnancies. Follow-up data after parturition suggest that this hyperactivity is not the only cause of hypertension.
Authors: Yoshiyuki Okada; Stuart A Best; Sara S Jarvis; Shigeki Shibata; Rosemary S Parker; Brian M Casey; Benjamin D Levine; Qi Fu Journal: J Physiol Date: 2015-01-26 Impact factor: 5.182
Authors: Mark B Badrov; Sun Young Park; Jeung-Ki Yoo; Michinari Hieda; Yoshiyuki Okada; Sara S Jarvis; Abigail S Stickford; Stuart A Best; David B Nelson; Qi Fu Journal: Hypertension Date: 2019-02 Impact factor: 10.190
Authors: Zhigang Shi; Kim M Hansen; Kristin M Bullock; Yoichi Morofuji; William A Banks; Virginia L Brooks Journal: J Physiol Date: 2019-07-11 Impact factor: 5.182