Effect of high thoracic epidural block on expression of β1-ARK mRNA in lymphocytes in elderly patients with essential hypertension complicated with left ventricular hypertrophy

Abstract

Objective To investigate the effect of high thoracic epidural block (HTEB) on the expression of β-adrenergie receptor kinaseo-1 (β1-ARK) mRNA in the lymphocytes in the elderly patients with essential hypertension complicated with left ventricular hypertrophy (LVH). Methods Twenty ASA Ⅱ or Ⅲ elderly patients with essential hypertension complicated with LVH scheduled for subtotal gastrectomy under general anesthesia were randomly divided into 2 groups (n = 10 each) : intravenous-inhalational anesthesia group (group Ⅰ) and HTEB combined with intravenous-inhalational anesthesia group (group Ⅱ). In group Ⅱ , epidural anesthesia was performed at T6.7 and ropivacaine was infused until 72 h after operation for HTEB. In group Ⅰ ,patient-controlled intravenous analgesia (PCIA) was performed with fentanyl in 72 h after operation. The heart rate variability (HRV) parameters, including total power (TP), high frequency (HF) power and low frequency (LF) power, were recorded 30 min after entering the operating room (baseline), at the recovery time of consciousness (T1), and on 1st, 3rd and 5th day after operation (T2-4) ,and LF/HF was calculated. VAS scores were recorded and the severity of pain was assessed. The blood samples were drawn from the right internal jugular vein at the time points mentioned above for determination of β1-ARK mRNA and β1-arrestin mRNA expression. Resets There were no significant differences in VAS scores at each time point between two groups (P > 0.05). TP, HF, LF and LF/HF were significantly increased, and β1-ARK mRNA expression was down-regulated after operation in group Ⅱcompared with group Ⅰ (P 0.05) . TP was siguificantly increased, HF significantly decreased, and β1-ARK mRNA expression up-regulated in two groups at T2 compared with those at T1 (P 0.05). TP was inversely correlated with the expression of β1-ARK mRNA in the lymphocytes during the perioperative period using Pearson correlation analysis (r=-0.520, P <0.01). Conclusion HTEB can maintain the balance of the autonomic nervous system and improve HRV during upper abdominal surgery in the elderly patients with essential hypertension complicated with LVH, and the mechanism is related to the up-regulation of β1-ARK mRNA expression. Key words: Anesthesia, epidural; β-adrenergic receptor kinases; RNA, messenger; Hypertension; Hypertrophy, left ventricular; Aged