ABSTRACT
<p><b>PURPOSE</b>Renal denervation (RD) has been demonstrated to be an effective approach to reduce blood pressure for those with resistant hypertension. Yet, we aimed to explore the effect and possible mechanism of RD on blood-pressure response to hemorrhagic shock in spontaneously hypertensive rats.</p><p><b>METHODS</b>A total of 48 male spontaneously hypertensive rats were randomized to three groups: study group, sham-operation group and control group. RD was achieved by cutting off renal nerves and swabbing phenol on it. Ten weeks after RD, 8 rats in each group were sacrificed to collect the kidney and heart tissues. The remaining rats were subjected to an operation to induce hemorrhagic shock which would lead to 40% loss of total blood volume, and observed for 120 min. The serum concentration of norepinephrine was measured before and three weeks after RD.</p><p><b>RESULTS</b>The blood-pressure and norepinephrine levels were reduced significantly after RD (p < 0.05). Systolic blood pressure and diastolic blood pressure of the surgery group were higher than those in the sham and control groups at 15, 30 and 45 min after hemorrhagic shock (p < 0.05), while no significant difference was observed at 60, 90 and 120 min (p > 0.05). Additionally, the beta-1 adrenergic receptor (β1-AR) in the study group was significantly higher than those in the other two groups (p < 0.05) after hemorrhagic shock.</p><p><b>CONCLUSION</b>This study demonstrated that RD could to some extent improve blood-pressure response to hemorrhagic shock in an established model of severe hemorrhagic shock in spontaneously hypertensive rats. The mechanism might be associated with up-regulation of β1-AR.</p>
ABSTRACT
BACKGROUND: The hemodynamic responses to endotracheal intubation are associated with sympathoadrenal activity. Polymorphisms in the beta1-adrenergic receptor (beta1AR) gene can alter the pathophysiology of specific diseases. The aim of this study is to investigate whether the Ser49Gly and Arg389Gly polymorphism of the beta1AR gene have different cardiovascular responses during endotracheal intubation under sevoflurane anesthesia. METHODS: Ninety-one healthy patients undergoing general anesthesia were enrolled. Patients underwent slow inhalation induction of anesthesia using sevoflurane in 100% oxygen. Vecuronium 0.15 mg/kg was given for muscle relaxation. Endotracheal intubation was performed by an anesthesiologist. The mean arterial pressure (MAP), heart rate (HR), and the corrected QT (QTc) interval were measured before induction, before laryngoscopy, and immediately after tracheal intubation. Genomic DNA was isolated from the patients' peripheral blood and then evaluated for the beta1AR-49 and beta1AR-389 genes using an allele-specific polymerase chain reaction method. RESULTS: No differences were found in the baseline values of MAP, HR, and the QTc interval among beta1AR-49 and beta1AR-389, respectively. In the case of beta1AR-49, the QTc interval change immediately after tracheal intubation was significantly greater in Ser/Ser genotypes than in Ser/Gly genotypes. No differences were observed immediately after tracheal intubation in MAP and HR for beta1AR-49 and beta1AR-389. CONCLUSIONS: We found an association between the Ser49 homozygote gene of beta1AR-49 polymorphism and increased QTc prolongation during endotracheal intubation with sevoflurane anesthesia. Thus, beta1AR-49 polymorphism may be useful in predicting the risk of arrhythmia during endotracheal intubation in patients with long QT syndrome.
Subject(s)
Humans , Anesthesia , Anesthesia, General , Arrhythmias, Cardiac , Arterial Pressure , DNA , Genotype , Heart Rate , Hemodynamics , Homozygote , Inhalation , Intubation , Intubation, Intratracheal , Laryngoscopy , Long QT Syndrome , Methyl Ethers , Muscle Relaxation , Oxygen , Polymerase Chain Reaction , Vecuronium BromideABSTRACT
Na +/H + exchanger 1 (NHE1) is a major contributor to ischemic and reperfusion injury. It is emerging that NHE 1 also contributes to myocardial hypertrophy and heart failure due to chronic maladaptive stimulation. It appears that NHE 1 may represent a common downstream mediator for various hypertrophic factor, such as angiotensinⅡ,beta (1) and alpha (1) adrenergic receptor activation. NHE 1 inhibition may be a effective new therapeutic approach for prevention and treatment of heart failure.-