Toll-like receptor 4 (TLR4) and cellular Src (c-Src) are closely associated with inflammatory cytokines and oxidative stress in hypertension, so we designed this study to explore the exact role of c-Src in the mechanism of action of the TLR4 signaling pathway in salt-induced hypertension. Salt-sensitive rats were given a high salt diet for 10 weeks to induce hypertension. This resulted in higher levels of TLR4, activated c-Src, pro-inflammatory cytokines, oxidative stress, and arterial pressure.
View Article and Find Full Text PDFBrain renin-angiotensin system (RAS) could regulate oxidative stress in the paraventricular nucleus (PVN) in the development of hypertension. This study was designed to explore the precise mechanisms of RAS acting on reactive oxygen species (ROS) in salt-induced hypertension. Male Wistar rats were administered with a high-salt diet (HS, 8.
View Article and Find Full Text PDFHigh-salt-induced inflammation and oxidative stress in the hypothalamic paraventricular nucleus (PVN) contribute to the pathogenesis of salt-sensitive hypertension. In this study, we hypothesized that chronic inhibition of nuclear factor-κB (NF-κB) activity in the PVN delays the progression of hypertension by upregulating anti-inflammatory cytokines, reducing NLRP3 (NOD-like receptor family pyrin domain containing 3) and IL-1β and attenuating p-IKKβ, NF-κB p65 activity and NAD(P)H oxidase in the PVN of salt-sensitive hypertensive rats. Dahl salt-sensitive rats received a high-salt diet (HS, 8 % NaCl) or a normal-salt diet (NS, 0.
View Article and Find Full Text PDFWe hypothesized that chronic inhibition of NF-κB activity in the hypothalamic paraventricular nucleus (PVN) delays the progression of hypertension and attenuates cardiac hypertrophy by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs), attenuating nuclear factor-κB (NF-κB) p65 and NAD(P)H oxidase in the PVN of young spontaneously hypertensive rats (SHR). Young normotensive Wistar-Kyoto (WKY) and SHR rats received bilateral PVN infusions with NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) or vehicle for 4 weeks. SHR rats had higher mean arterial pressure and cardiac hypertrophy as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, cardiomyocyte diameters of the left cardiac ventricle, and mRNA expressions of cardiac atrial natriuretic peptide (ANP) and beta-myosin heavy chain (β-MHC).
View Article and Find Full Text PDFWe hypothesized that chronic inhibition of tumor necrosis factor-alpha (TNF-α) in the hypothalamic paraventricular nucleus (PVN) delays the progression of hypertension and attenuates cardiac hypertrophy by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs), decreasing nuclear factor-κB (NF-κB) p65 and NAD(P)H oxidase activities, as well as restoring the neurotransmitters balance in the PVN of spontaneously hypertensive rats (SHR). Adult normotensive Wistar-Kyoto (WKY) and SHR rats received bilateral PVN infusion of a TNF-α blocker (pentoxifylline or etanercept) or vehicle for 4weeks. SHR rats showed higher mean arterial pressure and cardiac hypertrophy compared with WKY rats, as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, and cardiac atrial natriuretic peptide (ANP) and beta-myosin heavy chain (β-MHC) mRNA expressions.
View Article and Find Full Text PDFThe hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) play a critical role in the generation and maintenance of sympathetic nerve activity. The renin-angiotensin system (RAS) in the brain is involved in the pathogenesis of hypertension. This study was designed to determine whether inhibition of the angiotensin-converting enzyme (ACE) in the PVN modulates cytokines and attenuates oxidative stress (ROS) in the RVLM, and decreases the blood pressure and sympathetic activity in renovascular hypertensive rats.
View Article and Find Full Text PDFAngiotensin II (ANG II)-induced inflammatory and oxidative stress responses contribute to the pathogenesis of hypertension. In this study, we determined whether renin-angiotensin system (RAS) activation in the hypothalamic paraventricular nucleus (PVN) contributes to the ANG II-induced hypertensive response via interaction with neurotransmitters in the PVN. Rats underwent subcutaneous infusion of ANG II or saline for 4 weeks.
View Article and Find Full Text PDFZhejiang Da Xue Xue Bao Yi Xue Ban
September 2011
Objective: To investigate the effects of 100 Hz sinusoidal vibration on H reflex and M wave in rat soleus muscle following immobilization.
Methods: The immobilization of rat soleus muscle was induced as a disuse muscle model, and 100 Hz sinusoidal vibration was generated by a vibrator and applied to the immobilized soleus muscle, then the changes of H reflex and M wave in muscle were observed after 14 d.
Results: Compared to control, after 14 d of immobilization M(max) in soleus muscle decreased (P<0.
J Electromyogr Kinesiol
December 2011
V-wave, F wave and H-reflex responses of soleus were used to determine neural adaptations to 2-week immobilization and whether muscle vibration intervention during immobilization would attenuate the negative adaptations induced by immobilization. Thirty subjects were divided into the ankle immobilization group and the immobilization with muscle vibration group. Mechanical vibrations with constant low amplitude (0.
View Article and Find Full Text PDFSheng Li Xue Bao
June 2011
The aim of this study was to observe the electrophysiological characteristics of the isolated rat muscle spindle. The muscle spindle was isolated from rat soleus and the afferent discharge of the isolated muscle spindle was recorded by air-gap technique. In the basic physiological salt solution, the spontaneous impulses of muscle spindle were at a lower level with irregular intervals.
View Article and Find Full Text PDFThe present study aimed to study the changes of neurotrophin-3 (NT-3) expression of intrafusal muscle fibers in rat soleus muscles under simulated weightlessness. The tail-suspension (SUS) rat model was used to simulate weightlessness. Forty mature female Sprague-Dawley rats were randomly assigned to ambulatory control (CON), 3-day SUS, 7-day SUS, 14-day SUS and 21-day SUS groups.
View Article and Find Full Text PDFJ Muscle Res Cell Motil
September 2010
During hind limb unloading (HU), the soleus is often in a shortened position and the natural physiological stimulus of muscle spindles is altered, such that muscle spindle activity also changes. Using isolated spindle conditions, the present study investigates the electrophysiological activity and ultrastructure of muscle spindles following HU. Results show that muscle spindle discharges fall into either of two main patterns, single spikes or spike clusters in shortened positions, with a steady frequency of 18-38 spikes/s (mean 29.
View Article and Find Full Text PDFThe present study investigates changes in red nucleus (RN) neuronal activity and the role of glutamate receptors (GluRs) after simulated microgravity (tail-suspension) in the rat using single-unit recording and microinjection. The results showed that tail-suspension for 3, 7, and 14 days could induce a significant decrease in spontaneous firing rate of RN neurons in a time-dependent manner. Unilateral microinjection of glutamate into the RN significantly increased the firing rate of RN neurons, but the increased firing rate was significantly reduced following tail-suspension time.
View Article and Find Full Text PDFTo determine whether the neuronal activity of the spindle cord in muscle spindle afferent pathways is altered after a period of hindlimb unloading (Hu), and after recovery, we focused on c-Fos-immunoreactivity in the spinal cord evoked by excitation of the muscle spindle in normal gravity and after 3, 7, and 14 days of Hu, and after 14 days of Hu with an additional 2, 5, and 9 days of unrestricted cage activity. High frequency sinusoidal vibration (HFV) applied to the Achilles tendon was used for activation of the muscle spindle. Results showed that c-Fos-immunoreactive neurons evoked by HFV were mainly concentrated in lamina IV-VII of the ipsilateral spinal cord.
View Article and Find Full Text PDFObjective: To investigate the protective action of Epimedium against chemotherapy-induced damage to rat epididymides.
Methods: Fifty 60-day-old male rats were divided into a control, a model and a treatment group. Procarbazine was injected into the abdominal cavity of the model rats at the dose of 30 mg/(kg x d).
Objective: To study the effects of Ligustrazine (Lig) and Radix Astragali (Rad) on activities of myosin adenosine triphosphatase (mATPase) of soleus muscle and atrophy in tail-suspended rat.
Method: Weightlessness was simulated by tail suspension in female rats. The activities of mATPase of intrafusal and extrafusal fibres in soleus muscle were detected by method of Ca2(+)-ATPase.
Space Med Med Eng (Beijing)
August 2005
Objective: To study the effects of 100 Hz vibration on ultrastructure of intrafusal and extrafusal fibers in soleus muscle of tail-suspended rats.
Method: Weightlessness was simulated by tail suspension of female rats. The ultrastructure of intrafusal and extrafusal fibers of soleus muscle were examined after exposure to 100 Hz vibration.
Space Med Med Eng (Beijing)
October 2004
Objective: To study influence of 100 Hz sinusoidal vibration on muscle spindle afferents discharges of rat soleus muscles in simulated-weightlessness situation.
Method: The tail-suspended rat model was used to simulate weightlessness, and 100 Hz sinusoidal vibration was performed by a vibrator. Unit activity was recorded electrophysiologically from the centrally cut filaments of the spinal dorsal roots innervating muscle spindles of the rat soleus muscle; then observation on the changes in afferent discharges from muscle spindle in a rat soleus muscles were made after 7 d.
Objective: To study the effects of high frequency vibration on expression of myosin heavy chain (MHC) in intrafusal and extrafusal fibers in soleus muscles of tail-suspended rats.
Method: Weightlessness was simulated by tail suspension of female rats. Using immunohistochemistry technique, changes of expression of MHC in intrafusal and extrafusal fibers of soleus muscles were detected.