OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Neiguan" (PC 6) on myocardial fibrosis in spontaneously hypertensive rats (SHR), and explore preliminarily the mediating role of cholinergic anti-inflammatory pathway (CAP) and its downstream nuclear factor κB (NF-κB) signaling pathway. METHODS: Six 12-week-old WKY male rats were employed as the normal group. Eighteen 12-week-old SHR were randomly divided into 3 groups, i.e. a model group, an EA group and a blocking group (EA after blocking α7 nicotinic acetylcholine receptor [α7nAchR]), with 6 rats in each one. In the EA group, EA was delivered at "Neiguan"(PC 6) and the site 0.5 cm from its left side, with disperse-dense wave, 2 Hz/15 Hz in frequency and 1 mA in current intensity. One intervention took 30 min and was given once every 2 days, lasting 8 weeks. In the blocking group, prior to each EA, the α7nAchR specific blocker, α-bungartoxin was injected intravenously in the tails of the rats. After EA intervention, the systolic blood pressure (SBP), the diastolic blood pressure (DBP) and the mean arterial pressure (MAP) were measured with non-invasive blood pressure monitor. Using echocardiogram, the left ventricular (LV) anterior wall end-diastolic thickness (LVAWd) , LV posterior wall end-diastolic thickness (LVPWd) and the LV end-diastolic internal diameter (LVIDd) were measured. The level of hydroxyproline (Hyp) in the myocardial tissue was determined by using alkaline hydrolysis, and that of acetylcholine (Ach) was detected by ELISA. With the real-time PCR adopted, the mRNA expression of NF-κB p65, tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-6 were determined. RESULTS: Compared with the normal group, SBP, DBP, MAP, LVAWd and LVPWd were increased (P<0.01), and LVIDd was decreased (P<0.01) in the rats of the model group. SBP, DBP, MAP and LVAWd were dropped (P<0.01, P<0.05), and LVIDd rose (P<0.01) in the EA group when compared with those in the model group. The differences in the above indexes were not statistically significant between the blocking group and the model group (P>0.05). Compared with the normal group, Hyp level and the mRNA expression of NF-κB p65, TNF-α, IL-1β and IL-6 in the myocardial tissue increased (P<0.01, P<0.05) and Ach level decreased (P<0.01) in the model group. Hyp level, the mRNA expression of NF-κB p65, TNF-α, IL-1β and IL-6 in the myocardial tissue were reduced (P<0.05, P<0.01) and Ach level rose (P<0.01) in the EA group when compared with those in the model group. These indexes were not different statistically between the blocking group and the model group (P>0.05). CONCLUSION CAP may be involved in ameliorating the pathological damage of myocardial fibrosis during EA at "Neiguan"(PC 6). The underlying effect mechanism is associated with up-regulating the neurotransmitter, Ach and down-regulating mRNA expression of NF-κB p65 and pro-inflammatory factors such as TNF-α, IL-1β and IL-6 in myocardial tissue.
Rats ; Male ; Animals ; Rats, Inbred SHR ; NF-kappa B/metabolism* ; Rats, Inbred WKY ; Electroacupuncture ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Neuroimmunomodulation ; alpha7 Nicotinic Acetylcholine Receptor ; Acetylcholine ; Fibrosis ; RNA, Messenger

It is well established that increased excitability of the presympathetic neurons in the hypothalamic paraventricular nucleus (PVN) during hypertension leads to heightened sympathetic outflow and hypertension. However, the mechanism underlying the overactivation of PVN presympathetic neurons remains unclear. This study aimed to investigate the role of endogenous corticotropin-releasing factor (CRF) on the excitability of presympathetic neurons in PVN using Western blot, arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) recording, CRISPR/Cas9 technique and patch-clamp technique. The results showed that CRF protein expression in PVN was significantly upregulated in spontaneously hypertensive rats (SHRs) compared with normotensive Wistar-Kyoto (WKY) rats. Besides, PVN administration of exogenous CRF significantly increased RSNA, heart rate and ABP in WKY rats. In contrast, knockdown of upregulated CRF in PVN of SHRs inhibited CRF expression, led to membrane potential hyperpolarization, and decreased the frequency of current-evoked firings of PVN presympathetic neurons, which were reversed by incubation of exogenous CRF. Perfusion of rat brain slices with artificial cerebrospinal fluid containing CRF receptor 1 (CRFR1) blocker, NBI-35965, or CRF receptor 2 (CRFR2) blocker, Antisauvagine-30, showed that blocking CRFR1, but not CRFR2, hyperpolarized the membrane potential and inhibited the current-evoked firing of PVN presympathetic neurons in SHRs. However, blocking CRFR1 or CRFR2 did not affect the membrane potential and current-evoked firing of presympathetic neurons in WKY rats. Overall, these findings indicate that increased endogenous CRF release from PVN CRF neurons enhances the excitability of presympathetic neurons via activation of CRFR1 in SHRs.
Rats ; Animals ; Rats, Inbred SHR ; Paraventricular Hypothalamic Nucleus/physiology* ; Receptors, Corticotropin-Releasing Hormone/metabolism* ; Rats, Inbred WKY ; Corticotropin-Releasing Hormone/metabolism* ; Neurons/physiology* ; Hypertension ; Sympathetic Nervous System

This study investigated the drug delivery performance of oral co-loaded puerarin(PUE) and daidzein(DAZ) mixed micelles(PUE/DAZ-FS/PMMs) from the perspectives of pharmacokinetics, pharmacodynamics, and tissue distribution. The changes in PUE plasma concentration in rats were evaluated based on PUE suspension, single drug-loaded micelles(PUE-FS/PMMs), and co-loaded micelles(PUE/DAZ-FS/PMMs). Spontaneously hypertensive rats(SHR) were used to monitor systolic blood pressure, diastolic blood pressure, and mean arterial pressure for 10 weeks after administration by tail volume manometry. The content of PUE in the heart, liver, spleen, lung, kidney, brain, and testes was determined using LC-MS/MS. The results showed that compared with PUE suspension and PUE-FS/PMMs, PUE/DAZ-FS/PMMs significantly increased C_(max) in rats(P<0.01) and had a relative bioavailability of 122%. The C_(max), AUC_(0-t), AUC_(0-∞), t_(1/2), and MRT of PUE/DAZ-FS/PMMs were 1.77, 1.22, 1.22, 1.17, and 1.13 times higher than those of PUE suspension, and 1.76, 1.16, 1.08, 0.84, and 0.78 times higher than those of PUE-FS/PMMs, respectively. Compared with the model control group, PUE/DAZ-FS/PMMs significantly reduced systolic blood pressure, diastolic blood pressure, and mean arterial pressure in SHR rats(P<0.05). The antihypertensive effect of PUE/DAZ-FS/PMMs was greater than that of PUE suspension, and even greater than that of PUE-FS/PMMs at high doses. Additionally, the distribution of PMMs in various tissues showed dose dependency. The distribution of PMMs in the kidney and liver, which are metabolically related tissues, was lower than that in the suspension group, while the distribution in the brain was higher than that in the conventional dose group. In conclusion, PUE/DAZ-FS/PMMs not only improved the bioavailability of PUE and synergistically enhanced its therapeutic effect but also prolonged the elimination of the drug to some extent. Furthermore, the micelles facilitated drug penetration through the blood-brain barrier. This study provides a foundation for the development of co-loaded mixed micelles containing homologous components.
Rats ; Animals ; Micelles ; Tissue Distribution ; Chromatography, Liquid ; Tandem Mass Spectrometry ; Rats, Inbred SHR ; Isoflavones/pharmacology*

OBJECTIVE: To investigate the effect of electroacupuncture (EA) at Neiguan (PC 6) on myocardial fibrosis in spontaneously hypertensive rats (SHRs), and to explore the contribution of interleukin-1 β (IL-1 β), insulin-like growth factor 1 (IGF-1), and transforming growth factor β 1 (TGF- β 1) to the effects. METHODS: Nine 12-weeks-old Wistar Kyoto (WKY) male rats were employed as the normal group. Twenty-seven SHRs were equally randomized into SHR, SHR+EA, and SHR + sham groups. EA was applied at bilateral PC 6 once a day 30 min per day in 8 consecutive weeks. After 8-weeks EA treatment at PC 6, histopathologic changes of collagen type I (Col I), collagen type 1 (Col 1) and the levels of IGF-1, 1L-1 β, TGF- β 1, matrix metalloproteinase (MMP)-2 and MMP-9 were examined in myocardial tissure respectively. RESULTS: After 8-weeks EA treatment at PC 6, the enhanced myocardial fibrosis in SHRs were characterized by the increased mean fluorescence intensity of Col I and Col 1 in myocardium tissue (P<0.01). All these abnormal alterations above in SHR + EA group was significantly lower compared with the SHR group (P<0.01). Meanwhile, the increased levels of IL-1 β, IGF-1, TGF-β 1 in serum or myocardial tissue of SHRs, diminished MMP 9 mRNA expression in SHRs were also markedly inhibited after 8 weeks of EA treatment (P<0.05 or P<0.01). Furthermore, the contents of IL-1 β, IGF-1, TGF-β 1 in myocardial tissue were positively correlated with the systolic blood pressure and hydroxyproline respectively (P<0.01). CONCLUSION EA at bilateral PC 6 could ameliorate cardiac fibrosis in SHRs, which might be mediated by regulation of 1L-1 β/IGF-1-TGF- β 1-MMP9 pathway.
Rats ; Animals ; Male ; Rats, Inbred WKY ; Electroacupuncture ; Hypertension/therapy* ; Insulin-Like Growth Factor I ; Interleukin-1beta ; Rats, Inbred SHR ; Essential Hypertension ; Myocardium/pathology* ; Collagen Type I ; Fibrosis

OBJECTIVE: To investigate the effects of different manners of heat exposure on thoracic aorta injury in spontaneously hypertensive rats (SHRs) and explore the underlying mechanism. METHODS: Normal 6 to 7-week-old male SHRs were randomized into control group (cage at room temperature), intermittent heat exposure group (SHR-8 group, exposed to 32 ℃ for 8 h daily for 7 days) and SHR-24 group (with continuous exposure to 32 ℃ for 7 days). After the treatments, the pathologies of the thoracic aorta of the rats were observed with HE staining, and the expressions of Beclin1, LC3B and p62 were detected with Western blotting and immunofluorescence assay; TUNEL staining was used to observe cell apoptosis in the thoracic aorta, and the expressions of caspase-3, Bax, and Bcl-2 were detected using Western blotting. The effects of intraperitoneal injections of 3-MA (an autophagy agonist), rapamycin (an autophagy inhibitor) or compound C 30 min before intermittent heat exposure on the expressions of proteins associated with autophagy, apoptosis and the AMPK/mTOR/ULK1 pathway in the aorta were examined with immunohistochemistry. RESULTS: In SHR-8 group, the rats showed incomplete aortic intima with disordered cell distribution and significantly increased expressions of Beclin1, LC3II/LC3I and Bax, lowered expressions of p62 and Bcl-2, and increased apoptotic cells in the thoracic aorta (P < 0.05). Pretreatment with 3-MA obviously inhibited the expressions of autophagy- and apoptosis-related proteins, whereas rapamycin promoted their expressions. Compared with the control group, the rats in SHR-8 group had significantly down-regulated p-mTOR and up-regulated p-AMPK and p-ULK1 expression of in the aorta; Treatment with compound C obviously lowered the expressions of p-AMPK and p-ULK1 and those of LC3B and Beclin1 as well. CONCLUSION In SHRs, intermittent heat exposure causes significant pathologies and promotes autophagy and apoptosis in the thoracic aorta possibly by activating the AMPK/mTOR/ULK1 pathway.
Rats ; Male ; Animals ; Rats, Inbred SHR ; AMP-Activated Protein Kinases/metabolism* ; bcl-2-Associated X Protein/metabolism* ; Aorta, Thoracic ; Beclin-1 ; Hot Temperature ; TOR Serine-Threonine Kinases/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Apoptosis ; Aortic Diseases ; Autophagy ; Autophagy-Related Protein-1 Homolog/metabolism*

OBJECTIVE: To investigate the correlation of inducible co-stimulatory molecules (ICOS) with mesenteric vascular endothelial- mesenchymal transition (EndMT) and sclerosis in spontaneously hypertensive rats (SHR). METHODS: Twenty 4-week-old WKY rats and 20 SHRs of the same strain were both randomly divided into 4 groups for observation at 4, 6, 10 and 30 weeks of age. ICOS expression frequency in rat spleen CD4⁺T cells was analyzed using flow cytometry, and the expressions of ICOS, VE-cad, α-SMA and Col3 mRNA in rat mesentery were detected by RT-PCR. The distributions of ICOS, IL-17A and TGF-β in rat mesentery were detected by immunohistochemistry. The levels of IL-17A and TGF-β in rat plasma were measured using ELISA. The morphological changes of rat mesenteric vessels were observed with Masson staining. Spearman or Pearson correlation analyses were used to evaluate the correlation between ICOS expression and the expressions of the markers of vascular EndMT and sclerosis. RESULTS: Compared with the control WKY rats, the SHRs began to show significantly increased systolic blood pressure and ICOS expression frequency on CD4⁺T cells at 6 weeks of age (P < 0.05). In the SHRs, the mRNA and protein expressions of ICOS, α-SMA, Col3, IL-17A and TGF-β in the mesentery were significantly higher than those in control group (P < 0.05), while the mRNA and protein expressions of VE-cad started to reduce significantly at 10 weeks of age (P < 0.05). The plasma levels of IL-17A and TGF-β were significantly increased in SHRs since 6 weeks of age (P < 0.05) with progressive worsening of mesenteric vascular sclerosis (P < 0.05). ICOS mRNA and protein expression levels in the mesenteric tissues of SHRs began to show positive correlations with α-SMA and Col3 expression levels and the severity of vascular sclerosis at 6 weeks of age (P < 0.05) and a negative correlation with VE-cad expression level at 10 weeks (P < 0.05). CONCLUSION ICOS play an important pathogenic role in EndMT and sclerosis of mesenteric vessels in essential hypertension by mediating related immune responses.
Rats ; Animals ; Rats, Inbred SHR ; Rats, Inbred WKY ; Hypertension ; Interleukin-17 ; Sclerosis/pathology* ; Transforming Growth Factor beta ; Mesentery/pathology* ; RNA, Messenger/metabolism* ; Blood Pressure

In the present study, the contents of seven active components [genipinic acid(GA), protocatechuic acid(PCA), neochlorogenic acid(NCA), chlorogenic acid(CA), cryptochlorogenic acid(CCA),(+)-pinoresinol di-O-β-D-glucopyranosid(PDG), and(+)-pinoresinol 4'-O-β-D-glucopyranoside(PG)] of Eucommiae Cortex in aortic vascular endothelial cells of spontaneously hypertensive rats(SHR) were simultaneously determined by ultra-high liquid chromatography-triple quadrupole mass spectrometry(UPLC-MS/MS). The qualified SHR models were selected. The primary aortic endothelial cells(VECs) of rats were separated and cultured by ligation and adherence, followed by subculture. After successful identification, an UPLC-MS/MS method for simultaneously determining the contents of GA, PCA, NCA, CA, CCA, PDG, PG in seven components of Eucommiae Cortex in VECs was established, including specificity, linearity, matrix effect, recovery, accuracy, precision and stability. The established method had the lo-west limit of quantification of 0.97-4.95 μg·L~(-1), accuracy of 87.26%-109.6%, extraction recovery of 89.23%-105.3%, matrix effect of 85.86%-106.2%, and stability of 86.00%-112.5%. Therefore, the established accurate UPLC-MS/MS method could rapidly and simultaneously determine the contents of the seven active components of Eucommiae Cortex in VECs of SHRs, which provided a refe-rence for the study of cellular pharmacokinetics of active components of Eucommiae Cortex extract.
Rats ; Animals ; Rats, Inbred SHR ; Chromatography, Liquid ; Chromatography, High Pressure Liquid/methods* ; Endothelial Cells ; Tandem Mass Spectrometry/methods*

OBJECTIVE: To explore the role of interleukin-17A (IL-17A) in renal epithelial- mesenchymal transition (EMT) in essential hypertensive nephropathy. METHODS: Four-week-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats (control group) were both randomized into 4 groups (n=5) for observation at 4, 6, 10 and 30 weeks of age. Blood pressure of the rats was monitored using a noninvasive tail artery blood pressure measurement instrument. The percentage of Th17 cells in the splenocytes was analyzed using flow cytometry. The mRNA and protein expression levels of IL-17A, iNOS, Arg-1, E-cadherin, and α-SMA in the kidneys of the rats were detected using RT-PCR and immunohistochemical staining, respectively, and plasma levels of IL-17A were regularly detected using ELISA. RESULTS: At the age of 6 weeks, the SHRs began to show significantly higher blood pressure with greater Th17 cell percentage in the splenocytes and high renal expression and plasma level of IL-17A than WKY rats (P < 0.05 or P < 0.01). At 30 weeks, renal expression of E-cadherin mRNA and protein was significantly lower and the expression of Arg-1 mRNA and protein was significantly higher in SHR than in WKY rats (P < 0.01). Compared with the WKY rats, the SHRs showed significantly higher mRNA and protein expressions of iNOS at 6 and 10 weeks (P < 0.05 or 0.01) and higher α-SMA mRNA and protein expressions since 10 weeks of age (P < 0.05 or 0.01). In SHRs older than 10 weeks, renal IL-17A mRNA and protein expression levels were negatively correlated with those of E-cadherin (r=-0.731, P < 0.05; r=-0.827, P < 0.01) and positively correlated with those of α-SMA (r=0.658, P < 0.05; r=0.968, P < 0.01). CONCLUSION IL-17A is closely correlated with the progression of renal EMT in SHR and plays its role possibly by mediating M1/M2 polarization of renal infiltrating macrophages.
Animals ; Blood Pressure ; Cadherins/metabolism* ; Epithelial-Mesenchymal Transition ; Hypertension ; Interleukin-17/metabolism* ; Kidney ; RNA, Messenger/metabolism* ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Neiguan" (PC 6) on cardiac function of ventriculus sinister in rats with spontaneously hypertensive (SHR), and to explore the mediation effect of endothelin-1 (ET-1)/endothelial nitric oxide synthase (eNOS). METHODS: Six 12-week-old male Wistar Kyoto (WKY) rats were taken as the normal group. Eighteen 12-week-old SHR were randomly divided into a model group, an EA group and a sham EA group, 6 rats in each group. The rats in the EA group were treated with EA (disperse-dense wave, 2 Hz/15 Hz in frequency, 1 mA in current intensity) at "Neiguan" (PC 6), 30 min each time, once a day for 8 weeks. The rats in the sham EA group were treated with superficial needling at "Neiguan" (PC 6) with no electrical stimulation applied. After treatment, the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were tested by echocardiographic analysis. The left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), heart rate (HR), the maximum rate of increase/decrease of left ventricular pressure (±dp/dt_max) were detected. The serum content of ET-1 was detected by ELISA. Western blot was used to evaluate the expression of ETAR, eNOS in myocardial tissue of left ventricular. RESULTS: Compared with the normal group, LVEF, LVFS, +dp/dt_max/LVSP and -dp/dt_max/LVSP were decreased (P<0.01, P<0.05), while LVSP, LVEDP, +dp/dt_max and -dp/dt_max were increased (P<0.01) in the model group. Compared with the model group, LVEF, LVFS, +dp/dt_max/LVSP and -dp/dt_max/LVSP were increased (P<0.01, P<0.05), and LVSP and LVEDP were decreased (P<0.01) in the EA group. Compared with the normal group, the serum content of ET-1 and the expression of ETAR in myocardial tissue were increased (P<0.01), whereas expression of eNOS was decreased (P<0.01) in the model group. Compared with the model group, the serum content of ET-1 and the expression of ETAR in myocardial tissue were decreased (P<0.05), whereas expression of eNOS was increased (P<0.05) in the EA group. CONCLUSION EA intervention may alleviate hypertensive cardiac function damage by up-regulating the expression of eNOS protein in myocardial tissue, down-regulating the serum content of ET-1 and the expression of ETAR protein in myocardial tissue.
Animals ; Electroacupuncture ; Endothelin-1/genetics* ; Heart Diseases ; Hypertension/therapy* ; Male ; Nitric Oxide Synthase Type III/genetics* ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Stroke Volume ; Ventricular Function, Left

OBJECTIVE: To investigate the influence of electroacupuncture (EA) on ghrelin and the phosphoinositide 3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3K/Akt/eNOS) signaling pathway in spontaneously hypertensive rats (SHRs). METHODS: Eight Wistar-Kyoto rats were used as the healthy blood pressure (BP) control (normal group), and 32 SHRs were randomized into model group, EA group, EA plus ghrelin group (EA + G group), and EA plus PF04628935 group (a potent ghrelin receptor blocker; EA + P group) using a random number table. Rats in the normal group and model group did not receive treatment, but were immobilized for 20 min per day, 5 times a week, for 4 continuous weeks. SHRs in the EA group, EA + G group and EA + P group were immobilized and given EA treatment in 20 min sessions, 5 times per week, for 4 weeks. Additionally, 1 h before EA, SHRs in the EA + G group and EA + P group were intraperitoneally injected with ghrelin or PF04628935, respectively, for 4 weeks. The tail-cuff method was used to measure BP. After the 4-week intervention, the rats were sacrificed by cervical dislocation, and pathological morphology of the abdominal aorta was observed using hematoxylin-eosin (HE) staining. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of ghrelin, nitric oxide (NO), endothelin-1 (ET-1) and thromboxane A2 (TXA2) in the serum. Isolated thoracic aortic ring experiment was performed to evaluate vasorelaxation. Western blot was used to measure the expression of PI3K, Akt, phosphorylated Akt (p-Akt) and eNOS proteins in the abdominal aorta. Further, quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to measure the relative levels of mRNA expression for PI3K, Akt and eNOS in the abdominal aorta. RESULTS: EA significantly reduced the systolic BP (SBP) and diastolic BP (DBP) (P < 0.05). HE staining showed that EA improved the morphology of the vascular endothelium to some extent. Results of ELISA indicated that higher concentrations of ghrelin and NO, and lower concentrations of ET-1 and TXA2 were presented in the EA group (P < 0.05). The isolated thoracic aortic ring experiment demonstrated that the vasodilation capacity of the thoracic aorta increased in the EA group. Results of Western blot and qRT-PCR showed that EA increased the abundance of PI3K, p-Akt/Akt and eNOS proteins, as well as expression levels of PI3K, Akt and eNOS mRNAs (P < 0.05). In the EA + G group, SBP and DBP decreased (P < 0.05), ghrelin concentrations increased (P < 0.05), and the concentrations of ET-1 and TXA2 decreased (P < 0.05), relative to the EA group. In addition, the levels of PI3K and eNOS proteins, the p-Akt/Akt ratio, and the expression of PI3K, Akt and eNOS mRNAs increased significantly in the EA + G group (P < 0.05), while PF04628935 reversed these effects. CONCLUSION EA effectively reduced BP and protected the vascular endothelium, and these effects may be linked to promoting the release of ghrelin and activation of the PI3K/Akt/eNOS signaling pathway.
Animals ; Electroacupuncture ; Ghrelin/pharmacology* ; Nitric Oxide/metabolism* ; Nitric Oxide Synthase Type III/pharmacology* ; Phosphatidylinositol 3-Kinase/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/pharmacology* ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Signal Transduction