Virtually all of the dietary potassium intake is absorbed in the intestine, over 90% of which is excreted by the kidneys regarded as the most important organ of potassium excretion in the body. The renal excretion of potassium results primarily from the secretion of potassium by the principal cells in the aldosterone-sensitive distal nephron (ASDN), which is coupled to the reabsorption of Na⁺ by the epithelial Na⁺ channel (ENaC) located at the apical membrane of principal cells. When Na⁺ is transferred from the lumen into the cell by ENaC, the negativity in the lumen is relatively increased. K⁺ efflux, H⁺ efflux, and Cl^- influx are the 3 pathways that respond to Na⁺ influx, that is, all these 3 pathways are coupled to Na⁺ influx. In general, Na⁺ influx is equal to the sum of K⁺ efflux, H⁺ efflux, and Cl^- influx. Therefore, any alteration in Na⁺ influx, H⁺ efflux, or Cl^- influx can affect K⁺ efflux, thereby affecting the renal K⁺ excretion. Firstly, Na⁺ influx is affected by the expression level of ENaC, which is mainly regulated by the aldosterone-mineralocorticoid receptor (MR) pathway. ENaC gain-of-function mutations (Liddle syndrome, also known as pseudohyperaldosteronism), MR gain-of-function mutations (Geller syndrome), increased aldosterone levels (primary/secondary hyperaldosteronism), and increased cortisol (Cushing syndrome) or deoxycorticosterone (hypercortisolism) which also activate MR, can lead to up-regulation of ENaC expression, and increased Na⁺ reabsorption, K⁺ excretion, as well as H⁺ excretion, clinically manifested as hypertension, hypokalemia and alkalosis. Conversely, ENaC inactivating mutations (pseudohypoaldosteronism type 1b), MR inactivating mutations (pseudohypoaldosteronism type 1a), or decreased aldosterone levels (hypoaldosteronism) can cause decreased reabsorption of Na⁺ and decreased excretion of both K⁺ and H⁺, clinically manifested as hypotension, hyperkalemia, and acidosis. The ENaC inhibitors amiloride and Triamterene can cause manifestations resembling pseudohypoaldosteronism type 1b; MR antagonist spironolactone causes manifestations similar to pseudohypoaldosteronism type 1a. Secondly, Na⁺ influx is regulated by the distal delivery of water and sodium. Therefore, when loss-of-function mutations in Na⁺-K⁺-2Cl^- cotransporter (NKCC) expressed in the thick ascending limb of the loop and in Na⁺-Cl^- cotransporter (NCC) expressed in the distal convoluted tubule (Bartter syndrome and Gitelman syndrome, respectively) occur, the distal delivery of water and sodium increases, followed by an increase in the reabsorption of Na⁺ by ENaC at the collecting duct, as well as increased excretion of K⁺ and H⁺, clinically manifested as hypokalemia and alkalosis. Loop diuretics acting as NKCC inhibitors and thiazide diuretics acting as NCC inhibitors can cause manifestations resembling Bartter syndrome and Gitelman syndrome, respectively. Conversely, when the distal delivery of water and sodium is reduced (e.g., Gordon syndrome, also known as pseudohypoaldosteronism type 2), it is manifested as hypertension, hyperkalemia, and acidosis. Finally, when the distal delivery of non-chloride anions increases (e.g., proximal renal tubular acidosis and congenital chloride-losing diarrhea), the influx of Cl^- in the collecting duct decreases; or when the excretion of hydrogen ions by collecting duct intercalated cells is impaired (e.g., distal renal tubular acidosis), the efflux of H⁺ decreases. Both above conditions can lead to increased K⁺ secretion and hypokalemia. In this review, we focus on the regulatory mechanisms of renal potassium excretion and the corresponding diseases arising from dysregulation.
Humans ; Bartter Syndrome/metabolism* ; Pseudohypoaldosteronism/metabolism* ; Potassium/metabolism* ; Aldosterone/metabolism* ; Hypokalemia/metabolism* ; Gitelman Syndrome/metabolism* ; Hyperkalemia/metabolism* ; Clinical Relevance ; Epithelial Sodium Channels/metabolism* ; Kidney Tubules, Distal/metabolism* ; Sodium/metabolism* ; Hypertension ; Alkalosis/metabolism* ; Water/metabolism* ; Kidney/metabolism*

Heart failure with preserved ejection fraction (HFpEF) is a type of heart failure characterized by left ventricular diastolic dysfunction with preserved ejection fraction. With the aging of the population and the increasing prevalence of metabolic diseases, such as hypertension, obesity and diabetes, the prevalence of HFpEF is increasing. Compared with heart failure with reduced ejection fraction (HFrEF), conventional anti-heart failure drugs failed to reduce the mortality in HFpEF due to the complex pathophysiological mechanism and multiple comorbidities of HFpEF. It is known that the main changes of cardiac structure of in HFpEF are cardiac hypertrophy, myocardial fibrosis and left ventricular hypertrophy, and HFpEF is commonly associated with obesity, diabetes, hypertension, renal dysfunction and other diseases, but how these comorbidities cause structural and functional damage to the heart is not completely clear. Recent studies have shown that immune inflammatory response plays a vital role in the progression of HFpEF. This review focuses on the latest research progress in the role of inflammation in the process of HFpEF and the potential application of anti-inflammatory therapy in HFpEF, hoping to provide new research ideas and theoretical basis for the clinical prevention and treatment in HFpEF.
Humans ; Heart Failure ; Stroke Volume/physiology* ; Hypertrophy, Left Ventricular/metabolism* ; Ventricular Dysfunction, Left/metabolism* ; Inflammation/complications* ; Obesity ; Hypertension

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

In this study, we investigated the effects of Panax notoginseng saponins (PNS) on pulmonary vascular remodeling and ADAM10/Notch3 pathway in pulmonary arterial hypertension (PAH). PAH rat model was established, and male Sprague Dawley (SD) rats were randomly divided into control group, monocrotaline (MCT) group and MCT+PNS group, with 10 rats in each group. Rats in the control group were intraperitoneally injected with equal volume of normal saline. Rats in the MCT group was injected intraperitoneally with 60 mg/kg MCT on the first day, and then with the same volume of normal saline every day. Rats in the MCT+PNS group was injected intraperitoneally with 60 mg/kg MCT on the first day, and then with 50 mg/kg PNS every day. The modeling time of each group lasted for 21 days. After the model was established, the mean pulmonary artery pressure (mPAP) was measured by right heart catheterization technique, the right ventricular hypertrophy index (RVHI) was calculated, the microscopic morphology and changes of pulmonary vascular wall were observed by HE and Masson staining, and the expressions of ADAM10, Notch3, Hes-1, P27, PCNA, Caspase-3 proteins and mRNA in pulmonary vascular tissue of rats were detected by Western blot and qPCR. The expression and localization of Notch3 and α-SMA were detected by immunofluorescence staining. The protein expression of ADAM10 was detected by immunohistochemical staining. The results showed that compared with the control group, mPAP, RVHI, pulmonary vessels and collagen fibers in the MCT group were significantly increased, the expressions of ADAM10, Notch3, Hes-1, and PCNA protein and mRNA were significantly increased, while the expressions of P27 and Caspase-3 protein and mRNA were decreased significantly. Compared with the MCT group, mPAP and RVHI were significantly decreased, pulmonary vessels were significantly improved and collagen fibers were significantly reduced, the expressions of protein and mRNA of ADAM10, Notch3, Hes-1, and PCNA were decreased in MCT+PNS group, but the expressions of protein and mRNA of P27 and Caspase-3 were increased slightly. The results of immunofluorescence showed that Notch3 and α-SMA staining could overlap, which proved that Notch3 was expressed in smooth muscle cells. The expression of Notch3 in the MCT group was increased significantly compared with that in the control group, while PNS intervention decreased the expression of Notch3. Immunohistochemical staining showed that compared with the control group, the amount of ADAM10 in the MCT group was increased significantly, and the expression of ADAM10 in the MCT+PNS group was decreased compared with the MCT group. These results indicate that PNS can improve the PAH induced by MCT in rats by inhibiting ADAM10/Notch3 signaling pathway.
Animals ; Male ; Rats ; Caspase 3/metabolism* ; Collagen ; Disease Models, Animal ; Hypertension, Pulmonary/drug therapy* ; Monocrotaline/adverse effects* ; Panax notoginseng/chemistry* ; Proliferating Cell Nuclear Antigen/pharmacology* ; Pulmonary Arterial Hypertension ; Pulmonary Artery/metabolism* ; Rats, Sprague-Dawley ; Receptor, Notch3/genetics* ; RNA, Messenger ; Saline Solution ; Signal Transduction ; Saponins/pharmacology*

OBJECTIVE: To study effects of Shenmai Injection on hypertensive heart failure and its mechanism for inhibiting myocardial fibrosis. METHODS: Salt-sensitive (Dahl/SS) rats were fed with normal diet (0.3% NaCl) and the high-salt diet (8% NaCl) to observe the changes in blood pressure and heart function, as the control group and the model group. Salt-insensitive rats (SS-13BN) were fed with the high-salt diet (8% NaCl) as the negative control group. After modeling, the model rats were randomly divided into heart failure (HF) group, Shenmai Injection (SMI) group and pirfenidone (PFD) group by a random number table, with 6 rats in each group. They were given sterilized water, SMI and pirfenidone, respectively. Blood pressure, cardiac function, fibrosis and related molecular expression were detected by sphygmomanometer, echocardiogram, enzyme linked immunosorbent assay (ELISA), hematoxylin-eosin staining, Masson staining, immunofluorescence and qPCR analysis. RESULTS: After high-salt feeding, compared with the control and negative control group, in the model group the blood pressure increased significantly, the left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were significantly reduced, and the serum NT-proBNP concentration increased significantly (all P<0.05); furthermore, the arrangement of myocardial cells was disordered, the edema was severe, and the degree of myocardial fibrosis was also significantly increased (P<0.05); the protein and mRNA expressions of collagen type I (Col I) were up-regulated (P<0.05), and the mRNA expressions of transforming growth factor β 1 (TGF- β 1), Smad2 and Smad3 were significantly up-regulated (P<0.05). Compared with HF group, after intervention of Shenmai Injection, LVEF and LVFS increased, myocardial morphology was improved, collagen volume fraction decreased significantly (P<0.05), and the mRNA expressions of Col I, TGF- β 1, Smad2 and Smad3, as well as Col I protein expression, were all significantly down-regulated (all P<0.05). CONCLUSION Myocardial fibrosis is the main pathological manifestation of hypertensive heart failure, and Shenmai Injection could inhibit myocardial fibrosis and effectively improve heart failure by regulating TGF-β 1/Smad signaling pathway.
Rats ; Animals ; Stroke Volume ; Sodium Chloride ; Rats, Inbred Dahl ; Ventricular Function, Left ; Heart Failure ; Transforming Growth Factor beta1/metabolism* ; Hypertension ; Fibrosis ; RNA, Messenger

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

Humans ; Pulmonary Arterial Hypertension ; Bone Morphogenetic Protein Receptors, Type II/metabolism* ; Pedigree ; Mutation ; Familial Primary Pulmonary Hypertension

Objective To explore the roles of different insulin resistance indexes[triglyceride-glucose (TyG),triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C),and metabolic score for insulin resistance (METS-IR)]and combinations of two indexes in predicting diabetes risk in hypertensive population. Methods The survey of hypertension was conducted for the residents in Wuyuan county,Jiangxi province from March to August in 2018.The basic information of hypertensive residents was collected by interview.Blood was drawn on an empty stomach in the morning and physical measurements were carried out.Logistic regression model was employed to analyze the relationship between different insulin resistance indexes and diabetes,and the area under the receiver operating characteristic curve was used for evaluating the predictive effects of each index on diabetes risk. Results A total of 14 222 hypertensive patients with an average age of (63.8±9.4) years old were included in this study,including 2616 diabetic patients.The diabetic hypertensive population had higher TyG (t=50.323,P<0.001),TG/HDL-C (Z=17.325,P<0.001),and METS-IR (t=28.839,P<0.001) than the non-diabetic hypertensive population.Multivariate analysis showed that each insulin resistance index was positively correlated with diabetes risk.The area under curve of each insulin index was in a descending order of TyG (0.770)> METS-IR (0.673)> TG/HDL-C (0.620).The difference in the area under curve between two indexes was statistically significant[TyG vs.TG/HDL-C (Z=42.325,P<0.001);TyG vs.METS-IR(Z=17.517,P<0.001);METS-IR vs.TG/HDL-C (Z=10.502,P<0.001)]. Conclusions Elevated insulin resistance indexes can increase the risk of diabetes.TyG and the combination of indexes outperform TG/HDL-C and METS-IR in the prediction of diabetes.
Humans ; Middle Aged ; Aged ; Insulin Resistance ; Blood Glucose/metabolism* ; Biomarkers ; Diabetes Mellitus ; Hypertension ; Glucose ; Triglycerides ; Cholesterol, HDL

Objective To explore the relationship between insulin resistance (IR) indexes and hyperuricemia (HUA) among the people with hypertension. Methods From July to August in 2018,hypertension screening was carried out in Wuyuan county,Jiangxi province,and the data were collected through questionnaire survey,physical measurement,and biochemical test.Logistic regression was performed to analyze the relationship between HUA and IR indexes including metabolic score for IR (METS-IR),triglyceride-glucose (TyG) index,TyG-body mass index (BMI),TyG-waist circumference (WC),visceral adiposity index (VAI),triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C),and lipid accumulation product (LAP).The penalty spline method was used for the curve fitting between IR indexes and HUA.The area under the receiver operating characteristic curve (AUC) was employed to reveal the correlation between each index and HUA. Results The 14 220 hypertension patients included 6 713 males and 7 507 females,with the average age of (63.8±9.4) years old,the average uric acid level of (418.9±120.6) mmol/L,and the HUA detection rate of 44.4%.The HUA group had higher proportions of males,current drinking,current smoking,diabetes,and using antihypertensive drugs,older age,higher diastolic blood pressure,WC,BMI,homocysteine,total cholesterol,TG,low-density lipoprotein cholesterol,blood urea nitrogen,creatinine,aspartate aminotransferase,alanine aminotransferase,total protein,albumin,total bilirubin,direct bilirubin, METS-IR, TyG, TyG-BMI, TyG-WC, VAI, TG/HDL-C, and LAP, and lower systolic blood pressure and HDL-C than the normal uric acid group (all P<0.05).Multivariate Logistic regression showed that METS-IR (OR=1.049,95%CI=1.038-1.060, P<0.001), TyG (OR=1.639,95%CI=1.496-1.797, P<0.001), TyG-BMI (OR=1.008,95%CI=1.006-1.010, P<0.001), TyG-WC (OR=1.003,95%CI=1.002-1.004, P<0.001), lnVAI (OR=1.850, 95%CI=1.735-1.973, P<0.001), ln(TG/HDL-C) (OR=1.862,95%CI=1.692-2.048, P<0.001),and lnLAP (OR=1.503,95%CI=1.401-1.613,P<0.001) were associated with the risk of HUA.Curve fitting indicated that METS-IR,TyG,TYG-BMI,TYG-WC,lnVAI,ln(TG/HDL-C),and lnLAP were positively correlated with HUA (all P<0.001),and the AUC of TyG index was higher than that of other IR indexes (all P<0.05). Conclusion Increased IR indexes,especially TyG,were associated with the risk of HUA among people with hypertension.
Male ; Female ; Humans ; Middle Aged ; Aged ; Insulin Resistance ; Hyperuricemia ; Uric Acid ; Hypertension/complications* ; Glucose ; Obesity, Abdominal/epidemiology* ; Triglycerides ; Bilirubin ; Cholesterol ; Blood Glucose/metabolism*

OBJECTIVES: To study the effect of platelet-derived growth factor-BB (PDGF-BB) on pulmonary vascular remodeling in neonatal rats with hypoxic pulmonary hypertension (HPH). METHODS: A total of 128 neonatal rats were randomly divided into four groups: PDGF-BB+HPH, HPH, PDGF-BB+normal oxygen, and normal oxygen (n=32 each). The rats in the PDGF-BB+HPH and PDGF-BB+normal oxygen groups were given an injection of 13 μL 6×10¹⁰ PFU/mL adenovirus with PDGF-BB genevia the caudal vein. After 24 hours of adenovirus transfection, the rats in the HPH and PDGF-BB+HPH groups were used to establish a neonatal rat model of HPH. Right ventricular systolic pressure (RVSP) was measured on days 3, 7, 14, and 21 of hypoxia. Hematoxylin-eosin staining was used to observe pulmonary vascular morphological changes under an optical microscope, and vascular remodeling parameters (MA% and MT%) were also measured. Immunohistochemistry was used to measure the expression levels of PDGF-BB and proliferating cell nuclear antigen (PCNA) in lung tissue. RESULTS: The rats in the PDGF-BB+HPH and HPH groups had a significantly higher RVSP than those of the same age in the normal oxygen group at each time point (P<0.05). The rats in the PDGF-BB+HPH group showed vascular remodeling on day 3 of hypoxia, while those in the HPH showed vascular remodeling on day 7 of hypoxia. On day 3 of hypoxia, the PDGF-BB+HPH group had significantly higher MA% and MT% than the HPH, PDGF-BB+normal oxygen, and normal oxygen groups (P<0.05). On days 7, 14, and 21 of hypoxia, the PDGF-BB+HPH and HPH groups had significantly higher MA% and MT% than the PDGF-BB+normal oxygen and normal oxygen groups (P<0.05). The PDGF-BB+HPH and HPH groups had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group at all time points (P<0.05). On days 3, 7, and 14 of hypoxia, the PDGF-BB+HPH group had significantly higher expression levels of PDGF-BB and PCNA than the HPH group (P<0.05), while the PDGF-BB+normal oxygen group had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group (P<0.05). CONCLUSIONS Exogenous administration of PDGF-BB in neonatal rats with HPH may upregulate the expression of PCNA, promote pulmonary vascular remodeling, and increase pulmonary artery pressure.
Rats ; Animals ; Hypertension, Pulmonary ; Becaplermin ; Animals, Newborn ; Proliferating Cell Nuclear Antigen ; Vascular Remodeling ; Pulmonary Artery/metabolism* ; Hypoxia ; Oxygen ; Cell Proliferation ; Myocytes, Smooth Muscle/metabolism*