The renin angiotensin system (RAS) appears to influence male fertility at multiple levels. In this work, we analyzed the relationship between the RAS and DNA integrity. Fifty male volunteers were divided into two groups (25 each): control (DNA fragmentation ≤20%) and pathological (DNA fragmentation >20%) cases. Activities of five peptidases controlling RAS were measured fluorometrically: prolyl endopeptidase (which converts angiotensin [A] I and A II to A 1-7), neutral endopeptidase (NEP/CD10: A I to A 1-7), aminopeptidase N (APN/CD13: A III to A IV), aminopeptidase A (A II to A III) and aminopeptidase B (A III to A IV). Angiotensin-converting enzyme (A I to A II), APN/CD13 and NEP/CD10 were also assessed by semiquantitative cytometry and quantitative flow cytometry assays, as were the receptors of all RAS components: A II receptor type 1 (AT1R), A II receptor type 2 (AT2R), A IV receptor (AT4R or insulin-regulated aminopeptidase [IRAP]), (pro)renin receptor (PRR) and A 1-7 receptor or Mas receptor (MasR) None of the enzymes that regulate levels of RAS components, except for APN/CD13 (decrease in fragmented cells), showed significant differences between both groups. Micrographs of RAS receptors revealed no significant differences in immunolabeling patterns between normozoospermic and fragmented cells. Labeling of AT1R (94.3% normozoospermic vs 84.1% fragmented), AT4R (96.2% vs 95.3%) and MasR (97.4% vs 87.2%) was similar between the groups. AT2R (87.4% normozoospermic vs 63.1% fragmented) and PRR (96.4% vs 48.2%) were higher in non-fragmented spermatozoa. These findings suggest that fragmented DNA spermatozoa have a lower capacity to respond to bioactive RAS peptides.
Angiotensins ; DNA Fragmentation ; Humans ; Insulin ; Male ; Renin-Angiotensin System/physiology* ; Spermatozoa

Renin-angiotensin system (RAS) is involved in the regulation of vascular smooth muscle cell (VSMC) tension. Angiotensin II (Ang II) as the main effector molecule of RAS can increase the intracellular Ca concentration and cause VSMCs contraction by activating angiotensin II type 1 receptor (AT1R). The large-conductance Ca- and voltage-activated potassium (BK) channel is an essential potassium channel in VSMCs, playing an important role in maintaining membrane potential and intracellular potassium-calcium balance. The BK channel in VSMCs mainly consists of α and β1 subunits. Functional BKα subunits contain voltage-sensors and Ca binding sites. Hence, increase in the membrane potential or intracellular Ca concentration can trigger the opening of the BK channel by mediating transient K outward current in a negative regulatory manner. However, increasing evidence has shown that although Ang II can raise the intracellular Ca concentration, it also inhibits the expression and function of the BK channel by activating the PKC pathway, internalizing AT1R-BKα heterodimer, or dissociating α and β1 subunits. Under some specific conditions, Ang II can also activate the BK channel, but the underlying mechanism remains unknown. In this review, we summarize the potential mechanisms underlying the inhibitory or activating effect of Ang II on the BK channel, hoping that it could provide a theoretical basis for improving intracellular ion imbalance.
Angiotensin II ; physiology ; Calcium ; physiology ; Humans ; Large-Conductance Calcium-Activated Potassium Channels ; physiology ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; physiology ; Renin-Angiotensin System

OBJECTIVETo investigate renal artery injury caused by Kawasaki disease (KD).

METHODSForty-three children with KD were enrolled in the study. According to the blood pressure in the acute stage, these children were classified into normal blood pressure subgroup and increased blood pressure subgroup. Eighteen children with fever caused by acute upper respiratory tract infection were enrolled as the control group. The diameter of the origin of the main renal artery, hemodynamic parameters of the main renal artery and the renal interlobar artery, rennin activity, and levels of angiotensin II and aldosterone were compared between groups.

RESULTSDuring the acute stage of KD, both subgroups had a significantly smaller diameter of the origin of the main renal artery, a significantly higher resistance index (RI) of the main renal artery, and a significantly lower end-diastolic velocity (EDV) than the control group (P<0.05).The increased blood pressure subgroup had a significantly lower EDV of the interlobar artery than the normal blood pressure subgroup, a significantly higher RI than the normal blood pressure subgroup and the control group, as well as a significantly higher rennin activity and significantly higher levels of angiotensin II and aldosterone than the normal blood pressure subgroup (P<0.05). A significantly increased EDV and a significantly reduced RI of the renal interlobar artery were observed in the increased blood pressure subgroup in the subacute stage compared with the acute stage (P<0.05).

CONCLUSIONSKD may cause renal artery injury and early hemodynamic changes, resulting in a transient increase in blood pressure in some patients.

Blood Flow Velocity ; Blood Pressure ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Mucocutaneous Lymph Node Syndrome ; physiopathology ; Renal Artery ; physiopathology ; Renin-Angiotensin System ; physiology ; Vascular Resistance

The present study was aimed to investigate the roles of renal sympathetic nerve and oxidative stress in the development of foot shock-induced hypertension. Ninety rats were divided into 6 groups (the number of each group was 15): control group, foot shock group, denervation of renal sympathetic nerve group, denervation of renal sympathetic nerve + foot shock group, Tempol treatment + foot shock group, denervation of renal sympathetic nerve + Tempol treatment + foot shock group. Rats were received electrical foot shock for 14 days (2-4 mA, 75 V, shocks of 50-100 ms every 30 s, for 4 h each session through an electrified grid floor every day). Renal sympathetic ablation was used to remove bilateral renal sympathetic nerve in rats (rats were allowed to recover for one week before the beginning of the foot shock procedure). The antioxidant Tempol was injected intraperitoneally at 1 h before foot shock. Systolic blood pressure was measured at 1 h after foot shock on day 0, 3, 7, 10 and 14. Contents of thiobarbituric acid reactive substance (TBARS), renin, angiotensin II (AngII) and glutathione peroxidase (GSH-Px) in plasma were measured by ELISA after 14-day foot shock. The results showed that systolic blood pressure of foot shock group was significantly increased (P < 0.05) compared with that of control group from day 7 to day 14 of foot shock. Denervation of renal sympathetic nerve and/or Tempol treatment significantly reduced the increase of systolic blood pressure induced by foot shock. Levels of TBARS, renin and AngII in plasma were increased significantly in foot shock group compared with that of control group (P < 0.05). Plasma GSH-Px concentration was decreased in foot shock group rats compared with that of control group (P < 0.05). Denervation of renal sympathetic nerve and/or tempol treatment significantly reduced the increase in TBARS, renin, AngII levels induced by foot shock in comparison with that of foot shock group (P < 0.05), but had no effects on the reduction of GSH-Px concentration. The results suggest that renal sympathetic nerve may play an important role in the development of foot shock-induced hypertension, and renal sympathetic nerve may influence oxidative stress and directly or indirectly activate renin-angiotensin-aldosterone system, so the foot shock-induced high blood pressure may be maintained and hypertension may therefore be produced.
Animals ; Antioxidants ; pharmacology ; Blood Pressure ; Cyclic N-Oxides ; pharmacology ; Denervation ; Electric Stimulation ; Hypertension ; physiopathology ; Kidney ; innervation ; Oxidative Stress ; Rats ; Renin-Angiotensin System ; Spin Labels ; Sympathetic Nervous System ; physiology

Leptin is a protein hormone produced mainly by obese gene and secreted by adipose tissue and exerts the biological effects through leptin receptors. With the progress in research on the function and receptor signal transduction related leptin and leptin resistance, it has been found that leptin is associated with the development and progression of many cardiovascular diseases, such as hypertension and left ventricular hypertrophy. Some studies have reported that leptin resistance is the pathologic basis for a variety of cardiovascular diseases. This paper will briefly review the advances in the study of correlation between leptin and hypertensive-left ventricular hypertrophy (HLVH), focusing on the relationship between leptin and various factors related to HLVH, such as sympathetic nervous system, renin angiotensin aldosterone system, growth factors, inflammatory factors and insulin resistance.
Adipose Tissue ; Cardiovascular Diseases ; Humans ; Hypertension ; Hypertrophy, Left Ventricular ; Insulin Resistance ; Leptin ; physiology ; Receptors, Leptin ; Renin-Angiotensin System ; Sympathetic Nervous System

Vitamin D is essential for maintaining calcium and phosphate homeostasis, and vitamin D analogues have been prescribed to treat osteoporosis and hyperparathyroidism. Emerging evidence suggests that cardiovascular and chronic kidney diseases are closely associated with vitamin D deficiency resulting from either decreased sunshine exposure or inadequate intake. Vitamin D is through stimulating vitamin D receptor to form a transcriptional complex with cofactors to modulate approximately 3% gene transcription. For example, renin, matrix metalloprotease, and tumor necrosis factor-α are regulated by vitamin D. Both experimental and clinical studies support the health benefits of vitamin D in the cardiovascular system, and such benefits include protecting cardiac function, lowering blood pressure, improving endothelial function, inhibiting oxidative stress, and reducing the activity of renin-angiotensin system. This article will briefly review the cardiovascular benefits of vitamin D and its bioactive analogues and discuss the novel cellular and molecular mechanisms accounting for cardiovascular protection.
Blood Pressure ; Calcium ; physiology ; Cardiovascular Diseases ; physiopathology ; Cardiovascular Physiological Phenomena ; Endothelium, Vascular ; physiology ; physiopathology ; Humans ; Oxidative Stress ; Receptors, Calcitriol ; physiology ; Renin-Angiotensin System ; Vitamin D ; analogs & derivatives ; physiology ; Vitamin D Deficiency ; physiopathology

It is not well described the pathophysiology of renal injuries caused by a high salt intake in humans. The authors analyzed the relationship between the 24-hr urine sodium-to-creatinine ratio (24HUna/cr) and renal injury parameters such as urine angiotensinogen (uAGT/cr), monocyte chemoattractant peptide-1 (uMCP1/cr), and malondialdehyde-to-creatinine ratio (uMDA/cr) by using the data derived from 226 hypertensive chronic kidney disease patients. At baseline, the 24HUna/cr group or levels had a positive correlation with uAGT/cr and uMDA/cr adjusted for related factors (P<0.001 for each analysis). When we estimated uAGT/cr in the 24HUna/cr groups by ANCOVA, the uAGT/cr in patients with > or =200 mEq/g cr was higher than in patients with <100 mEq/g cr (708 [95% CI, 448-967] vs. 334 [95% CI, 184-483] pg/mg cr, P=0.014). Similarly, uMDA/cr was estimated as 0.17 (95% CI, 0.14-0.21) pM/mg cr in patients with <100 mEq/g cr and 0.27 (95% CI, 0.20-0.33) pM/mg cr in patients with > or =200 mEq/g cr (P=0.016). During the 16-week follow-up period, an increase in urinary sodium excretion predicted an increase in urinary angiotensinogen excretion. In conclusion, high salt intake increases renal renin-angiotensin-system (RAS) activation, primarily, and directly or indirectly affects the production of reactive oxygen species through renal RAS activation.
Adult ; Aged ; Angiotensinogen/urine ; Chemokine CCL2/urine ; Creatine/urine ; Demography ; Female ; Follow-Up Studies ; Humans ; Hypertension/complications ; Male ; Malondialdehyde/urine ; Middle Aged ; Reactive Oxygen Species/*metabolism ; Renal Insufficiency, Chronic/complications/*pathology ; Renin-Angiotensin System/*physiology ; Sodium, Dietary/*urine ; Urine Specimen Collection

OBJECTIVETo review the advances of studies on vitamin D receptor and its role in the pathogenesis of diabetic nephropathy.

DATA SOURCESA comprehensive search of the PubMed literatures without restriction on the publication date was carried out using keywords such as vitamin D receptor and diabetic nephropathy.

STUDY SELECTIONArticles related to vitamin D receptor and diabetic nephropathy were selected and carefully analyzed.

RESULTSThe ligands as well as construction and tissue distribution of vitamin D receptor were summarized. Pathogenesis of diabetic nephropathy was analyzed. The mechanisms underlying the renoprotective role of vitamin D receptor including inhibition of renin-angiotensin system, anti-inflammation, anti-fibrosis and the reduction of proteinuria were reviewed. Mounting evidences from animal and clinical studies have suggested that vitamin D therapy has beneficial effects on the renal systems and the underlying renoprotective mechanisms of the vitamin D receptor-mediated signaling pathways is a hot research topic.

CONCLUSIONOur study suggests that vitamin D receptor has a great potential for preventing the progression of diabetic nephropathy via multiple mechanisms.

Animals ; Diabetic Nephropathies ; metabolism ; Humans ; Proteinuria ; metabolism ; Receptors, Calcitriol ; metabolism ; Renin-Angiotensin System ; physiology

The present study was designed to test the hypothesis that a medium-term simulated microgravity can induce region-specific remodeling in large elastic arteries with their innermost smooth muscle (SM) layers being most profoundly affected. The second purpose was to examine whether these changes can be prevented by a simulated intermittent artificial gravity (IAG). The third purpose was to elucidate whether vascular local renin-angiotensin system (L-RAS) plays an important role in the regional vascular remodeling and its prevention by the gravity-based countermeasure. This study consisted of two interconnected series of in-vivo and ex-vivo experiments. In the in-vivo experiments, the tail-suspended, hindlimb unloaded rat model was used to simulate microgravity-induced cardiovascular deconditioning for 28 days (SUS group); and during the simulation period, another group was subjected to daily 1-hour dorso-ventral (-G(x)) gravitation provided by restoring to normal standing posture (S + D group). The activity of vascular L-RAS was evaluated by examining the gene and protein expression of angiotensinogen (Ao) and angiotensin II receptor type 1 (AT1R) in the arterial wall tissue. The results showed that SUS induced an increase in the media thickness of the common carotid artery due to hypertrophy of the four SM layers and a decrease in the total cross-sectional area of the nine SM layers of the abdominal aorta without significant change in its media thickness. And for both arteries, the most prominent changes were in the innermost SM layers. Immunohistochemistry and in situ hybridization revealed that SUS induced an up- and down-regulation of Ao and AT1R expression in the vessel wall of common carotid artery and abdominal aorta, respectively, which was further confirmed by Western blot analysis and real time PCR analysis. Daily 1-hour restoring to normal standing posture over 28 days fully prevented these remodeling and L-RAS changes in the large elastic arteries that might occur due to SUS alone. In the ex-vivo experiments, to elucidate the important role of transmural pressure in vascular regional remodeling and differential regulation of L-RAS activity, we established an organ culture system in which rat common carotid artery, held at in-vivo length, can be perfused and pressurized at varied flow and pressure for 7 days. In arteries perfused at a flow rate of 7.9 mL/min and pressurized at 150 mmHg, but not at 0 or 80 mmHg, for 3 days led to an augmentation of c-fibronectin (c-FN) expression, which was also more markedly expressed in the innermost SM layers, and an increase in Ang II production detected in the perfusion fluid. However, the enhanced c-FN expression and increased Ang II production that might occur due to a sustained high perfusion pressure alone were fully prevented by daily restoration to 0 or 80 mmHg for a short duration. These findings from in-vivo and ex-vivo experiments have provided evidence supporting our hypothesis that redistribution of transmural pressures might be the primary factor that initiates region-specific remodeling of arteries during microgravity and the mechanism of IAG is associated with an intermittent restoration of the transmural pressures to their normal distribution. And they also provide support to the hypothesis that L-RAS plays an important role in vascular adaptation to microgravity and its prevention by the IAG countermeasure.
Angiotensinogen ; genetics ; metabolism ; Animals ; Aorta, Abdominal ; pathology ; physiopathology ; Carotid Artery, Common ; pathology ; physiopathology ; Hindlimb Suspension ; Male ; Muscle, Smooth, Vascular ; metabolism ; pathology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Angiotensin, Type 1 ; genetics ; metabolism ; Renin-Angiotensin System ; physiology ; Weightlessness Simulation

OBJECTIVETo investigate the gender differences in perinatal high-salt diet programming of blood pressure and salt sensitivity in offspring Sprague-Dawley rats and explore the mechanisms.

METHODSThe rats were fed with high-salt diet (8% NaCl) or normal salt diet (1% NaCl) during the perinatal period. Body weight changes were monitored, and blood pressure and heart rate were measured by non-invasive tail-cuff methods in both male and female offspring rats. The components of renin-angiotensin-aldosterone system (RAAS) in both the serum and brain tissue, and hormones related with stress reaction were detected using radioimmunology methods.

RESULTSPerinatal high-salt diet did not affect adolescent blood pressure in both genders, but significantly increased salt sensitivity in male offspring rats. Perinatal high-salt diet also increased serum angiotensin II (ANG II) while decreased corticotropin-releasing hormone (CRH) and cortisol in male offsprings, as compared with the normal salt diet group. No similar results were found in the female offspring rats.

CONCLUSIONThere is a significant gender difference in perinatal high-salt diet programming of offspring blood pressure salt sensitivity, and the mechanisms may involve the disturbance of the RAAS function and stress reaction.

Animals ; Animals, Newborn ; Blood Pressure ; drug effects ; physiology ; Female ; Hypertension ; physiopathology ; Male ; Rats ; Rats, Sprague-Dawley ; Renin-Angiotensin System ; drug effects ; physiology ; Sex Factors ; Sodium, Dietary ; administration & dosage ; adverse effects