Angiotensin II ; physiology ; Ascites ; etiology ; Humans ; Hypertension, Portal ; etiology ; Liver Cirrhosis ; etiology ; Renin-Angiotensin System ; physiology

Renin-angiotensin system (RAS) has been shown to be involved in the growth, production, proliferation and differentiation of the bone marrow (BM) hematopoietic cells, while aplastic anemia (AA) is a disease in which proliferation ability of the BM hematopoietic cells is damaged with defective hematopoietic microenvironment. To investigated the pathogenesis of AA, the rennin activity, angiotensin I (Ang I) and angiotensin II (Ang II) concentration in peripheral blood and BM of 22 AA patients were detected by radioimmunoassay, 16 nonhematological disease patients with normal blood counts and BM picture were used as control, and the difference between two groups was compared. The results showed that BM Ang II concentration in the AA patients was significantly lower than that in the control (P < 0.01). In nonhematological disease patients, Ang II concentration in BM was significantly higher than that in peripheral blood, the renin activities and Ang I concentrations were not significantly different in the two groups (P > 0.05). In conclusion, the decreased BM Ang II concentration in AA patients may be involved to the pathogenesis of AA.
Adolescent ; Adult ; Anemia, Aplastic ; etiology ; physiopathology ; Angiotensin II ; analysis ; Bone Marrow Cells ; chemistry ; cytology ; physiology ; Female ; Hematopoiesis ; physiology ; Humans ; Male ; Middle Aged ; Renin ; analysis ; Renin-Angiotensin System ; physiology

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 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

The circulating renin-angiotensin system (RAS) is well known for its role in the maintenance of blood pressure and electrolyte and fluid homeostasis. However, other local angiotensin-generating systems than the circulating RAS have been found in numerous tissues. The male reproductive system including the testis, epididymis, and prostate has several sites of intrinsic RAS activity. The local RAS in these tissues can be responsive to androgens, fat acid, drugs, and hypoxia. There has been evidence for the involvement of the RAS not only in male reproduction, but also in the development of prostate disease. Besides, the assessment of the local RAS activity may be helpful to the early diagnosis of tumor in the male reproductive system.
Animals ; Early Diagnosis ; Genital Neoplasms, Male ; diagnosis ; Genitalia, Male ; metabolism ; physiology ; Humans ; Male ; Rats ; Renin-Angiotensin System ; physiology

OBJECTIVETo investigate the variation of seminal plasma angiotension II (Ang II) in infertile men and its clinical implication.

METHODSAng II values in paired blood plasma and seminal plasma from 43 infertile men(13 azoospermia, 8 asthenozoopermia, 17 asthenozoospermia and 5 cases with normal semen parameters) and 10 normal controls were obtained by SPE-HPLC-RIA. All semen samples with spermatozoa were analyzed by CASA for sperm count, motility and other parameters. Acrosome reaction rate (AR) was assessed by triple-stain.

RESULTSThe mean concentration of seminal plasma Ang II was 4 times as high as that of blood plasma in all patients and controls (P < 0.01), but there was no correlation between them. The seminal plasma Ang II of azoospermic patients was higher than that of other infertile men and controls(P < 0.05), but no difference was found between the latter two groups. There was no correlation between seminal plasma Ang II values and other traditional parameters of sperm together with AR.

CONCLUSIONSSeminal plasma Ang II may be secreted locally in male reproductive tract. In addition to testis and epididymis, prostate and/or seminal vesicle may also be the source of it. The reason why seminal plasma Ang II of azoospermic patients is higher than that of others remains unknown. Further study is required to clarify the exact role of seminal plasma Ang II in the mechanisms of male fertility regulation.

Acrosome ; physiology ; Adult ; Angiotensin II ; analysis ; blood ; physiology ; Chromatography, High Pressure Liquid ; Humans ; Infertility, Male ; etiology ; metabolism ; Male ; Radioimmunoassay ; Renin-Angiotensin System ; physiology ; Semen ; chemistry

Mechanisms of acupuncture and moxibustion for treatment of hypertension have been studied extensively from poly-aspects, poly-levels and poly-links. The present paper reviews the studies on nervous regulation, humoral regulation and regulation of peripheral vessel resistance and other pathways and their relationships in recent ten years, and indicates further perfecting these studies from the following aspects: studies on the mechanism of section and combination of blood pressure-decreasing points, relationship of time-effect and dose-effect of acupuncture and moxibustion, and studies on mechanisms of functions of nerve-endocrine-immune system.
Acupuncture Therapy ; Brain ; physiology ; Endothelins ; physiology ; Humans ; Hypertension ; physiopathology ; therapy ; Moxibustion ; Neurotransmitter Agents ; physiology ; Peripheral Nerves ; physiology ; Renin-Angiotensin System ; physiology ; Vascular Resistance

Animals ; Diet, Atherogenic ; Disease Models, Animal ; Heart ; physiopathology ; Myocardium ; pathology ; Obesity ; etiology ; physiopathology ; Rats ; Renin-Angiotensin System ; physiology

OBJECTIVETo investigate the changes of blood pressure by 24-hour ambulatory blood pressure (ABP) monitoring in children with primary nephrotic syndrome (PNS) and explore the relationship of the changes in blood pressure with rennin-angiotensin-aldosterone system (RAAS) in these children.

METHODSABP and casual blood pressure (CBP) monitoring were performed in 114 children with PNS. Plasma levels of rennin activity (PRA), angiotensin II (AngII) and aldosterone (ALD) were measured. The correlation of plasma levels of PRA, AngII and ALD with ABP was evaluated.

RESULTSOf the 114 children with PNS, 101 (88.6%) presented elevated blood pressure. Mild or severe masked hypertension was found in 45 children (39.5%). Eighty (70.2%) children showed non-dipper blood pressure. The index and load of systolic blood pressure were higher than those of diastolic blood pressure. The blood pressure index and blood pressure load during sleep were higher than those during wakefulness. The boy presented higher diastolic blood pressure index and load than girls. Decubitus blood PRA, AngII and ALD levels in children with PNS were significantly higher than normal controls. The group with elevated blood pressure presented significantly higher decubitus blood PRA, AngII and ALD levels than the group with normal blood pressure. AngII level was significantly positively correlated with the index and load of both systolic blood pressure and diastolic blood pressure.

CONCLUSIONSThe children with PNS present a high incidence of hypertension, with a large percentage of masked hypertension and non-dipper blood pressure. Systolic blood pressure increases more significantly than diastolic blood pressure. Blood pressure during sleep increases more significantly than that during wakefulness. Diastolic blood pressure increases more significantly in boys than in girls. RAAS activity is elevated and the elevated RAAS activity might increase the blood pressure mainly by AngII in children with PNS.

Adolescent ; Blood Pressure ; Blood Pressure Monitoring, Ambulatory ; Child ; Child, Preschool ; Female ; Humans ; Male ; Nephrotic Syndrome ; physiopathology ; Renin-Angiotensin System ; physiology