OBJECTIVEThis study was undertaken to observe the change in the local level of angiotensin II (Ang II) and the expression of its corresponding receptors AT1 and AT2 during wound healing, and explore the possible role of Ang II in wound healing .

METHODSA model of full-thickness cutaneous wound was developed on the back of C57/BL6 mice. Specimens were taken from the wound of each mouse on the day 0, 1, 3, 5, 7, 9, 11, 13 and 15 after wounding. The change in the generation of Ang II in wounded tissue during the healing process was detected with ELISA. The proliferation and the apoptosis of cells were detected by bromodeoxyuridine (Brdu) and terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling (TUNEL) method in wounded skin during the healing process, respectively. The cellular localization and the mRNA level change of Ang II receptors in wounded tissue during healing were detected with immunostaining and RT-PCR.

RESULTSAng II produced in wounded skin was increased in the first 7 days to reach the peak, and then gradually decreased during wound healing. BrdU labeling index was increased gradually in the first 7 days to reach the peak, and then gradually decreased during wound healing. The number of TUNEL-positive cells was increased slowly in the first 7 days after wounding. The increase in the number of TUNEL-positive cells was more markedly after epithelization of the wound. In normal mice, AT1 and AT2 receptor were found positively expressed in the whole epidermal layer, while positive expression was only found in the endothelial cells of the capillary vessels within the dermal layer, and positive expression was also found in appendages of the skin, i. e. hair follicle, sweat gland and sebaceous gland respectively. Positive staining signal of both AT1 and AT2 receptors were increased in the first 7 days to reach the peak, then gradually decreased. Expression of AT2R was increased again following the epithelization of wound. The result of RT-PCR showed that the expression of both AT1 and AT2 receptors was detectable, and AT1 receptor was increased in the first 7 days to the peak, and then gradually decreased during wound healing, while AT2 receptor expression reached its peak value on day 7, then gradually decreased, and increased again following the epithelization of wound.

CONCLUSIONSThese results indicate that Ang II participate in wound repair and related to remolding in the late stage of wound healing through the change in production of angiotensin II and expression of AT1 and AT2 receptors. AT1 receptor might be closely associated with cell proliferation, while AT2 receptor might play a role in cell apoptosis and remolding during wound healing.

Angiotensin II ; genetics ; metabolism ; Animals ; Apoptosis ; Cell Proliferation ; Male ; Mice ; Mice, Inbred C57BL ; RNA, Messenger ; genetics ; Receptors, Angiotensin ; genetics ; metabolism ; Skin ; injuries ; metabolism ; pathology ; Wound Healing ; physiology

OBJECTIVETo identify the A1166/C polymorphism of angiotensin II type 1 receptor (AT1R) gene in patients with essential hypertension complicated with brain infarction (BI).

METHODSAT1R genotyping with polymerase chain reaction-restrictive fragment length polymorphism was performed in 70 normotensive subjects, 72 hypertensive patients without cardio-cerebrovascular diseases(EH-NCCVD) and 70 hypertensive patients with BI. The relationship between the polymorphism of AT1R gene and plasma lipid levels was also studied.

RESULTSThe frequencies of C allele in the two groups of hypertension were higher than that in the health controls, respectively (P<0.05). But there was no significant difference in the frequency of C allele between the two groups of hypertension. A positive correlation was observed between the lipoprotein(a) and AT1R gene A1166/C polymorphism in hypertensive patients.

CONCLUSIONAT1R gene contributes to the development of essential hypertensive, but not to the incidence of BI in the hypertensive.

Aged ; Alleles ; Brain Infarction ; complications ; Female ; Gene Frequency ; Humans ; Hypertension ; blood ; complications ; genetics ; Lipids ; blood ; Male ; Middle Aged ; Polymorphism, Genetic ; Receptor, Angiotensin, Type 1 ; Receptors, Angiotensin ; genetics

Autosomal dominant polycystic kidney disease (ADPKD), a common genetic disease, is characterized by the development of hypertension and end stage renal disease. An increase in the activity of the renin-angiotensin system, due to a renal ischemia caused by cyst expansion, contributes to the development of hypertension and renal failure in ADPKD. Recently, the angiotensinogen (AGT) gene, M235T, and angiotensin II type 1 receptor (ATR) gene, A1166C, polymorphisms have been associated with the susceptibility to develop hypertension and renal disease. We hypothesized that the AGT M235T and ATR A1166C polymorphisms could account for some of the variability in the progression of ADPKD. Genotyping was performed in 108 adult patients with ADPKD, and 105 normotensive healthy controls, using PCR and restriction digestion. We analyzed the effects of the AGT M235T and ATR A1166C polymorphisms on hypertension and age at the end stage renal disease (ESRD). Of the 108 patients with ADPKD, 64 (59%) had hypertension and 24 (22%) reached the ESRD. The prevalence of hypertension were; [MM+MT], [TT] genotypes, 60%, 59% (p=1.00) ; [AA], [AC+CC] genotypes, 60%, 50% respectively (p=0.54). The ages at the onset of ESRD were; [MM+MT], [TT] genotypes, 50 +/- 9 years, 56 +/- 8 years (p=0.07) ; [AA], [AC+CC] genotypes, 54 +/- 8 years, 52 +/- 14 years, respectively (p=0.07). There were no differences in the prevalence of hypertension and the ages at the ESRD in relation to the AGT M235T and ATR A1166C polymorphisms. We suggest that the AGT and ATR gene polymorphisms would not have an effect on hypertension or the ESRD in ADPKD.
Adult ; Age of Onset ; Angiotensinogen/*genetics ; Disease Progression ; Female ; Human ; Hypertension/epidemiology/etiology ; Kidney Failure, Chronic/epidemiology/etiology ; Male ; Middle Aged ; Polycystic Kidney, Autosomal Dominant/complications/*genetics/physiopathology ; Polymorphism (Genetics) ; Prevalence ; Receptor, Angiotensin, Type 1 ; Receptors, Angiotensin/*genetics

OBJECTIVETo investigate the mechanism of a novel angiotensin II type 1 receptor-associated protein (ATRAP) interfering with angiotensin II type 1 (AT1) receptor-mediated vascular smooth muscle cell (VSMC) growth and neointimal formation.

METHODSVSMCs isolated from thoracic aorta of adult Sprague-Dawley (SD) rats were used in this study. ATRAP cDNA was subcloned into pcDNA3 vector and then transfected into VSMCs. DNA synthesis and extracellular signal-regulated kinase (ERK) and phospho-ERK expressions in VSMCs were assayed by measurement of 3H thymidine incorporation and Western blotting, respectively. Morphological changes were observed in the balloon injured artery with or without transfection of ATRAP cDNA using 12-week-old male SD rats.

RESULTSATRAP overexpression in VSMCs inhibited angiotensin II (Ang II)-induced 3H thymidine incorporation 48 hours after Ang II stimulation (P < 0.05). In VSMC, Ang II stimulation increased the phosphorylation of ERK, which reached the peak around 60 minutes. The activation of phospho-ERK was significantly decreased by ATRAP (P < 0.05). Neointimal formation was markedly inhibited by ATRAP overexpression in injuried arteries.

CONCLUSIONSThe AT1 receptor-derived activation of ERK plays an essential role in Ang II-induced VSMC growth. The growth inhibitory effects of ATRAP might be due to interfering with AT1 receptor-mediated activation of ERK in VSMC growth and neointimal formation.

Angiotensin II ; pharmacology ; Animals ; Aorta, Thoracic ; cytology ; Cell Division ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Male ; Muscle, Smooth, Vascular ; cytology ; physiology ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Receptor, Angiotensin, Type 1 ; physiology ; Receptors, Angiotensin ; genetics ; physiology ; Transfection ; Tunica Intima ; cytology

OBJECTIVETo explore the immuno-neurologic regulation of hypertension and its inherent law as well as the mechanisms of curing and systemic regulating effect of ZiShuiJiangHuoYin(ZSJHY).

METHODTo detect expression level of AT-1mRNA in two-kidney-one-clamp renal hypertension rat lymphocyte cell by means of RT-PCR.

RESULTThe level of AT-1 mRNA in lymphocyte was higher in group of 2K1C-RHR than that in normal group. ZSJHY (20 g/kg, 40 g/kg) had regulating effect on this.

CONCLUSIONDepressing excessive expression of lymphocyte AT-1 mRNA may be one of the mechanisms where ZSJHY exert immunoregulation action.

Animals ; Drug Combinations ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Hypertension, Renovascular ; metabolism ; Lymphocytes ; metabolism ; Male ; Plants, Medicinal ; chemistry ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; Receptors, Angiotensin ; biosynthesis ; genetics

BACKGROUNDMany studies have suggested that angiotensin II (Ang II) and its receptors may be involved in the development of asthma. However, the expression of angiotensin II receptors (AGTR) is not clear in the lung tissue of chronic asthmatics. This study was designed to determine the relationship between airway remodeling, dysfunction and the expression of AGTRs in a rat model of asthma.

METHODSRats were sensitized with ovalbumin (OVA) for 2 weeks. Sixty minutes before an inhalation challenge, the rats were pretreated either with valsartan (15, 30, 50 mg x kg(-1) x d(-1)) or saline intragastrically. Then the rats received an OVA challenge for 30 alternative days. Acetylcholine (Ach)-induced bronchoconstriction was measured after the final antigen challenge. White cell counts in bronchoalveolar lavage fluid (BALF) and morphological changes in the airways were then assessed. The levels of transforming growth factor-beta 1 (TGF-beta(1)) and platelet-derived growth factor (PDGF) in BALF were detected by ELISA. The levels of AGTR1 and AGTR2 mRNA and protein in lung tissues were measured by RT-PCR and Western blotting.

RESULTSAGTR1 mRNA and protein levels in repeatedly OVA-challenged rats were significantly increased as compared with negative controls. The AGTR1 mRNA expression versus white cell counts of BALF and airway wall thickness (mainly in small airways) in lungs of chronic antigen-exposed rats were positively correlated. Valsartan decreased the level of AGTR1 in repeatedly OVA-challenged rats. However, AGTR2 mRNA and protein levels in the OVA-challenged rats and high-dose valsartan-treated rats (50 mg x kg(-1) x d(-1)) were also increased. Valsartan significantly decreased inflammatory cell accumulation and attenuated Ach-evoked bronchoconstriction in repeatedly antigen-challenged rats. Valsartan also decreased allergen-induced structural changes in rat airway (including total airway wall thickness and smooth muscle area) and the levels of TGF-beta(1) and PDGF in BALF.

CONCLUSIONSAGTR1 expression is potentially associated with airway remodeling and dysfunction in asthma. Ang II and AGTR1 may participate in airway inflammation and airway remodeling of chronic antigen-exposed rats. Valsartan, a AGTR1 antagonist, could inhibit AGTR1 expression and partially inhibits structural airway changes as well as airway inflammation in chronic OVA-exposed rats.

Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Angiotensin Receptor Antagonists ; Animals ; Asthma ; chemically induced ; genetics ; metabolism ; Blotting, Western ; Bronchoalveolar Lavage Fluid ; chemistry ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; drug effects ; Lung ; drug effects ; metabolism ; pathology ; Male ; Ovalbumin ; Platelet-Derived Growth Factor ; metabolism ; Rats ; Rats, Wistar ; Receptor, Angiotensin, Type 1 ; genetics ; metabolism ; Receptor, Angiotensin, Type 2 ; genetics ; metabolism ; Receptors, Angiotensin ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tetrazoles ; pharmacology ; Transforming Growth Factor beta1 ; metabolism ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

Animals ; Hypertension ; metabolism ; physiopathology ; Male ; Myocardium ; metabolism ; Peptidyl-Dipeptidase A ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Receptor, Angiotensin, Type 1 ; genetics ; metabolism ; Receptors, G-Protein-Coupled ; genetics ; metabolism

Angiotensin II ; pharmacology ; Animals ; Cells, Cultured ; Cyclooxygenase 2 ; biosynthesis ; genetics ; Kupffer Cells ; cytology ; metabolism ; NF-kappa B ; metabolism ; Platelet-Derived Growth Factor ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-sis ; Rats ; Rats, Wistar ; Receptors, Angiotensin ; biosynthesis ; genetics ; Transforming Growth Factor beta ; biosynthesis ; genetics

It has been proposed that the local renin-angiotensin system is activated in the adventitia after vascular injury. However, the physiological role of Angiotensin II (Ang II) in the adventitia has not been studied at a cellular level. This study was designed to assess the role of Ang II in the growth response of cultured adventitial fibroblasts (AFs). Adventitial explants of the rat thoracic aorta showed outgrowth of AFs within 5-7 days. Ang II caused hyperplastic response of AF cultures. The Ang II-induced mitogenic response of AFs was mediated primarily by the AT1 receptor. Ang II caused a rapid induction of immediate early genes (c-fos, c-myc and jun B). Induction of c-fos expression was fully blocked by an AT1 receptor antagonist but not by an AT2 receptor antagonist. Epidermal growth factor (EGF), platelet-derived growth factor-BB (PDGF-BB) and basic fibroblast growth factor (bFGF) induced DNA synthesis in AFs. Co-stimulation of AFs with the growth factors and Ang II potentiated the incorporation of 3H-thymidine into DNA. Results from this study indicate that Ang II causes mitogenesis of AFs via AT1 receptor stimulation and potentiates the responses to other mitogens. These data suggest that the Ang II may play an important role in regulating AF function during vascular remodeling following arterial injury.
Angiotensin II/metabolism* ; Animal ; Aorta/pathology ; Blotting, Northern ; Cell Division ; Cells, Cultured ; DNA/biosynthesis ; Fibroblasts/pathology ; Fibroblasts/metabolism* ; Gene Expression/physiology ; Genes, Immediate-Early/genetics ; Growth Substances/metabolism* ; Hyperplasia/metabolism ; Losartan/pharmacology ; Male ; Proto-Oncogenes/genetics ; RNA/biosynthesis ; Rats ; Rats, Sprague-Dawley ; Receptors, Angiotensin/antagonists & inhibitors

OBJECTIVETo investigate the effect of losartan on cardiac mineralocorticoid receptor (MR) mRNA in rats after acute myocardial infarction (AMI).

METHODAMI was induced in male SD rats by ligation of the left coronary artery. The survived rats were randomly divided into AMI group, losartan group, and sham-operated group. The cardiac functions of the rats were assessed by echocardiogram and hemodynamics, and the contents of angiotensin II (Ang II) and aldosterone (Ald) in the myocardial tissues were determined by radioimmunoassay. The collagen density in the myocardial tissues were calculated by Masson's trichrome staining and the expression of MR mRNA were determined by real-time quantitative fluorescent PCR.

RESULTSBoth the contents of AngII and Ald in the myocardial tissues increased significantly in AMI group compared with those in the sham-operated group (P<0.01). The expression of MR mRNA and collagen density in the myocardial tissues also increased significantly than that in sham-operated group (P<0.01). After four weeks of losartan treatment, the contents of AngII and Ald in the myocardial tissues decreased significantly (P<0.05) and the expression of MR mRNA was also considerably lowered (P<0.01) in comparison with those in the AMI group. Treatment with losartan also resulted in significant decrease of the collagen density in the myocardial tissues.

CONCLUSIONSLosartan may reduce reactive fibrosis not only by attenuating the Ald signaling pathway but also by decreasing the expression of MR.

Aldosterone ; metabolism ; Angiotensin II ; metabolism ; Angiotensin II Type 1 Receptor Blockers ; therapeutic use ; Animals ; Fibrosis ; etiology ; prevention & control ; Losartan ; therapeutic use ; Male ; Myocardial Infarction ; drug therapy ; metabolism ; Myocardium ; pathology ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Mineralocorticoid ; genetics ; metabolism