For studying the expression and distribution of angiotensinogen (AGT), the C-teminus of rat AGT gene was expressed in E.coli. Rabbits were immunized with expressed AGT protein and sera from different rabbits were raised. ELISA showed a high titre (1:25600) of the antiserum. With the antiserum, Western blotting recognized not only the prokaryotic expressed AGT, but also the endogenous AGT protein in liver tissue of both rats and humans. Using this antiserum, immunohistochemistry showed the expression of AGT protein in islet cells of human pancreas as well as in epithelium of human bile duct. These results suggest that the prokaryotic expressed AGT protein is an effective immunogen for the preparation of anti-AGT antiserum. Our present work provides an important tool for study of the pathophysiological role of AGT as well as local renin-angiotensin system.
Angiotensinogen ; genetics ; immunology ; Animals ; Antibodies, Monoclonal ; biosynthesis ; Escherichia coli ; genetics ; metabolism ; Humans ; Immune Sera ; biosynthesis ; immunology ; Immunization ; Rabbits ; Rats ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Renin-Angiotensin System ; physiology

OBJECTIVETo compare the mRNA expression of renin-angiotensin-aldosterone system in human subcutaneous and visceral adipose tissues.

METHODSTotal RNA was extracted from 12 human subcutaneous adipose tissues, 12 perirenal adipose tissue and 9 periadrenal adipose tissues. The expressions of angiotensinogen ( AGT) , renin, angiotensin converting enzyme ( ACE) , angiotensin converting enzyme 2 (ACE2), angiotensin I1 receptor type 1 (AT1), angiotensin II receptor type 2 (AT2 ), CYP11 B2, and their internal reference glyceraldehyde phosphate (GAPDH) were studied by reverse transcription-polymerase chain reaction. The ratios of each target genes were used to evaluate the expression levels of AGT, renin, ACE, ACE2, AT1, AT2, and CYP11B2 in different adipose tissues.

RESULTSThe mRNA expressions of AGT, ACE, ACE2, AT1, and AT2 were detected in human subcutaneous, perirenal, and periadrenal adipose tissues. However, CYPI B2 mRNA expression was not found in these three adipose tissues. The mRNA expressions of renin was only detected in perirenal and periadrenal adipose tissues, which was significantly higher in perirenal adipose tissues than in periadrenal adipose tissues ( P < 0. 05 ). The mRNA expressions of ACE and ACE2 in perirenal adipose tissues were significantly higher than that in subcutaneous adipose tissues ( P < 0. 05). The mRNA expressions of ACE were significantly higher than that of ACE2 in subcutaneous, perirenal, and periadrenal adipose tissues (P <0. 05). The mRNA expressions of AT1 were significantly lower than that of AT2 in periadrenal adipose tissues (P < 0. 05).

CONCLUSIONLocal renin-angiotensin system exists in the adipose tissues; however, aldosterone is not synthesized in the adipose tissues.

Adipose Tissue ; metabolism ; Adult ; Aged ; Aldosterone ; physiology ; Angiotensinogen ; biosynthesis ; Cytochrome P-450 CYP11B2 ; biosynthesis ; Female ; Humans ; Male ; Middle Aged ; Peptidyl-Dipeptidase A ; biosynthesis ; RNA, Messenger ; biosynthesis ; Receptor, Angiotensin, Type 1 ; biosynthesis ; Receptor, Angiotensin, Type 2 ; biosynthesis ; Renin ; biosynthesis ; Renin-Angiotensin System ; physiology ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo investigate the renin-angiotensin system (RAS) in mesenteric adipose tissues and effect of angiotensin II on adipocyte differentiation.

METHODSThirty normal 8-week-old male Wistar rats were divided into groups on normal diet and high-fat diet. The rats on high-fat diet for 24 weeks developed the metabolic syndrome respectively. The mRNA and protein expression of mesenteric adipose tissue were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Lipid drop in 3T3-L1 preadipocytes and mature adipocytes were observed using oil-red O staining. The fluorescence microscope was used to detect cytosolic-free calcium in 3T3-L1 preadipocytes and mature adipocytes.

RESULTSThe expressions of angiotensinogen, angiotensin converting enzyme, angiotensin II receptor type 1 in mesenteric adipose tissue were significantly increased in rats with metabolic syndrome compared with those in rats on normal diet (P <0. 05, P <0. 01). After administration of angiotensin II , no lipid droplet in 3T3 -L1 preadipocytes and adipocytes were observed, however, intensive lipid droplet in adipocyte was found after administration of captopril and candesartan. Angiotensin II increased the intracellular-free calcium concentration in preadipocytes (P < 0. 01 ) , which was blocked by captopril and candesartan; in contrast, angiotensin II effect was blunt in mature adipocyte. Captopril and candesartan partially recovered the angiotensin II -mediated increase of cytosolic-free calcium.

CONCLUSIONRAS in the mesenteric adipose tissues is active in rats with metabolic syndrome, and antagonization of RAS can recover the lipogenesis of adipocyte.

Adipocytes ; metabolism ; Adipose Tissue ; metabolism ; Angiotensin II ; pharmacology ; Angiotensinogen ; biosynthesis ; Animals ; Benzimidazoles ; pharmacology ; Calcium ; metabolism ; Captopril ; pharmacology ; Cells, Cultured ; Male ; Metabolic Syndrome ; physiopathology ; Peptidyl-Dipeptidase A ; biosynthesis ; RNA, Messenger ; biosynthesis ; Rats ; Rats, Wistar ; Receptor, Angiotensin, Type 2 ; biosynthesis ; Renin-Angiotensin System ; physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Tetrazoles ; pharmacology

The present study evaluated the importance of ovarian functions and the renin-angiotensin system in the progression of the right ventricular (RV) hypertrophy. Female Sprague-Dawley rats were bilaterally ovariectomized (Ovx) and injected with monocrotaline (MCT, 60 mg/kg, sc). Four weeks after MCT-treatment, only the male and Ovx female rats showed marked RV hypertrophy. The hypertrophied RV of the male-MCT and Ovx-MCT rats exhibited remarkably elevated renin mRNA levels. Gene expression levels of angiotensinogen, TGF-beta1, and endothelin-1 in the hypertrophied RV also increased, but to the less degree than did the renin mRNA. To investigate beneficial effects of estrogen or enalapril on progression of the pulmonary hypertension and RV hypertrophy, histological changes of the lung and heart were examined. Sham-MCT female rats showed histological changes indicating pulmonary hypertension without RV hypertrophy. In contrast, Ovx-MCT rats showed marked RV hypertrophy with pathological changes, denoting severe pulmonary and myocardial injuries. Estrogen-or enalapril-treated Ovx-MCT rats did not show RV hypertrophy, and showed remarkably ameliorated ultrastructural changes in the lung and RV. These results from this rat model suggest that both estrogen and inhibition of the renin-angiotensin system have protective functions against the development of the pulmonary hypertension and cardiac remodeling.
Angiotensin-Converting Enzyme Inhibitors/pharmacology ; Angiotensinogen/biosynthesis ; Animals ; Body Weight/drug effects ; Densitometry ; Disease Progression ; Enalapril/*pharmacology ; Endothelin-1/biosynthesis ; Estrogens/*pharmacology ; Female ; Hypertrophy, Right Ventricular/chemically induced/*drug therapy ; Male ; Microscopy, Electron ; Monocrotaline/*pharmacology ; Ovariectomy ; RNA/metabolism ; RNA, Messenger/metabolism ; Rats ; Rats, Sprague-Dawley ; Renin/biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Sex Factors ; Support, Non-U.S. Gov't ; Transforming Growth Factor beta/biosynthesis ; Ventricular Remodeling