The present study was aimed at investigating whether the calcium current in the vascular smooth muscle (VSM) cells is altered in renal hypertension. Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were made in Sprague-Dawley rats. Rats without clipping the renal artery or implanting DOCA were used as control for 2K1C and DOCA-salt hypertension, respectively. Four weeks after clipping, systolic blood pressure was significantly higher in 2K1C rats than in control (192+/-24 and 119+/-4 mmHg, respectively, n=16 each). DOCA-salt rats also showed a higher blood pressure (180+/-15 mmHg, n=18) compared with control (121+/-6 mmHg, n=14). VSM cells were enzymatically and mechanically isolated from basilar arteries. Single relaxed VSM cells measured 5 ~ 10 mum in width and 70 ~ 150 mum in length were obtained. VSM cells could not be differentiated in size and shape between hypertensive and normotensive rats under light microscopy. High-threshold (L-type) calciumcurrents were recorded using whole-cell patch clamp technique. The amplitude of the current recorded from VSM cells was larger in 2K1C hypertension than in control. Neither the voltage-dependence of the calcium current nor the cell capacitance was significantly affected by 2K1C hypertension. By contrast, the amplitude of the calcium current was not altered in DOCA-salt hypertension. These results suggest that high-threshold calcium current of the VSM cells is altered in 2K1C hypertension, and that calcium channel may not be involved in calcium recruitment of VSM in DOCA-salt hypertension.
Animals ; Basilar Artery ; Blood Pressure ; Calcium Channels ; Calcium* ; Desoxycorticosterone ; Desoxycorticosterone Acetate ; Hypertension ; Hypertension, Renal* ; Microscopy ; Muscle, Smooth, Vascular* ; Rats ; Rats, Sprague-Dawley ; Renal Artery

As a process to study the mechanism of steroid hormones at the molecular level,the activities of lactic dehydrogenase (L.D.) and malic dehydrogenase (M.D.),NAD-linked transhydrogenases, were measured in the testis and the prostate. Ahundred male rabbits were divided into ten group as follows: Group 1: Control Group 2: Estrogen (6,000 units) injected Group 3: Androgen (1,200 unite)injected Group 4: Progesterone (1,200 units) injected Group 5: Hydrocortisone(30 mg) injected Group 6: DOCA (6 mg) injected Group 7: Castration control Group8: Castration and estrogen (6, OOO units) injected Group 9: Castration and androgen (1,200 units) injected Group 10: Castration and progesterone (1,200units) injected Changes in the activities of lactic dehydrogenase and malic dehydrogenase in theorganic tissues by exogenous steroid hormones were carefullyobserved. The lactic dehydrogenase activities were measured by the method of Wroblewski and La Due, and malic dehydrogenase activities by the Bodansky's modification of Porter's method. The results are as follows: 1) The control valueof L.D. activities in the testicular tissue of normal rabbits proved to be 89,400units per ram. The L.D. activities showed an increase up to 110.4 per cent in theestrogen injected group, 179.3 per cent in the androgen injected group and 147.0 per cent in the progesterone injected group, while the administration of hydrocortisone and DOCA decreased the value down to 85.2 per cent and 81.5 per cent, respectively. 2) The control value of M.D. activities in the testicular tissue of the normal rabbits was 23,600 units per gram. The M.D. activities showed an increase upto 111.4 per cent in the estrogen injected group. 191.1 per cent in the androgen injected group, and 156.8 per cent in the progesterone injected group, while the administration of hydrocortisone and DOCA decreased the value down to 85.2 per cent and 81.5 per cent, respectively. 3) In the prostate tissues of non-castrated rabbits, the L.D. activities were estimated normally to be 48,100 units per gram. The administration of sex hormone resulted in raising the activities upto 101.8 per cent in the estrogen injected group, 196.9 per cent in the androgen injected group and 153.9 per cent in the progesterone injected group. But the administration of hydrocortisone and DOCA decreased the value down to 92.5 per cent and 97.1 per cent, respectively. 4) In the prostate tissue of non-castrated rabbits, the control value of M.D. activities proved to be 14,600 unite per gram. The M.D. activities showed an increase upto 117.8 per cent in the estrogen injected group, 206.8 per cent in the androgen injected group and, 176.7 per cent in the progesterone injected group, while the administration of hydrocortisone and DOCA decreased the value down to 81.9 per cent and 95.2 per cent, respectively. 5) The prostatic L.D. activities were decreased to half the normal two weeks after castration. The administration of sex hormones (i.e., estrogen, androgen and progesterone) acted inclusively upon elevating the level f activities. Androgen, in general, was the most effective to restore the activity to the level of pre-castrated state. 6) The prostatic M.D. activities were also decreased to half the normal two weeks after castration. The administration of sex hormones acted inclusively upon elevating the level ofthe activities. Androgen had a remarkable effect in elevating the M.D. activities, which showed twice the precastration level. In this study, it is concluded that L.D. and M.D. activities are present in the testis and the prostate. They are induced and activated by the administration of sex hormones, of which androgen has the most remarkable effect, and estrogen and progesteronehave less effect, while hydrocortisone and DOCA are ineffective in some cases orinhibitory in others.
Castration* ; Desoxycorticosterone Acetate ; Estrogens ; Gonadal Steroid Hormones ; Humans ; Hydrocortisone ; Malate Dehydrogenase* ; Male* ; Oxidoreductases ; Progesterone ; Prostate* ; Rabbits* ; Testis*

BACKGROUND: Effects of oxidative stress on the development of deoxycorticosterone acetate (DOCA)-salt or N(G)-nitro-L-arginine (L-NAME) hypertension were examined. METHODS: Male Sprague-awley rats were treated with DOCA (200 mg/kg, subcutaneous)-salt or L-NAME (40 mg/L in daily drinking water) for 4 weeks. To reduce the oxidative stress, 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol, 3 mM/L) was cotreated in drinking water. The expression of endothelial nitric oxide synthase (eNOS) and nitrotyrosine proteins was determined in the renal cortex and thoracic aorta. RESULTS: Tempol prevented the development of DOCA-salt hypertension, whereas it was without effect on L-NAME hypertension. In DOCA-salt hypertension, the eNOS expression in the renal cortex was increased, the degree of which was attenuated by Tempol. The renal expression of nitrotyrosine was decreased, which was further decreased by Tempol. In the aorta, the expression of both eNOS and nitrotyrosine was decreased, which was not further affected by Tempol. In L-NAME hypertension, the renal expression of eNOS was significantly increased, which was blocked by Tempol. The expression of eNOS in the aorta was slightly decreased, and was not further affected by Tempol. The renal expression of nitrotyrosine was not significantly altered. However, its expression was significantly decreased in the aorta, and was further reduced by Tempol. CONCLUSION: The blockade of oxidative stress may attenuate the development of hypertension and provide tissue protection in DOCA-salt hypertension. The blockade of oxidative stress may also contribute to a tissue protection in L-NAME hypertension.
Animals ; Aorta ; Aorta, Thoracic ; Blood Pressure* ; Desoxycorticosterone ; Desoxycorticosterone Acetate ; Drinking ; Drinking Water ; Humans ; Hypertension* ; Male ; NG-Nitroarginine Methyl Ester ; Nitric Oxide Synthase ; Nitric Oxide Synthase Type III ; Oxidative Stress* ; Rats

It has been known that activation of tyrosine kinases is involved in signal transduction. Role of the tyrosine kinase in vascular smooth muscle contraction was examined in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Male Sprague-Dawley rats underwent uninephrectomy, one week after which they were subcutaneously implanted with DOCA (200 mg/kg) and supplied with 1% NaCl and 0.2% KCl drinking water for 4-6 weeks. Control rats were treated the same except for that no DOCA was implanted. Helical strips of carotid arteries were mounted in organ baths for measurement of isometric force development. Genistein was used as a tyrosine kinase inhibitor. Concentration-response curves to 5-hydroxytryptamine (5-HT) shifted to the right by genistein in both DOCA-salt hypertensive and control rats. Although the sensitivity to genistein was similar between the two groups, the maximum force generation by 5-HT was less inhibited by genistein in arteries from DOCA-salt hypertensive rats than in those from controls. Genistein-induced relaxations were attenuated in arteries from DOCA-salt rats. Genistein affected the contraction to phorbol 12, 13-dibutyrate (PDBu) neither in DOCA-salt nor in control arteries. These observations suggest that tyrosine kinase is involved in 5-HT-induced vascular contraction, of which role is reduced in DOCA-salt hypertension.
Animals ; Arteries ; Baths ; Carotid Arteries ; Desoxycorticosterone Acetate ; Desoxycorticosterone* ; Drinking Water ; Genistein ; Humans ; Hypertension ; Male ; Muscle, Smooth, Vascular ; Phosphotransferases* ; Protein-Tyrosine Kinases ; Rats* ; Rats, Sprague-Dawley ; Relaxation ; Serotonin ; Signal Transduction ; Tyrosine*

Congenital adrenal hyperplasia is inherited disorder of adrenal steroidogenesis. 21-hydroxylase deficiency is the most commone enzymatic defect and is divided into classic and late-onset or nonclassic forms. Both classic non-classic 21-hydrozylase deficiencies are inherited in a recessive manner as allelic variants. But it is rare that happened in twin infants. Chief complaints of affected twins in our case were ambiguous genitalia, hyperpigmentation and dehydrations. They were revealed into hyponatremia, hyperkalemia and increased amount of serum progesterone, 17-hydroxyprogesterone and urinary 17-ketosteroid excretion and were administered with DOCA, 9alpha-fluorohydrocortisone, hydrocortisone to control the electrolyte imbalance. And now, both of them are going to normal ratio of weight gain and body growth.
17-alpha-Hydroxyprogesterone ; Adrenal Hyperplasia, Congenital* ; Desoxycorticosterone Acetate ; Disorders of Sex Development ; Humans ; Hydrocortisone ; Hyperkalemia ; Hyperpigmentation ; Hyponatremia ; Infant ; Progesterone ; Steroid 21-Hydroxylase* ; Twins* ; Weight Gain

BACKGROUND: The present study was designed to evaluate the possible renoprotective effects of tamoxifen in deoxycorticosterone acetate (DOCA)-salt hypertensive (DSH) rats and its role in inflammation and fibrosis in the kidney. METHODS: Male Sprague-Dawley rats, weighing 180 to 200 g, were used. All rats underwent unilateral nephrectomy. One week later, one group of rats (n = 8) was implanted with DOCA strips (200 mg/kg) and another group of rats (n = 8) was implanted with DOCA strips with co-treated with tamoxifen (10 mg/kg) through gavage feeding. Rats that did not implanted DOCA strips served as controls (n = 6). Two weeks later, the systolic blood pressure (SBP) was measured by tail-cuff method. The protein expression of transforming growth factor-beta (TGF-beta), Smad, alpha-smooth muscle actin (alpha-SMA), E-cadherin, ED-1, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) was determined in the kidney by immunoblotting. The mRNA expression of tumor necrosis factor-alpha (TNF-alpha), monocyte chemotactic protein-1 (MCP-1), and vascular cell adhesion molecule-1 (VCAM-1) was determined by real-time polymerase chain reaction. RESULTS: In DSH rats, SBP was increased, which was not affected by tamoxifen treatment. Serum creatinine level was comparable in DSH rats compared with controls, which was not affected by tamoxifen treatment. In DSH rats, the protein expression of TGF-beta, Smad 2/3, Smad 4, alpha-SMA, ED-1, COX-2, iNOS was increased compared with controls, and these changes were attenuated by tamoxifen treatment except that of TGF-beta. The mRNA expression of TNF-alpha, MCP-1, and VCAM-1 was increased, and expression of MCP-1 and VCAM-1 was counteracted by tamoxifen treatment. CONCLUSIONS: Tamoxifen is effective in preventing the progression of nephropathy in DSH rats, the mechanism of which is associated with anti-inflammation and anti-fibrotic effects.
Actins ; Animals ; Blood Pressure ; Cadherins ; Chemokine CCL2 ; Creatinine ; Cyclooxygenase 2 ; Desoxycorticosterone Acetate ; Desoxycorticosterone* ; Fibrosis ; Humans ; Hypertension ; Immunoblotting ; Inflammation ; Kidney ; Male ; Methods ; Muscles ; Nephrectomy ; Nitric Oxide Synthase Type II ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Tamoxifen* ; Transforming Growth Factor beta ; Tumor Necrosis Factor-alpha ; Vascular Cell Adhesion Molecule-1

OBJECTIVETo investigate whether brain reactive oxygen species mediate sympathoexcitation and arterial pressure elevation in DOCA-salt hypertensive rats.

METHODSDOCA-salt hypertensive model was established in male SD rats by subcutaneous injection of DOCA after uninephrectomy and drinking 1% NaCl solution for 4 weeks. The baseline mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were recorded in the rats under mild anesthesia, and MAP changes following intravenous hexamethonium injection were observed. The responses of MAP, HR and RSNA to intracerebroventricular administration of tempol (20 µmol/L in 10 µl) were evaluated; plasma NE level was measured with ELISA, and ROS level and NAD(P)H oxidase activity in the hypothalamus were detected using chemiluminescence assay.

RESULTSMAP and plasma NE levels were significantly increased in DOCA-salt rats as compared with those in the control group (P<0.01). In DOCA-salt hypertensive rats, intravenous hexamethonium injection induced a blood pressure reduction 240% of that in control rats, and significantly increased the levels of superoxide anion and NAD(P)H oxidase activity in the hypothalamus. Intracerebroventricular microinjection of tempol also resulted in more significant changes of MAP, HR and RSNA in DOCA-salt rats than in the control group (P<0.01).

CONCLUSIONSympathoexcitation due to increased NAD(P)H oxidase-derived ROS levels in the hypothalamus may mediate arterial pressure elevation in DOCA-salt hypertensive rats.

Animals ; Antioxidants ; Arterial Pressure ; Blood Pressure ; Brain ; metabolism ; Cyclic N-Oxides ; pharmacology ; Desoxycorticosterone ; Desoxycorticosterone Acetate ; Disease Models, Animal ; Heart Rate ; Hypertension ; Kidney ; innervation ; Male ; NADPH Oxidases ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Sodium Chloride ; Spin Labels ; Superoxides ; metabolism ; Sympathetic Nervous System

CG200745 is a novel inhibitor of histone deacetylases (HDACs), initially developed for treatment of various hematological and solid cancers. Because it is water-soluble, it can be administered orally. We hypothesized that the HDAC inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in deoxycorticosterone acetate (DOCA)-induced hypertensive rats. For establishment of hypertension, 40 mg/kg of DOCA was subcutaneously injected four times weekly into Sprague-Dawley rats. All the rats used in this study including those in the sham group had been unilaterally nephrectomized and allowed free access to drinking water containing 1% NaCl. Systolic blood pressure was measured by the tail-cuff method. Blood chemistry including sodium, potassium, glucose, triglyceride, and cholesterol levels was analyzed. Sections of the heart were visualized after trichrome and hematoxylin and eosin stain. The expression of hypertrophic genes such as atrial natriuretic peptide A (Nppa) and atrial natriuretic peptide B (Nppb) in addition to fibrotic genes such as Collagen-1, Collagen-3, connective tissue growth factor (Ctgf), and Fibronectin were measured by quantitative real-time PCR (qRT-PCR). Injection of DOCA increased systolic blood pressure, heart weight, and cardiac fibrosis, which was attenuated by CG200745. Neither DOCA nor CG200745 affected body weight, vascular contraction and relaxation responses, and blood chemistry. Injection of DOCA increased expression of both hypertrophic and fibrotic genes, which was abrogated by CG200745. These results indicate that CG200745 attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats.
Animals ; Blood Pressure ; Body Weight ; Cardiomegaly* ; Chemistry ; Cholesterol ; Connective Tissue Growth Factor ; Desoxycorticosterone ; Desoxycorticosterone Acetate ; Drinking Water ; Eosine Yellowish-(YS) ; Fibronectins ; Fibrosis* ; Glucose ; Heart ; Hematoxylin ; Histone Deacetylase Inhibitors* ; Histone Deacetylases* ; Histones* ; Hypertension ; Methods ; Potassium ; Rats* ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Relaxation ; Sodium ; Triglycerides

Pathophysiological implications of the vascular nitric oxide (NO)/cGMP pathway in hypertension were investigated. Sprague-Dawley rats were made deoxycorticosterone acetate (DOCA)-salt hypertensive for six weeks. The protein expression of endothelial constitutive NO synthase (ecNOS) and the tissue content of NO were determined in the thoracic aorta. The protein expression and catalytic activity of soluble guanylyl cyclase (GC) were also determined. Systolic blood pressure measured on the day of experiment was significantly higher in the experimental group than in the control. The hypertension was associated with decreases in the vascular tissue content of NO metabolites, concomitantly with the expression of ecNOS proteins. The protein expression of GC was not affected, while its catalytic activity was significantly decreased in hypertension. These results indicate that the high blood pressure is associated with a decreased activity of vascular NO/cGMP pathway in DOCA-salt hypertension.
Aorta, Thoracic ; Blood Pressure ; Desoxycorticosterone* ; Guanylate Cyclase* ; Hypertension* ; Nitric Oxide ; Nitric Oxide Synthase ; Rats, Sprague-Dawley

The present study was aimed at investigating whether the development of hypertension is related with an altered expression of nitric oxide synthases (NOS) in the kidney. By Western blot analysis, the expression of bNOS and ecNOS isoforms was determined in the kidney of deoxycorticosterone acetate (DOCA)-salt and two-kidney, one clip (2K1C) rats. In DOCA-salt hypertension, the expression of both bNOS and ecNOS was decreased, along with tissue contents of nitrites. In 2K1C hypertension, the nitrite content of the clipped kidney was decreased along with ecNOS levels, whereas neither the nitrite content nor the expression of NOS isoforms was significantly altered in the contralateral non-clipped kidney. These results suggest that the development of hypertension is associated with an altered renal expression of NOS and nitric oxide generation in DOCA-salt and 2K1C rats.
Animals ; Blotting, Western ; Desoxycorticosterone ; Hypertension ; Kidney ; Nitric Oxide* ; Nitrites ; Protein Isoforms ; Rats*