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Effects of benazepril and losartan on proliferation and collagen synthesis of cultured cardiac fibroblasts from SHR
152A
POSTERS: Renin-Angiotensin-Aldosterone
AJH–April 2001–VOL. 14, NO. 4, PART 2
primary signaling event responsible for STAT mediated stimulation of the RAS.
both CFbSHR and CFbwky was promoted by Ang II and inhibited by Bena and Losartan.
Key Words: Renin-angiotensin, Janus kinase/STAT(s), gene regulation
Key Words: Cardiac fibroblasts, Benazepril, Losartan
P-363 AUTOMATED MEASUREMENT OF ACTIVE RENIN ON THE NICHOLS ADVANTAGE®CHEMILUMINESCENCE SYSTEM Shelby J. Hall, Elizabeth Gonzalez, Azita Mokhtari, Vijay Desai, Subramaniam Sundaram. 1Nichols Institute Diagnostics, San Juan Capistrano, CA, United States We have developed an automated chemiluminescent immunoassay for quantitating renin in plasma specimens, to be performed on the Nichols Advantage® Specialty System. This assay measures renin directly, is easier to standardize against the WHO reference material (from kidney), and is less labor-intensive than the classical enzyme kinetic PRA and PRC assays. Since the non-proteolytic activation of prorenin is time and temperature dependent, we attempted to minimize this activation by shortening the incubation time (30 min) and raising the incubation temperature to 37°C. Blood samples from normal subjects were obtained during standardized upright and supine positions, and the samples were processed at room temperature to avoid cryoactivation. Results indicate that the renin levels were significantly lower in supine than upright condition. This assay measures renin from 2 to 500 U/mL with an analytical sensitivity of 1 U/mL. The assay has no high dose hook for specimens with renin concentrations up to 100,000 U/mL. Recovery values obtained by serial dilution of EDTA plasma samples were between 87 - 100% across PRA concentrations of 5 - 57 ng/mL/hr. Intraassay variation of ⬎3 U/mL is 5%, and inter-assay variation at ⬎3 U/mL is ⬍10%. Direct comparison of results was made with a validated plasma renin activity (PRA) assay on n⫽68 patient samples. Range of results was 0.2 - 327 U/mL for the Nichols Advantage Active Renin assay and 0.3 - 57.7 ng/mL/hr for the PRA assay. Results of linear regression analysis show a correlation coefficient ’r’ ⫽ 0.97. The Nichols Advantage Active Renin assay is simple and rapid demonstrating good performance over a wide dynamic range. Key Words: Active Renin, Chemiluminescence, Automated
P-364 EFFECTS OF BENAZEPRIL AND LOSARTAN ON PROLIFERATION AND COLLAGEN SYNTHESIS OF CULTURED CARDIAC FIBROBLASTS FROM SHR Xie Liangdi, Chen Shuilong, Wu Kegui. 1Hypertension Division, The First Affiliated Hospital of Fujian Medical College, Fuzhou, China This study was to investigate the effects of angiotensin II (AngII), Benazepril (Bena) and Losartan on cell proliferation and collagen synthesis in cardiac fibroblasts (CFb). CFb derived from 12 wks old SHR (CFb SHR) and WKY (CFbWKY) were cultured by outgrowth of tissue block. Proliferation of CFb was measured by direct cell counting. Collagen synthesis was determined by 3H-proline incorporation. Data expressed as mean⫾SD of 5 determinations performed in triplicate. It was showed that in serum free (0.4% FCS) medium, Cell number of CFbSHR and CFbWKY was not significantly affected by AngII (10-10-10-6M) and Bena (10-9-10-5M). Increased 3H-proline incorporation of CFbSHR and CFbWKY was induced in a concentration dependent manner by Ang II (10-10-10-6M) in the presence of 0.4% FCS. The basal 3H-proline incorporation was 162% higher in CFbSHR than in CFbWKY(P⬍0.01). The increase in 3H-proline incorporation of CFbSHR and CFbWKY was 185% and 168% (P⬍0.01, respectively) in the medium containing 10-7 Ang II. 3 H-proline incorporation of CFbSHR and CFbWKY induced by 10-7 Ang II in the presence of 0.4% FCS was inhibited by both Bena and Losartan in a dose dependent manner. It was suggested that collagen synthesis of
P-365 ADAPTATION TO POTASSIUM RESTRICTION: HEART AND KIDNEY HYPERTROPHY, HYPOTENSION AND TISSUE-SPECIFIC CHANGES IN ACE EXPRESSION S. M. Danilov, I. V. Balyasnikova, R. F. Albrecht II, D. J. Visintine, R. Metzger, M. Garcia-Amaro, J. Feld, D. J. Miletich. 1Department of Anesthesilogy, Univ. of Illinois, Chicago, IL, United States Changes in dietary preferences from high K⫹/low Na⫹ consumption to the opposite appears to be the risk factor for cardiovascular diseases in industrial societies. The aim of this study is to characterize the effect of mild K⫹ restriction, in combination with high Na⫹ intake, on morphometric parameters, blood pressure, and ACE expression in the rat organs. Male SpragueDawley rats were fed for 6-12 weeks with four graded (50%, 37.5%, 25% and ⬍1% of daily req”s) K⫹ deficient diet with normal or high (12X) Na⫹. Morphometry, blood electrolytes, hematocrits, plasma volume and blood pressure measurements were determined weekly. ACE expression was measured enzymatically, by ACE immunoassay and by immunomorphological techinques. Potassium restriction results to heart and kidney hypertrophy, which accompanied by increasing of ACE expression in these organs. Extent of the hypertrophy, as well as ACE overexpression, directly correlated with extent of K⫹ deficiency. Combination of low K⫹ diet with high Na⫹ dramatically increased heart and kidney lesions. K⫹ deficiency alone leads to significant hypotension (92 ⫾ 2 mm Hg versus 118 ⫾ 3 in control) only at very severe restriction (⬍1% of daily req’s), whereas combination of high Na⫹ intake with even mild K⫹ restriction (25%-37.5 % of daily req’s) developed significant hypotension (100⫹2 and 106⫹3, respectively). ACE expression in lung and mesentery increased only at severe K⫹ deprivation (⬍1% of daily req’s) in combination with high Na⫹ intake, whereas intermediate K⫹ restriction lead to decreasing of ACE expression in the lung and consequent decreasing of ACE level in plasma. Dramatic hypertrophy in the heart and kidney. ACE overexpression in these organs, and significant hypotensive effect of K⫹ restriction might have clinical significance with regard to treatment by ACE inhibitors and All receptor antagonists. Grant/Research Support- Astra Zeneca Key Words: angiotensin-converting enzyme, hypertrophy, Potassium Restriction
P-366 EFFECT OF INTRARENAL INFUSION OF ANGIOTENSIN (1-7) IN THE DOG J. Heller, H. J. Kramer, J. Maly, L. Cervenka, V. Horacek. 1Dept. Exp. Med.,, IKEM, Prague, Czech Republic, 2Renal Section, Medical Policlinic, Univ. of Bonn, Germany Angiotensin (1-7), a metabolite of All and/or Al was infused into the renal artery (I.r.a.) of anesthetized dogs in order to investigate its renal action. Renal blood flow (RBF) was measured by electromagnetic flowmeter, glomerular filtration rate (GFR) by creatinine clearance. In group 1 animals A (1-7) at a dose of 15 /min/kg body weight did not affect systemic arterial blood pressure (BP) or water and sodium excretion from the contralateral non-infused kidney. Group 2 animals received EXP
POSTERS: Renin-Angiotensin-Aldosterone
AJH–April 2001–VOL. 14, NO. 4, PART 2
primary signaling event responsible for STAT mediated stimulation of the RAS.
both CFbSHR and CFbwky was promoted by Ang II and inhibited by Bena and Losartan.
Key Words: Renin-angiotensin, Janus kinase/STAT(s), gene regulation
Key Words: Cardiac fibroblasts, Benazepril, Losartan
P-363 AUTOMATED MEASUREMENT OF ACTIVE RENIN ON THE NICHOLS ADVANTAGE®CHEMILUMINESCENCE SYSTEM Shelby J. Hall, Elizabeth Gonzalez, Azita Mokhtari, Vijay Desai, Subramaniam Sundaram. 1Nichols Institute Diagnostics, San Juan Capistrano, CA, United States We have developed an automated chemiluminescent immunoassay for quantitating renin in plasma specimens, to be performed on the Nichols Advantage® Specialty System. This assay measures renin directly, is easier to standardize against the WHO reference material (from kidney), and is less labor-intensive than the classical enzyme kinetic PRA and PRC assays. Since the non-proteolytic activation of prorenin is time and temperature dependent, we attempted to minimize this activation by shortening the incubation time (30 min) and raising the incubation temperature to 37°C. Blood samples from normal subjects were obtained during standardized upright and supine positions, and the samples were processed at room temperature to avoid cryoactivation. Results indicate that the renin levels were significantly lower in supine than upright condition. This assay measures renin from 2 to 500 U/mL with an analytical sensitivity of 1 U/mL. The assay has no high dose hook for specimens with renin concentrations up to 100,000 U/mL. Recovery values obtained by serial dilution of EDTA plasma samples were between 87 - 100% across PRA concentrations of 5 - 57 ng/mL/hr. Intraassay variation of ⬎3 U/mL is 5%, and inter-assay variation at ⬎3 U/mL is ⬍10%. Direct comparison of results was made with a validated plasma renin activity (PRA) assay on n⫽68 patient samples. Range of results was 0.2 - 327 U/mL for the Nichols Advantage Active Renin assay and 0.3 - 57.7 ng/mL/hr for the PRA assay. Results of linear regression analysis show a correlation coefficient ’r’ ⫽ 0.97. The Nichols Advantage Active Renin assay is simple and rapid demonstrating good performance over a wide dynamic range. Key Words: Active Renin, Chemiluminescence, Automated
P-364 EFFECTS OF BENAZEPRIL AND LOSARTAN ON PROLIFERATION AND COLLAGEN SYNTHESIS OF CULTURED CARDIAC FIBROBLASTS FROM SHR Xie Liangdi, Chen Shuilong, Wu Kegui. 1Hypertension Division, The First Affiliated Hospital of Fujian Medical College, Fuzhou, China This study was to investigate the effects of angiotensin II (AngII), Benazepril (Bena) and Losartan on cell proliferation and collagen synthesis in cardiac fibroblasts (CFb). CFb derived from 12 wks old SHR (CFb SHR) and WKY (CFbWKY) were cultured by outgrowth of tissue block. Proliferation of CFb was measured by direct cell counting. Collagen synthesis was determined by 3H-proline incorporation. Data expressed as mean⫾SD of 5 determinations performed in triplicate. It was showed that in serum free (0.4% FCS) medium, Cell number of CFbSHR and CFbWKY was not significantly affected by AngII (10-10-10-6M) and Bena (10-9-10-5M). Increased 3H-proline incorporation of CFbSHR and CFbWKY was induced in a concentration dependent manner by Ang II (10-10-10-6M) in the presence of 0.4% FCS. The basal 3H-proline incorporation was 162% higher in CFbSHR than in CFbWKY(P⬍0.01). The increase in 3H-proline incorporation of CFbSHR and CFbWKY was 185% and 168% (P⬍0.01, respectively) in the medium containing 10-7 Ang II. 3 H-proline incorporation of CFbSHR and CFbWKY induced by 10-7 Ang II in the presence of 0.4% FCS was inhibited by both Bena and Losartan in a dose dependent manner. It was suggested that collagen synthesis of
P-365 ADAPTATION TO POTASSIUM RESTRICTION: HEART AND KIDNEY HYPERTROPHY, HYPOTENSION AND TISSUE-SPECIFIC CHANGES IN ACE EXPRESSION S. M. Danilov, I. V. Balyasnikova, R. F. Albrecht II, D. J. Visintine, R. Metzger, M. Garcia-Amaro, J. Feld, D. J. Miletich. 1Department of Anesthesilogy, Univ. of Illinois, Chicago, IL, United States Changes in dietary preferences from high K⫹/low Na⫹ consumption to the opposite appears to be the risk factor for cardiovascular diseases in industrial societies. The aim of this study is to characterize the effect of mild K⫹ restriction, in combination with high Na⫹ intake, on morphometric parameters, blood pressure, and ACE expression in the rat organs. Male SpragueDawley rats were fed for 6-12 weeks with four graded (50%, 37.5%, 25% and ⬍1% of daily req”s) K⫹ deficient diet with normal or high (12X) Na⫹. Morphometry, blood electrolytes, hematocrits, plasma volume and blood pressure measurements were determined weekly. ACE expression was measured enzymatically, by ACE immunoassay and by immunomorphological techinques. Potassium restriction results to heart and kidney hypertrophy, which accompanied by increasing of ACE expression in these organs. Extent of the hypertrophy, as well as ACE overexpression, directly correlated with extent of K⫹ deficiency. Combination of low K⫹ diet with high Na⫹ dramatically increased heart and kidney lesions. K⫹ deficiency alone leads to significant hypotension (92 ⫾ 2 mm Hg versus 118 ⫾ 3 in control) only at very severe restriction (⬍1% of daily req’s), whereas combination of high Na⫹ intake with even mild K⫹ restriction (25%-37.5 % of daily req’s) developed significant hypotension (100⫹2 and 106⫹3, respectively). ACE expression in lung and mesentery increased only at severe K⫹ deprivation (⬍1% of daily req’s) in combination with high Na⫹ intake, whereas intermediate K⫹ restriction lead to decreasing of ACE expression in the lung and consequent decreasing of ACE level in plasma. Dramatic hypertrophy in the heart and kidney. ACE overexpression in these organs, and significant hypotensive effect of K⫹ restriction might have clinical significance with regard to treatment by ACE inhibitors and All receptor antagonists. Grant/Research Support- Astra Zeneca Key Words: angiotensin-converting enzyme, hypertrophy, Potassium Restriction
P-366 EFFECT OF INTRARENAL INFUSION OF ANGIOTENSIN (1-7) IN THE DOG J. Heller, H. J. Kramer, J. Maly, L. Cervenka, V. Horacek. 1Dept. Exp. Med.,, IKEM, Prague, Czech Republic, 2Renal Section, Medical Policlinic, Univ. of Bonn, Germany Angiotensin (1-7), a metabolite of All and/or Al was infused into the renal artery (I.r.a.) of anesthetized dogs in order to investigate its renal action. Renal blood flow (RBF) was measured by electromagnetic flowmeter, glomerular filtration rate (GFR) by creatinine clearance. In group 1 animals A (1-7) at a dose of 15 /min/kg body weight did not affect systemic arterial blood pressure (BP) or water and sodium excretion from the contralateral non-infused kidney. Group 2 animals received EXP