Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study was designed to clarify the role of serum angiotensin I-converting enzyme (ACE) in the occurrence and maintenance of hypertension in essential hypertension (EH). For this purpose, following experiments were carried out: 1) Correlations between serum ACE activity and renin activity (PRA), aldosterone concentration (PAC) and bradykinin concentration (PBC) in plasma, and blood pressure (BP) as well as serum creatinine levels. 2) Circadian rhythm of serum ACE activity. and 3) Effect of furosemide, upright posture, both furosemide and upright posture, propranolol, indomethacin, 9 alpha-fluorocortisol or angiotensin II (A-II) on the serum ACE activity, PRA, PAC and circulating plasma volume (CPV). The following results were obtained: The serum ACE activity was 30.2 +/- 5.0 U/ml (means +/- SD) in EH as a group, which was significantly higher than that (27.3 +/- 3.9 U/ml) in age matched normotensive subjects (NT) (p less than 0.001). While there was no significant difference in the enzyme activity between low-renin EH (LREH) and NT, a significant difference was found between normal- (NREH) or high-renin EH (NREH) and NT (p less than 0.05 for NREH, p less than 0.01 for HREH). A negative correlation was observed between enzyme activity and age in EH (r = -0.221, 0.05 less than p less than 0.10) as well as in NT (r = -0.306, p less than 0.05). No significant relationships were observed between enzyme activity and BP in either EH or NT. There was a significant positive correlation between enzyme activity and PRA in NT. (r = 0.501, p less than 0.001), NREH (r = 0.658, p less than 0.001) and HREH (r = 0.695, p less than 0.001). However, no significant relationship was found between them in LREH. The enzyme activity was significantly correlated to PAC in NT (r = 0.368, p less than 0.01), NREH (r = 0.567, p less than 0.001) and HREH (r = 0.529, p less than 0.01), but not in LREH. Although no significant correlation was observed between enzyme activity and PBC in NT, NREH and HREH, a significant relationship was found in LREH (r = -0.460, 0.05 less than p less than 0.10). The enzyme activity was not related to serum creatinine levels in EH as well as in NT. In NT, the serum levels of ACE activity reached a maximum values at 6:00 a.m. or 9:00 a.m., and gradually decreased between 6:00 p.m. and 3:00 a.m. An almost similar circadian rhythm of enzyme activity was found in EH.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Clinical significance of serum angiotensin I-converting enzyme in essential hypertension]. 300 63

In order to evaluate the effect of the angiotensin I-converting enzyme inhibitor, captopril, on lipid metabolism, we measured serum lipoperoxides concentration ( LPX ) as well as plasma levels of renin activity (PRA), aldosterone (PAC) and bradykinin ( PBK ) before and after captopril administration in 15 hypertensive patients. Captopril significantly lowered the LPX (p less than 0.05 by repeated measures ANOVA) from the control value of 3.25 +/- 1.16 (mean +/- S.D.) to 2.92 +/- 0.94, 2.83 +/- 1.10, and 2.89 +/- 1.31 nmol/ml 30, 60, and 120 min after the administration, respectively. A significant reduction of blood pressure (p less than 0.0001) and PAC (p less than 0.01) was observed following captopril administration, while PBK increased significantly (p less than 0.001) from a baseline level of 10.85 +/- 4.07 to 13.95 +/- 5.29, 16.25 +/- 6.85, and 15.71 +/- 7.65 pg/ml 30, 60, and 120 min after captopril administration, respectively. There was no significant correlation between changes in serum LPX and in mean blood pressure, PRA and PAC, though a significant inverse relationship was found between changes in serum LPX and in PBK 120 min after the administration (r = -0.576, p less than 0.05, n = 13). Although the mechanisms by which serum LPX is decreased by captopril are not clear, it is suggested from the results that captopril is a beneficial antihypertensive agent for preventing LPX -induced atherosclerosis in hypertensive patients.
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PMID:[The effects of the angiotensin I-converting enzyme inhibitor, captopril, on serum lipoperoxides level and the renin-angiotensin-aldosterone and kallikrein-kinin systems in hypertensive patients]. 637 99

The existence of an interaction between bradykinin (Bk) receptors and the alpha 2-adrenoceptors were evaluated by means of quantitative receptor autoradiography in the nucleus tractus solitarii (NTS) of the rat. In competition experiments using L-noradrenaline (0.1 nM to 10 microM) against [3H]p-aminoclonidine ([3H]PAC) (10 nM) it was observed that Bk produced an increase in the IC50 value of L-noradrenaline in a concentration response manner, which reached a maximum of about 100% with 10 nM of the peptide associated with a small decrease in the B0 value (15%). In saturation experiments Bk promoted a significant increase in the KD value of [3H]PAC (60%) and a decrease in the Bmax value (36%). The specific Bk B2 receptor antagonist HOE-140 fully counteracted the effect of Bk on the alpha 2-adrenoceptors as analyzed by the competition experiments. Furthermore, des-Arg9-Bk, a Bk analog which exhibits selective agonist activity to the Bk B1 receptor subtype did not produce any effect on the alpha 2-adrenoceptors, suggesting that the Bk B2 receptor subtype may be mediating the Bk action on the alpha 2-adrenoceptors in the NTS. The effect of Bk (10 nM) was analyzed together with GTP (0.1 nM) in competition experiments and no change in the ability of L-noradrenaline to compete for [3H]PAC binding sites was observed in the presence of GTP, suggesting that the receptor interaction between the Bk B2 receptors and the alpha 2-adrenoceptors may be a G-protein dependent mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bradykinin modulation of alpha 2-adrenoceptors in the nucleus tractus solitarii of the rat. An in vitro autoradiographical study. 762 66

We describe a simple method for obtaining functionally and morphologically intact primary cultures of cells from the medullary thick ascending limb of rabbit kidneys. After digesting dissected fragments of the inner stripe of the outer medulla with collagenase, a suspension of tubule fragments is obtained, the vast majority of which are medullary thick ascending limb (MTAL) segments. These are identified individually by their morphological appearance and large amounts are collected with a micropipette mounted on a micromanipulator. This ensures maximal homogeneity of the starting material. Monolayers of cells grow out of these MTAL segments after seeding them onto collagen-coated, permeable filter supports. During the week following confluence, the cultures exhibit an apical side-positive transepithelial potential difference. Electron microscopic examination shows a monolayer of polarised cells with characteristics of distal tubular cells. The primary cultures express Tamm-Horsfall protein at their apical surface. Additional evidence for their differentiation and polarisation is the net ammonium influx, which occurs at very high rates across the apical membrane and is much slower across the basolateral membrane, as judged by measurements of intracellular pH. Adenosine 3',5'-cyclic monophosphate (cAMP) production is stimulated by arginine-vasopressin, calcitonin or isoproterenol (all 1 micromol/l). Intracellular calcium signalling is observed after stimulation with 1 micromol/l adenosine, adenosine 5'-triphosphate (ATP) and bradykinin. In addition, we compared these characteristics with those of TALH-SVE cell monolayers, an established immortalised cell line of the same origin.
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PMID:A simple method for obtaining functionally and morphologically intact primary cultures of the medullary thick ascending limb of Henle's loop (MTAL) from rabbit kidneys. 1095 49