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ABSTRACT: Urinary kallikrein excretion (UKE) was investigated in neurogenic hypertensive dogs for a period of 8 months. The animals were made hypertensive by sinoaortic denervation (SAD). Plasma catecholamine levels (PC), plasma renin activity (PRA), plasma aldosterone concentration (PAC) and urinary sodium excretion (UNa) were also measured. The onset of hypertension was associated with an increase in PC. UKE, measured by amidolytic and kininogenase activities, exhibited a very significant transient increase two and four weeks after SAD. Progressively, UKE significantly decreased below control values at the 16th and 32nd week. Since the month following SAD is characterized by an increase in sympathetic tone (as shown by high PC levels), the transient increase of UKE can be related to this high PC level; although this hypothesis is only supported by a positive relationship between these two parameters. The subsequent decrease in UKE appeared linked to diminished mineralocorticoid activity. Thus, the biphasic pattern of UKE observed in the study suggests that variations of UKE are more a consequence of hypertension than a pathogenic factor. Because UKE, which is of renal origin, is reduced at the end of the study period, this may also suggest possible renal dysfunctions in this model of hypertension.
Clinical and experimental hypertension. Part A, Theory and practice 02/1989; 11(2):215-31.
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ABSTRACT: Incubation of a radiolabeled bradykinin analog, [125I]-Tyr8-BK with a crude membrane preparation obtained from isolated rat glomeruli revealed a time dependent binding. The binding was saturable, reversible and was a linear function of protein membrane concentration. The radiolabeled Tyr8-BK bound to a single class of binding sites with an equilibrium dissociation constant (KD) of 3.9 +/_ 0.7 nM and a density (Bmax) of 31 +/- 5 fmol/mg protein. The BK-receptor complex was not affected by angiotensin II or by arginine vasopressin and atrial natriuretic factor. BK binding was reversed by bradykinin (Ki = 0.3 10(-9) M), and by other kinin analogs in the following order of potency: Lys-BK, Met-Lys-BK, Thi5,8-D Phe7-BK. However, Des-Arg9-BK had no effect on binding of the radiolabelled BK. These results are consistent with the presence of a B2-kinin like receptor in rat glomeruli.
Biochemical and Biophysical Research Communications 02/1989; 158(1):99-104. · 2.48 Impact Factor
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ABSTRACT: We have developed a sensitive and specific radioimmunoassay which allows the detection of human glandular kallikrein in biologic fluids at a level of 40 pg/ml. The antisera did not recognize human plasma kallikrein and glandular kallikrein from other species including marmoset. Furthermore the antibody did not bind pro-kallikrein but was specific for the trypsin activated kallikrein. The antibody inhibited the kininogenase activity of standard kallikrein incubated with human kininogen. However active kallikrein inhibited by inhibitors bound at the active site is still detectable, indicating that the antibody is specific for the structure of the active form but not for the active site. In normotensive subjects, daily urinary kallikrein excretion increased with age until 30, then a decrease was observed. In renal transplanted recipients a progressive increase of the active form was found. A low concentration of immunoreactive active kallikrein was detected in lymphatic fluids of patients suffering from acute pancreatitis treated by lymphatic drainage; although this kallikrein is the active immunoreactive form, a very weak kininogenase activity was measured, suggesting a partial inhibition by anti-proteases. These data provide complementary evidence for the physiological and pathological role of glandular kallikrein.
Journal of immunoassay 02/1989; 10(2-3):221-36.
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Advances in experimental medicine and biology 02/1989; 247A:275-9. · 1.09 Impact Factor
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Advances in experimental medicine and biology 02/1989; 247B:437-42. · 1.09 Impact Factor
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ABSTRACT: The urinary excretion of alanine aminopeptidase (AAP), gamma-glutamyl transpeptidase (gamma-GT) and of N-acetyl-beta-D-glucosaminidase (NAG) was studies in normal and castrated rats receiving either testosterone for 5 post-operative weeks or no hormone. In castrated rats the urinary output of AAP and gamma-GT was significantly lower than in sham control or in castrated rats receiving testosterone. In addition, an excess of exogenously given testosterone had no effect on enzymuria of normal rats. The urinary excretion of NAG was influenced neither by castration nor by testosterone. These results suggest that endogenous testosterone is responsible for a permanent positive control on the urinary excretion of AAP and gamma-GT.
Enzyme 02/1989; 41(4):181-6.
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ABSTRACT: Large scale purification of human active urinary kallikrein is described. The final preparation was found homogeneous by means of SDS Page electrophoresis, amino acid composition and N-terminal analysis. The apparent molecular weight, determined on SDS Page electrophoresis, was 4.4 X 10(4). Comparative inhibition studies of the kininogenase and the amidase activities pointed out differences in the sensitivity of these two activities. Sodium inhibited amidase activity whereas kininogenase activity required the presence of this cation. In contrast, kininogenase activity was more sensitive to cadmium inhibition than amidase activity. Antibody against purified kallikrein did not completely inhibit amidase activity in crude urine. These discrepancies are consistent with the existence of several amidase activities in urine and also with possibly distinct catalytic sites on the same molecule, accordingly consideration of the methodology used appears very important when comparing results from different studies.
Preparative biochemistry 02/1989; 19(2):75-90.
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ABSTRACT: An antibody against rat kallikrein was produced in rabbits and its localization was studied in various organs of the rat to confirm its specificity. The distribution of immunoreactive kallikrein was studied in rat ureter by use of immunochemical techniques. Ureteral tissue was fixed in Zamboni's-glutaraldehyde fixative and immunostained with indirect immunofluorescence and the peroxidase-antiperoxidase (PAP) method for light and electron microscopy. Preabsorption of the primary polyclonal antiserum with purified rat urinary kallikrein and substitution with normal serum were used as controls. By light microscopy, kallikrein was localized in the lamina propria and in the adventitial connective tissue surrounding the entire ureter. Immunoelectron microscopy confirmed this immunolocalization. Immunoreactive kallikrein was concentrated in fibroblasts of connective tissue and was not present in collagen fibers. Immunoreactivity was associated with the Golgi complex, free polyribosomes, and rough endoplasmic reticulum. No immunostaining was observed in other subcellular components of fibroblasts.
Journal of Histochemistry and Cytochemistry 01/1989; 36(12):1463-9. · 2.72 Impact Factor
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ABSTRACT: Furosemide was administered for seven days to normal rats. Urinary kallikrein excretion showed a biphasic response during the seven consecutive days of study. During the initial three days only the kininogenase activity showed a significant increase without any variation in the excretion of the immunoreactive kallikrein. The specific urinary kininogenase activity was therefore enhanced. After three days of furosemide administration, both the urinary kininogenase activity and urinary immunoreactive kallikrein were augmented. The urinary specific kininogenase activity was that time no more different when compared to the basal value. Considering the delay time of three days, this second part of the response could be a mineralocorticoid mediated effect. In this respect, kidney level of immunoreactive and kininogenase activity of kallikrein are also increased after seven days of furosemide administration. However the short lasting increase in urinary specific kininogenase activity observed during the initial three days is due to a change in the ratio active versus inactive kallikrein without any variation of total kallikrein. It is possible that this immediate response results of a direct effect of furosemide acting either on the preferential excretion of the active form or on the activation of the prokallikrein in the urine.
Agents and Actions 01/1988; 22(3-4):302-9.
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ABSTRACT: Rat urinary kallikrein (RUK) was purified to apparent homogeneity by a three-step procedure and antibodies were raised in rabbits. Renal kallikrein exists as an active and an inactive form. A specific radioimmunoassay (RIA) was developed to measure directly the total kallikrein. The antibody used in this radioimmunoassay recognized both forms. No cross reactivity was detected with trypsin, esterase A or human urine. When iodinated rat urinary kallikrein was used, the detection range was between 0.125 and 16 ng with 6.5% intraassay variation and 8.1% between assay variation. Intrarenal kallikrein was measured in renal tissue after homogeneisation and solubilisation. Correlations between this RIA and the kininogenase activity or the amidolytic activity were highly significant. Since kallikrein exists as an inactive precursor the direct measurement of the total immunoreactive protein differs from activities determinations. An HPLC ion exchange system has been developed to separate active and inactive forms directly from urine, with a recovery of 79 +/- 11%. This procedure permits measurement of inactive forms. Rat urine contains as much inactive kallikrein as active kallikrein.
Journal of immunoassay 02/1987; 8(1):115-30.
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ABSTRACT: We have previously reported that, although human urinary kallikrein, like glandular kallikreins for other species, releases lysyl-bradykinin from homologous and heterologous substrates, rat urinary kallikrein released a kinin which migrated like bradykinin in CM-cellulose chromatography and polyacrylamide gel electrophoresis (BBA677, 471, 1981). In the study we definitively established the nature of the kinin produced by rat urinary kallikrein by using purified enzyme and substrate, HPLC, radioimmunoassay and N-terminal analysis. Rat urinary kallikrein was purified to apparent homogeneity by a procedure which included affinity chromatography on aprotinin agarose. The kinin produced by rat urinary kallikrein acting on either pure rat high molecular weight kininogen or rat plasma or semipurified bovine and dog plasma was identified as bradykinin. This observation provides the evidence of species differences in the specificity of glandular kallikreins acting on kininogens.
Advances in experimental medicine and biology 02/1986; 198 Pt A:137-45. · 1.09 Impact Factor
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ABSTRACT: In two-kidney, one clip hypertensive rats renal cortical kallikrein was studied one and two weeks following induction of the hypertension in comparison with sham time controls. Cortical active kallikrein was lower in hypertensive rats only at week 2, although blood pressure was significantly higher one week after clipping. Total cortical kallikrein was however never different in sham control and in hypertensive rats. This results provide evidence for a change in the activation of prekallikrein during the onset of Goldblatt hypertension.
Advances in experimental medicine and biology 02/1986; 198 Pt B:279-83. · 1.09 Impact Factor
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ABSTRACT: Renal tissue kallikrein and proteins were measured in two kidney-one clip Goldblatt hypertensive rats both in the stenotic and the controlateral kidney and in sham operated rats at either 1 or 2 weeks after clipping. Activity was assessed by the amidolytic activity and by the kininogenase activity. Kallikrein in normotensive controls was 97.4 +/- 13 ng of bradykinin min-1 mg-1 of protein at week 1 and increased up to 116 +/- 18. Kallikrein in the GH rats was 83 +/- 12 in the stenotic kidney and 85,6 +/- 14 in the controlateral one at week 1, these values remained unchanged at week 2. As a consequence renal tissue kallikrein became significantly lower in the GH rats only at week 2 when compared to controls both the clipped and unclipped kidney showed the same magnitude decrease. Protein concentration remained at a steady level through out the 2 weeks of study. The results suggest that the lower renal kallikrein activity secondary to hypertension found in GH rats result from a decreased activation of prekallikrein in both kidney.
Archives des maladies du coeur et des vaisseaux 11/1984; 77(11):1204-9. · 0.40 Impact Factor
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ABSTRACT: Separate kallikrein excretions [RIA of generated Bradykinins (BK)] and renal functions were measured in 32 two-kidney, one-clip Goldblatt hypertensive (GH) and in 16 sham-operated (SO) rats either one, two, three or four weeks after operation. Mean blood pressure and plasma renin activity were higher in GH rats than in the respective controls. In GH rats, kallikrein excretion was lower from the clipped kidney than from the controlateral one (114 +/- 63 vs 220 +/- 87 ng BK min-1 per 30 min urine collection at week 1, P less than 0.05; 151 +/- 94 vs 425 +/- 125 ng BK min-1 per 30 min urine volume at week 4, P less than 0.01). While the excretion was normal from the controlateral kidney, GH rats had lower total kallikrein excretions than SO rats (335 +/- 138 vs 476 +/- 81 ng BK min-1 per 30 min urine volume at week 1, P less than 0.05; 556 +/- 179 vs 1078 +/- 191 ng BK min-1 per 30 min urine volume at week 4, P less than 0.01). Urinary kallikrein excretion is decreased in 2K-1C Goldblatt hypertension from one week to four weeks after clipping on account of an exclusive reduction in that from the stenotic kidney.
European Heart Journal 12/1983; 4 Suppl G:67-72. · 10.48 Impact Factor
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ABSTRACT: Twenty patients with severe hypertension and chronic renal failure were given Captopril during a one year period. Hypertension was always severe: BP: 193 +/- 11.8 mmHg/120.2 +/- 6.7 mm Hg. Mean glomerular filtration rate (GRF) was 42 +/- 10 ml/mn and renal plasma flow (RPF) was 160 +/- 35 ml/min. Mean plasma renin activity was 1.5 +/- 1.1 ng/ml/h and plasma aldosterone 15.9 +/- 1.9 ng/100 ml. Captopril was given in daily doses from 75 to 300 mg. Furosemide was added in 13 cases, and bêta inhibitions in 10 cases. Blood pressure and renal function were measured eight days, every month end after one year of treatment: the fall in diastolic blood pressure was 13 p. 100 after eight days, 23 p. 100 after one year; a period of at least 6 months was necessary to obtain normal blood pressure values; and after one year blood pressure was normalized (diastolic BP less than 90 mmHg) in 19 patients. Renal function was compared with pretreatment values, after 8 days and one year: --RPF was increased (+18 p. 100 and +10.3 p. 100); --GFR was unchanged (+3,8 p. 100 and -8.8 p. 100); --filtration fraction was significantly decreased: (-12.3 p. 100 and -18.3 p. 100); --sodium excretion rate (+16 p. 100 and +9.9 p. 100) and kaliemia increased (+10 p. 100 and +8 p. 100) but severe hyperkalemia never occurred; --PRA increased (+270 p. 100 and +400 p. 100); --Plasma aldosterone was decreased after eight days --28.9 p. 100 but identical to control after one year -4.4 p. 100. Diuretics were efficient to enhance the antipressor of Captopril, whereas bêta inhibitions appeared less useful, and may be indicated only when tachycardia occurs. These results show that long term use of Captopril alone or associated with Furosemide, can normalise blood pressure in patients with renal insufficiency, without any impairment in GFR, and with an increase in RBF.
Archives des maladies du coeur et des vaisseaux 07/1982; 75 Spec No:151-6. · 0.40 Impact Factor
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ABSTRACT: One limitation of the technique of isolated dog kidney perfusion with heparinized blood is the progressive impairment of the organ function which leads to perfuse separately and simultaneously the two kidneys of the same animal with two identical apparatuses, one of the kidneys being used as a control. In order to overcome this difficulty, we describe a technique of perfusion where the kidney is transposed to the femoral or the carotido-jugular vessels. Interposition of a reservoir and a ventricular pump between the vessels and the kidney secures perfusion at a steady pressure. In 10 experiments, haemodynamics and functions of the kidneys remained steady and nearly normal during a 150 min perfusion.
Journal de physiologie 02/1980; 76(1):83-7.
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Journal d'urologie et de néphrologie 01/1979; 84(12):890-1.
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ABSTRACT: Cadmium exposure is known to induce hypertension, but development of hypertension is not universal in exposed animals. However, the cellular uptake of cadmium could also exert renal cytotoxic effects which have been, until now, essentially only studied at the proximal tubule level. Kallikrein is an enzyme synthetized in renal cortex and excreted in the urine in the distal tubule. Therefore, to evaluate the distal renal effect of cadmium, we studied the daily urinary kallikrein excretion (UKE) in conscious unrestrained female Brown Norway rats during long-term chronic exposure to 2 dosages of cadmium given subcutaneously 3 times a week, a low dose (LD): 0.25 mg/kg and a high dose (HD): 1 mg/kg. Neither dose of cadmium was able to induce significant hypertension in the treated animals. HD administration for 24 weeks resulted in a decreased UKE associated with an increase in plasma renin activity and sodium and potassium excretions. LD administration had no significant effect on UKE. Twenty weeks after stopping cadmium administration, a persistent reduction in UKE was still observed; furthermore, the group which had been previously administered a LD of cadmium, now also exhibited a reduced UKE. During this re-examination period in both groups, the UKE reductions were associated with normal systolic blood pressure, glycosuria, natriuresis. Our data show that cadmium administration can influence UKE, plasma renin activity, plasma aldosterone concentration and electrolyte excretion without inducing any variation of blood pressure. This may reflect a nephrotoxic , non-hypertensive effect. Since this effect persisted after stopping cadmium administration, it may indicate a prolonged irreversible nephrotoxic effect at the distal nephron level. Thus, UKE may be a useful non-invasive index to evaluate distal nephrotoxicity.
Toxicology.
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ABSTRACT: Incubation of a radiolabeled bradykinin analog, [125I]-Tyr8-BK with a crude membrane preparation obtained from isolated rat glomeruli revealed a time dependent binding. The binding was saturable, reversible and was a linear function of protein membrane concentration. The radiolabeled Tyr8-BK bound to a single class of binding sites with an equilibrium dissociation constant (KD) of 3.9±0.7nM and a density (Bmax) of 31±5 fmol/mg protein. The BK-receptor complex was not affected by angiotensin II or by arginine vasopressin and atrial natriuretic factor. BK binding was reversed by bradykinin (Ki = 0.3 10−9 M), and by other kinin analogs in the following order of potency: Lys-BK, Met-Lys-BK, Thi5,8-D Phe7-BK. However, Des-Arg9-BK had no effect on binding of the radiolabelled BK. These results are consistent with the presence of a B2-kinin like receptor in rat glomeruli.
Biochemical and Biophysical Research Communications.
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ABSTRACT: The effect of mercuric chloride on kallikrein content and secretion of renal cortical slices was studied. Mercuric chloride showed dose-dependent inhibition of the secretion of immunoreactive and active kallikrein in the medium associated with a relative increase in the kallikrein tissue content of slices. However the net de novo biosynthesis was also reduced. Active and inactive kallikrein exhibited the same percentage of inhibition indicating that the activation mechanism of prokallikrein was not affected. These results suggest that mercuric chloride exerts an inhibition on tubular secretion but also on the tissular biosynthesis of kallikrein in these in vitro conditions. Morphological study of slices incubated in the presence of mercury also revealed significant tissular lesions which were located on the proximal tubule, but distal tubular changes were also observed. Distal nephrons were identified by the presence of immunoreactive kallikrein with the peroxidase-antiperoxidase method. These ultrastructural alterations included an increase in number and size of lysozomes, vacuoles and lipid droplets. These lesions were associated with an increased release of the lysozomal enzyme N-acetyl-beta-D-glucosaminidase. Since these distal tubular lesions are associated with inhibition of kallikrein secretion which is specifically located in the distal tubule, these results suggest that acute exposure of kidney cortical slices to mercuric chloride causes rapid and marked ultrastructural changes not only on the proximal tubule but also induced structural and biochemical effects at the distal tubule level. As incubation of mercuric chloride did not induce any direct alterations of immunoreactive and active kallikrein, it is likely that the observed inhibition of kallikrein synthesis and secretion are secondary to the morphological lesions.
Renal physiology and biochemistry 13(4):223-32.
