Biomedical subjects

K Kizuki

Publications and source records attributed to K Kizuki.

At least 19 recordsLinked to original sources

PubMed2000

Biochemical and immunohistochemical demonstration of tissue kallikrein in the neuronal nuclei of the developing rat brains.

Kallikrein content and cellular localization in the prenatal, newborn and adult rat brains were determined by the enzyme-linked immunosorbent assay and immunohistochemistry. The content was the highest in the prenatal rats and highly predominant in the neuronal nuclei during the prenatal to newborn periods, whereas the immunoreactive kallikrein was mainly located around neuronal cell bodies and their processes in the adult rats. The preferential nuclear localization in the prenatal rat brains was further confirmed by the immunoblotting technique after the SDS-polyacrylamide gel electrophoresis of the lysate of the nuclei fractionated from the prenatal rat brains. The meaning(s) of this kallikrein localization in the neuronal nuclei at the prenatal and newborn stages is unknown. However, we would like to conclude that this enzyme plays an important role in the morphogenesis of brain by acting on the substance(s) in the neuronal nuclei at the developing stage.

Age Factors↗

PubMed1999

Regression of glomerular injury by kallikrein infusion in Dahl salt-sensitive rats is a bradykinin B2-receptor-mediated event.

AIMS: We investigated whether kallikrein infusion attenuates renal injury in Dahl salt-sensitive rats with hypertension and assessed the role of bradykinin-nitric oxide axis in the renal protection using HOE-140, the bradykinin type-2 (B2) receptor specific antagonist. METHODS: Subdepressor dose of purified rat urinary kallikrein (RUK) (400 ng/day) was continuously infused through the jugular vein by an osmotic mini-pump for 4 weeks in Dahl salt-sensitive (Dahl S) rats fed a high-salt (2% NaCl) diet. RESULTS: Blood pressure increased in a time-dependent manner in Dahl S rats fed a high-salt diet. The RUK infusion did not influence the elevation of blood pressure in Dahl S rats. However, the RUK infusion significantly decreased urinary protein excretion, and increased glomerular filtration rate, as compared with untreated high-salt Dahl S rats. Morphological investigation disclosed that the RUK infusion significantly attenuated glomerulosclerosis and arterial and tubular injuries in the kidney of hypertensive Dahl S rats. The RUK infusion produced an increase in urinary excretions of nitric oxide and cyclic guanosine monophosphate. In addition, the RUK infusion enhanced the generation of nitric oxide from the kidney slices. The functional and morphological effects of the RUK infusion on the kidney were completely lessened by co-administration of the bradykinin B2-receptor antagonist, HOE-140. CONCLUSION: Long-term infusion of subdepressor dose of rat urinary kallikrein attenuates functionally and morphologically the progression of renal injury in Dahl rats susceptible to salt-induced hypertension, and that the protection is mediated by stimulation of bradykinin B2 receptor.

Animals↗

PubMed1998

Potential role of kallikrein in diurnal rhythms and perivascular distribution in rat pineal glands.

Kallikrein hydrolyzes various biologically active peptides, other than kininogens, such as vasoactive intestinal polypeptide (VIP), in vitro. Since kallikrein and VIP have been immunohistochemically shown to be present in the perivascular areas of the pineal gland, this study was designed to determine their topographic proximity in these glands, using immunohistochemical and immunoelectron microscopic double staining methods. Furthermore, since this gland is well-known to have a circadian rhythm, the kallikrein content was measured every 4 h, using a synthetic substrate, Pro-Phe-Arg-MCA, and an enzyme-linked immunosorbent assay (ELISA) to determine whether kallikrein has a circadian rhythm. The immunoreactivities of kallikrein and VIP were highly localized in the perivascular extracellular spaces and were virtually identical in distribution. The kallikrein content changed every 4 h and was high under light and low under dark conditions. The change was more evident when the synthetic substrate was used, and this rhythm was subtle on ELISA. VIP is also said to have a circadian rhythm in the pineal glands, being low under light and high under dark conditions, i.e., opposite to that of kallikrein. Since kallikrein degrades VIP in vitro, it is reasonable to speculate that pineal gland kallikrein is involved in the processing of VIP and possibly other biologically active peptides in the perivascular areas with a discernible circadian rhythm.

Animals↗

PubMed1996

Amino acid sequence of the maize ferredoxin:thioredoxin reductase variable subunit.

The ferredoxin:thioredoxin reductase (FTR) is the essential enzyme of the light dependent regulatory system controlling enzyme activities in oxygenic, photosynthetic cells. This protein is composed of two dissimilar subunits, a catalytic subunit containing a [4Fe-4S] cluster and a redox-active disulfide bridge as the active site, and a variable subunit, whose function is not known yet. Whereas size and primary structure of the catalytic subunit from different organisms seem to be well conserved, they are quite variable for the variable subunit. Here we report the complete amino acid sequence of the variable subunit of maize (Zea mays) FTR established by protein sequencing. The subunit contains 97 residues and has a calculated molecular mass of 10939 Da. A sequence comparison shows 40% identity with the variable subunit from spinach and 38% with the one from Anacystis. The identical residues are grouped in three consensus domains, one near the N-terminus, one in the middle of the subunit and one near the C-terminus. We have obtained some evidence indicating that the N-terminal consensus domain is possibly involved in the interaction with the catalytic subunit.

Amino Acid Sequence↗

PubMed1996

Failure of the oxytocin-induced increase in secretion of urinary kallikrein in young spontaneously hypertensive rats.

Urinary kallikrein excretion during oxytocin (OT) infusion were studied in anesthetized (sodium pentobarbital, 50 mg/kg, i.p.) young (4-weeks-old) spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). OT-infusion (30 nmol/kg/30 min) to WKY significantly increased urinary excretion of the active kallikrein from the basal levels (25.4 +/- 5.6 10(-2) x AU/15 min, n = 5) to 37.3 +/- 5.0 10(-2) x AU/15 min (P < 0.05, n = 5) and 50.7 +/- 17.1 10(-2) x AU/15 min (P < 0.05, n = 5) 15 and 30 min after the start of OT-infusion, respectively. In SHR, OT-infusion did not increase the urinary excretion of active kallikrein, but did decrease the urine volume and sodium excretion. The concentration of the active kallikrein in the kidney of WKY was not changed by OT-infusion, but that of SHR was slightly increased. The OT-infusion resulted in significantly higher concentrations of the active kallikrein in SHR kidney than in WKY kidney. These results suggest that less excretion of urinary kallikrein in SHR during OT-infusion may be attributable to a lower response in the secretion of kallikrein from the kidney.

Animals↗

PubMed1994

Immunohistochemical demonstration of tissue kallikrein in the neurons of rat brain.

The distribution of tissue kallikrein (EC.3.4.21.35) in the rat brain was investigated by an enzyme-linked immunosorbent assay (ELISA) and immunohistochemical technique using antiserum against rat urinary kallikrein. More than 75% of the total amount of kallikrein in the extracts of the cerebral cortex and brain stem was determined by the ELISA to be in the form of prokallikrein, suggesting that the greater part of the enzyme exists in the form of pro-enzyme in the central nervous system. Furthermore, immunohistochemical examination revealed that, although the kallikrein-positive cells were widespread and scattered in the brain, the immunoreactive substances preferentially locate in the neuronal cell bodies and their processes in both the cerebral cortex and brainstem.

Animals↗

PubMed1994

Long-term infusion of kallikrein attenuates renal injury in Dahl salt-sensitive rats.

We investigated whether long-term infusion of kallikrein would attenuate renal injury in salt-induced hypertension in Dahl salt-sensitive rats. A subdepressor dose of purified rat urinary kallikrein (700 ng/d IV) was infused by osmotic minipump for 4 weeks in male Dahl salt-sensitive rats fed a high salt (2% NaCl) diet. This dose did not affect the time-dependent elevation of blood pressure; however, urinary protein excretion was significantly decreased, and glomerular filtration rate was increased. These beneficial effects were reflected morphologically by an attenuation of glomerulosclerotic lesions and tubular injury seen in the hypertensive Dahl salt-sensitive rats. Kallikrein infusion increased urinary excretion of bradykinin and stimulated excretion of cyclic GMP, suggesting that the kallikrein-kinin-prostaglandin and nitric oxide axes were enhanced by rat urinary kallikrein infusion. The alterations induced by kallikrein infusion were potentiated by the concomitant administration of the angiotensin-converting enzyme inhibitor alacepril. These studies indicated that long-term replacement with rat tissue kallikrein attenuates renal injury in hypertensive Dahl salt-sensitive rats.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1994

Tissue kallikrein in rat and mouse neurons.

1. The distribution of tissue kallikrein in the rat brain was investigated by an immunohistochemical technique using antiserum against rat urinary kallikrein. The kallikrein-immunoreactive cells were widespread and scattered in both the cerebral cortex and brain stem, and the immunoreactive substance appeared to be preferentially localized around the neuronal cell body and their processes. 2. Furthermore, in order to define whether brain kallikrein levels vary in the aging process, the hydrolyzing activity in the cerebrum L-prolyl-L-phenylalanyl-L-arginine-4-methyl-coumaryl-7-amide (Pro-Phe-Arg-MCA) was measured in young (7-week old) and old (36-week old) female senescence accelerated mice (SAM-P/8 and SAM-R/1). The brain kallikrein levels of 7- as well as 36-week old SAM-P/8 were found to be lower than those of 7-week old SAM-R/1 (a control strain). Also, the brain kallikrein level of 36-week old SAM-R/1 animals was markedly reduced when compared with the 7-week old mice, suggesting that the reduced amount of cerebral kallikrein reflects the aging of the brain.

Aging↗

PubMed1992

Kallikrein-producing cells in the rat pituitary and pineal gland.

By using an immunohistochemical technique, kallikrein-producing cells in the anterior pituitary of rats were identified to be the same as prolactin-producing cells. Kallikrein was localized at the Golgi apparatus, the rough endoplasmic reticulum and secretory granules. Kallikrein was also located in the perivascular cells of the pineal gland.

Animals↗

PubMed1992

Purification and characterization of the major cationic kallikrein inhibitor in bovine pituitary gland.

The presence of two types of kallikrein inhibitor (cationic and anionic inhibitors) was demonstrated in bovine pituitary gland. These kallikrein inhibitors were separated from the homogenate of bovine posterior pituitary by successive CM-Sephadex chromatography. The major cationic inhibitor was further purified to homogeneity by affinity chromatography using porcine pancreatic beta-kallikrein immobilized on Sepharose 4B and gel filtration. The complete amino acid sequence of this inhibitor was first determined, and it was shown to be a peptide of 58 residues with a calculated molecular weight of 6,511. The Ki value against bovine pituitary kallikrein was 6 x 10(-9) M. The cationic inhibitor was found to be identical with basic pancreatic trypsin inhibitor.

Amino Acid Sequence↗

PubMed1992

Tissue kallikrein clearance by the liver--effect of plasma components on kallikrein uptake by cultured rat hepatocytes.

Rat urinary kallikrein (RUK) injected intravenously to the rat rapidly disappeared from the blood circulation and mainly distributed to the liver. RUK was also incorporated to the primary cultured rat hepatocytes. The amounts of RUK incorporated into the hepatocytes increased by preincubation of RUK with rat plasma. These results and SDS-PAGE analysis suggested some plasma components may be involved in tissue kallikrein clearance in the blood.

Animals↗

PubMed1992

Canine pancreatic kallikrein: enzyme isolation and characterization.

Two forms of canine pancreatic kallikrein, designated as canine pancreatic kallikrein A and B, were separately isolated by ion-exchange, affinity and hydrophobic chromatographies. These enzymes had similar apparent molecular masses, substrate specificities and pH optima. However, kallikrein B was inhibited by soybean trypsin inhibitor, while kallikrein A was not. Both kallikrein A and B were shown by sodium dodecyl sulfate-polyacryl amide gel electrophoresis to consist of two polypeptide chains, designated alpha and beta chains, and binding by disulfide bond(s). The N-terminal amino acid sequences of each alpha and beta chains of kallikrein A and B were determined.

Amino Acid Sequence↗

PubMed1991

Localization of kallikrein in rat pineal glands.

The presence of kallikrein mRNA has been reported in the pineal gland of rats. Using an antibody to rat tissue kallikrein, we immunohistochemically examined the localization of cell components producing tissue kallikrein in this gland. The kallikrein immunoreactive cells were scattered in the parenchyma of the pineal gland. Their cell bodies were polymorphic with cell processes and a large nucleus similar to that of the pinealocyte. Frequently immunoreactive materials were seen to be localized in the perivascular areas.

Animals↗

PubMed1990

Observation of tissue prokallikrein activation by some serine proteases, arginine esterases in rat submandibular gland.

Two serine proteases, arginine esterases (esterases I and II) which showed the activity of tissue prokallikrein activation were identified in rat submandibular gland. These enzymes were separated from the homogenate of rat submandibular gland by two successive DEAE-cellulose chromatographies and were further purified and characterized. Esterases I and II were found to be identical with tonin and esterase B-like enzyme, respectively. Both enzymes activated rat urinary prokallikrein at near neutral pH. Esterase B-like enzyme activated rat urinary prokallikrein better than tonin.

Amino Acid Sequence↗

PubMed1990

Kallikrein- and prolactin-producing cells in the rat anterior pituitary are the same.

Kallikrein-positive cells in the anterior pituitary of female rats were identified to be the same as prolactin-producing cells by using an immunoelectron microscopic method. The kallikrein immunoreactivity was localized at the Golgi apparatus, the rough endoplasmic reticulum, and secretory granules, suggesting that kallikrein is synthesized in the prolactin-producing cells and also may be secreted into the blood vessels.

Absorption↗

PubMed1990

Generation of a different type of beta-kallikrein from porcine pancreatic alpha-kallikrein by the action of chymotrypsin--observation of proteolytic processing occurring around "kallikrein autolysis loop" region.

The generation of a different type of beta-kallikrein, designated C beta-kallikrein, from alpha-kallikrein by chymotryptic action was ascertained by the following observations: 1) When alpha-kallikrein was incubated with chymotrypsin, an increase of esterolytic activity of kallikrein was observed. 2) In sodium dodecyl sulfate polyacrylamide gel electrophoresis, C beta-kallikrein was found to be different from the beta-kallikrein obtained from alpha-kallikrein by tryptic digestion, and was designated T beta-kallikrein. 3) N-Terminal amino acid sequence analyses of internal light and heavy chains of C beta-kallikrein indicated that N-termini of the light and the heavy chains were isoleucine and lysine, respectively, and that the heavy chain had most of the "kallikrein autolysis loop" sequence in its N-terminal end. In the case of T beta-kallikrein, N-termini of the light and the heavy chains were isoleucine and alanine, respectively, and the light chain retained the "kallikrein autolysis loop" region in its C-terminal end. These observations demonstrated that C beta-kallikrein was different from the beta-kallikrein prepared from autolyzed pancreas, A beta-kallikrein, which had lost the "kallikrein autolysis loop" sequence. Structural differences of the above four kallikreins (alpha-, T beta-, C beta-, and A beta-) result in somewhat different enzyme properties. The kinetic constants for the hydrolysis of synthetic substrates (N alpha-benzoyl-L-arginine ethyl ester and N alpha-tosyl-L-arginine methyl ester) of these kallikreins differed from each other, and inhibitory profiles against alpha 1-antitrypsin were also different.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1990

Immunohistochemical localization of kallikrein within the prolactin-producing cells of the rat anterior pituitary gland.

The localization of tissue kallikrein in the pituitary gland of rats was investigated by an immunohistochemical technique using antiserum against rat urinary kallikrein. Kallikrein-positive cells were detected in the anterior lobe of the pituitary of both male and female rats, but were not observed in the posterior lobe of the pituitary in either sex. The kallikrein-positive cells in the anterior pituitary of female rats in oestrus were found to correspond to the prolactin-producing cells, whereas the cells producing GH, LH and ACTH were negative for kallikrein. It is possible, therefore, that the tissue kallikrein may be involved in the production of prolactin and not that of the other anterior pituitary hormones, such as GH, LH, FSH, ACTH and TSH.

Animals↗

PubMed1989

Significance of tissue kallikrein in chronic atrophic gastritis.

Seventy patients were diagnosed to have chronic atrophic gastritis, because an atrophic border was distinguished by the endoscopic Congo red method. The atrophic border was furthermore classified into the closed type and the open type. Specimens of the gastric mucosa were obtained by biopsy to measure tissue kallikrein as a marker of inflammation. The sandwich-type ELISA showed that kallikrein significantly increased with the extension of the atrophic area. Histopathological investigations also revealed that kallikrein markedly increased with the appearance of intestinal metaplasia. The peroxidase-antiperoxidase method located (1) a large amount of kallikrein in the mucous granules which filled the goblet cells found in the mucosa showing intestinal metaplasia and (2) a small amount discharged into lumens. These findings suggested that atrophy of the gastric mucosa might be an inflammatory change, and that the kallikrein-kinin system might be associated with gastric inflammation regardless of the pathological stage.

Biomarkers↗