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M Hosoi

Publications and source records attributed to M Hosoi.

At least 19 recordsLinked to original sources
PubMed1995

Effects of 17 beta-oestradiol and 5 alpha-dihydrotestosterone on the expression of the muscle and heart types of lactate dehydrogenase isozymes in the masseter muscle of developing mice.

17 beta-oestradiol (E2) and/or 5 alpha-dihydrotestosterone (5 alpha-DHT) had no effect on the expression of isozymes of lactate dehydrogenase (LDH) in the masseter muscle of intact male mice. However, treatment with E2 restored the level of the muscle (M) type of LDH isozyme, which had been reduced by testectomy, to that found in intact male mice treated with vehicle only. Moreover, 5 alpha-DHT alone was more effective than E2 in increasing the relative level of this isozyme in testectomized mice. 5 alpha-DHT had a more significant effect on the increase in the relative level of the M-type LDH isozyme when combined with E2. These results suggest that androgens promote, in the presence of oestrogens, the postnatal changes in the characteristics of the masseter muscle of developing male animals.

Animals↗
PubMed1995

Beta-glycerophosphate accelerates calcification in cultured bovine vascular smooth muscle cells.

Calcification is a common feature of advanced atherosclerotic lesions and is being reemphasized as a clinically significant element of vascular disease. However, the scarcity of in vitro models of vascular calcification preclude studying its molecular and cellular mechanism. In the present study, we describe an in vitro calcification in which diffuse calcification can be induced by culturing bovine vascular smooth muscle cells (BVSMC) in the presence of beta-glycerophosphate, ascorbic acid, and insulin in a manner analogous to in vitro mineralization by osteoblasts. Calcification was confirmed by von Kossa staining and 45Ca accumulation. Factor analysis revealed that beta-glycerophosphate is the most important factor for this calcification process, suggesting that alkaline phosphatase (ALP) may be involved. As predicted, high levels of ALP expression were detected by ALP assay and Northern blot analysis. Functional significance of ALP was confirmed by demonstrating that levamisole, a specific inhibitor of ALP, inhibited BVSMC calcification in a dose-dependent manner. Bisphosphonates such as etidronate and pamidronate potently inhibited BVSMC calcification, suggesting that hydroxyapatite formation may be involved. Importantly, expression of osteopontin mRNA was dramatically increased in calcified BVSMC compared with uncalcified control cells. These data suggest that beta-glycerophosphate can induce diffuse calcification by an ALP-dependent mechanism and that this in vitro calcification system is useful for analyzing the molecular and cellular mechanisms of vascular calcification.

Alkaline Phosphatase↗
PubMed1994

Adenocarcinoma in the rectum of a capped langur (Presbytis pileata).

A rectal adenocarcinoma in a 22-year-old capped langur histologically resembling those in human cases is reported. An ill-defined diffuse tumor with fibrously firm rectal wall showed diffuse infiltrative growth of signet-ring cancer cells. Immunohistochemistry demonstrated positive staining for CEA, lysozyme, EMA, keratin and B72.3.

Animals↗
PubMed1994

Gastric adenocarcinoma in a cougar (Felis concolor).

Diffusely invasive tumors occurred in the stomach of a 9-year-old female cougar (Felis concolor) from a zoo in Japan. The tumors consisted of tubular adenocarcinoma cells, and had infiltrative growth to the submucosa and muscularis propria. Tumor cells were positive for carcinoembryonic antigen (CEA), lysozyme, epithelial membrane antigen (EMA), gastrin, alpha-1-fetoprotein (AFP), keratin, and B72.3. Mucin-like materials occurred within cytoplasmic vacuoles.

Adenocarcinoma↗
PubMed1992

Trigeminal nerve endings of lingual mucosa and musculature of the rat.

Horseradish peroxidase conjugated with wheat germ agglutinin (HRP-WGA) was injected into the trigeminal ganglion of adult rats to label the peripheral sensory receptors of the tongue. The conjugate was transported anterogradely to all the ipsilateral fungiform papillae and filiform papillae. Some labeled fibers crossed over to the contralateral papillae. In the intrinsic tongue muscle undulating nerve fibers along or across muscle fibers were often observed, and formed simple spiral endings.

Animals↗
PubMed1992

Effects of prorenin on blood pressure and plasma renin concentrations in stroke-prone spontaneously hypertensive rats.

To examine the possible activation of prorenin in the circulation, recombinant rat prorenin was intravenously given to pentobarbital-anesthetized rats. Bolus injection of prorenin at the dose of 100 micrograms angiotensin I (ANG I).h-1.kg-1 into Wistar rats, leading to a 15-fold increase in plasma prorenin concentrations (from 27 +/- 6 to 393 +/- 75 ng ANG I.h-1.ml-1) at 5 min after the injection, did not affect blood pressure, heart rate, and plasma active renin concentrations throughout experiments. On the other hand, the administration of active renin at the dose of 1, 3, and 10 micrograms ANG I.h-1.kg-1 increased mean blood pressure of Wistar rats by 8 +/- 2, 15 +/- 2, and 27 +/- 4 mmHg, respectively. Similar results were obtained in Wistar rats at 18 h after bilateral nephrectomy. These results confirmed no activation of prorenin in the circulation of normotensive rats. The activation of prorenin was also examined on both stroke-prone spontaneously hypertensive rats (SHRSP) and 18 h-nephrectomized SHRSP. There was no rise in blood pressure or plasma active renin concentrations in both groups of SHRSP after injection of prorenin. Thus the elevated plasma active renin in SHRSP [Shibota, M., A. Nagaoka, A. Shino, and T. Fujita. Am. J. Physiol. 236 (Heart Circ. Physiol. 5): H409-H416, 1979] seems to be caused by the enhanced release of active renin from the kidney rather than the activation of circulating prorenin.

Animals↗
PubMed1992

Adrenal and circulating renin-angiotensin system in stroke-prone hypertensive rats.

The plasma and adrenal renin-angiotensin system in stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto (WKY) rats were examined in animals at 5, 11, 18, and 25 weeks of age. Plasma active renin was significantly increased in 18- and 25-week-old SHRSP with impaired renal function, whereas there was no difference in the plasma prorenin level or renal renin content between the two strains at all ages examined. Thus, the rate of activation of prorenin seems to be enhanced in the kidney of SHRSP with malignant hypertension. Adrenal renin contents were severalfold higher in SHRSP than WKY rats at all ages. However, adrenal angiotensin peptides were not increased in SHRSP aged 5 and 11 weeks. In 18-week-old SHRSP, adrenal angiotensin II (Ang II) and III (Ang III) levels were fourfold and 1.8-fold higher, respectively, than in WKY rats, accompanied by 1.5-fold higher plasma aldosterone. Increased adrenal angiotensin and plasma aldosterone were also found in 25-week-old SHRSP. Zonal distribution studies indicated that the elevated Ang II and III in SHRSP were derived mainly from the capsular tissue (the zona glomerulosa). To examine the contribution of circulating angiotensin to the adrenal angiotensin content, effects of bilateral nephrectomy on adrenal angiotensin and renin were examined in 18-week-old rats. At 24 hours after nephrectomy, plasma angiotensin, prorenin, and active renin were decreased to almost negligible concentrations. Conversely, in both adrenal capsular and decapsular tissues of SHRSP and WKY rats, neither angiotensin nor renin was significantly decreased after nephrectomy. These results suggest that the increase in adrenal capsular Ang II contents in SHRSP may be partly due to an enhanced local production of Ang II.

Adrenal Glands↗
PubMed1992

Evidence for the presence of differently glycosylated forms of prorenin in the plasma of anephric man.

Previously, we unexpectedly observed that plasma inactive renin (trypsin-activatable renin) in bilaterally nephrectomized rats is not prorenin. To determine whether plasma inactive renin in anephric man is prorenin, we examined the immunological and biochemical properties of plasma inactive renin from five anephric patients. There were significant concentrations of inactive renin (5.33 +/- 2.08 ng/L.s) in plasma of anephric patients, while active renin was negligible (0.06 +/- 0.01 ng/L.s). The inactive renin from anephric patients could be immunoprecipitated 97 +/- 1% by specific antiserum against the prosegment portion of prorenin. Specific antimature renin serum completely inhibited the angiotensin-I-generating activity of inactive renin induced by trypsin treatment. The molecular mass of inactive renin from anephric patients (49.0 +/- 0 kDa), estimated by gel permeation high performance liquid chromatography, was similar to that of normal human plasma prorenin (48.2 +/- 0.8 kDa). These results indicate that plasma inactive renin in anephric man is prorenin, findings different from our previous observations obtained in anephric rats. Concanavalin-A chromatography separated inactive renin from anephric patients into three forms, including the column-unbound form, the loosely bound form, and the tightly bound form. Thus, in anephric man, differently glycosylated multiple forms of prorenin are released into the circulation from an extrarenal organ(s).

Adult↗
PubMed1991

Increased production of angiotensin II in the adrenal gland of stroke-prone spontaneously hypertensive rats with malignant hypertension.

Angiotensin(Ang) contents in the adrenal gland of stroke-prone spontaneously hypertensive rats(SHRSP) and age-matched Wistar Kyoto rats(WKY) were determined using reverse phase high performance liquid chromatography combined with a specific radioimmunoassay. In normotensive 5 wk-old SHRSP, the adrenal renin activity was about 3 times higher than that of age-matched WKY while the adrenal Ang I and Ang II concentrations did not differ from those of WKY. In the severely hypertensive 25 wk-old SHRSP, the adrenal Ang II and Ang I, and plasma aldosterone concentrations were about 5-fold, 2-fold and 4-fold, respectively, increased compared with levels in the WKY. In the 25 wk-old SHRSP 24 h after bilateral nephrectomy, the adrenal Ang II and plasma aldosterone levels were not decreased and were 10 and 3 times, respectively, higher than those of nephrectomized control WKY. Thus, the enhanced local generation of Ang II in the adrenal gland may contribute to the increased release of aldosterone in SHRSP with malignant hypertension.

Adrenal Glands↗
PubMed1991

Similarity between physicochemical properties of recombinant rat prorenin and native inactive renin.

Rat prorenin was synthesized by Chinese-hamster ovary cells transfected with an expression vector containing rat preprorenin cDNA sequences, then purified by concanavalin A-Sepharose chromatography and h.p.l.c. on G3000SW. The molecular mass of purified prorenin was 46,000 Da, as determined by h.p.l.c. on G3000SW. Immunoblot analysis indicated that recombinant prorenin cross-reacted with anti-(mature renin) antibody and two kinds of antibodies recognizing the N-terminus and C-terminus of the prosegment of rat prorenin. Recombinant prorenin was bound to a Cibacron Blue-Sepharose column and eluted with 1.4 M-NaCl, but was not retained by an octapeptide renin inhibitor (H-77)-Sepharose column. Trypsin activation of prorenin increased the renin activity 110-fold, caused binding to an H-77-Sepharose column and nullified the reactivity to the above two kinds of anti-prosegment antibodies, findings indicating that the activation of prorenin with trypsin is due to the cleavage of the prosegment. Rat plasma inactive renin, partially purified by h.p.l.c. on G3000SW, had much the same physicochemical characteristics as the recombinant prorenin. These results provide evidence that rat plasma inactive renin is prorenin. Recombinant prorenin is a useful material for examining the physiological role of circulating prorenin.

Animals↗
PubMed1991

Amino-terminal amino acid sequence and heterogeneity in glycosylation of rat renal renin.

We isolated 7.4 mg of pure renin from 2 kg of rat kidneys using affinity chromatography on pepstatin-aminohexyl-Sepharose and an octapeptide renin inhibitor, H-77-Sepharose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that renin consists of two polypeptide chains linked by a disulfide bond, one of Mr = 36,000 (heavy chain) and the other of Mr = 3,000 (light chain). The amino-terminal 10-amino acid sequences of the heavy and the light chains were identical to the sequences beginning at Ser72 and Asp355, respectively, of the amino acid sequence of preprorenin deduced from the renin cDNA sequence. Amino acid sequencing of the carboxyl-terminal peptide of the heavy chain, generated by digestion with lysyl endopeptidase, showed that the carboxyl-terminal residue of the heavy chain is Phe. Thus, the propeptide of prorenin is cleaved after Thr71, followed by removal of two amino acids, Arg353 and Asn354, the result being formation of the heavy and light chains. Thus, the site of cleavage of rat prorenin is after a nonbasic amino acid, in contrast to the cleavage of the propeptide after a pair of basic amino acids in mouse submaxillary renin, human renal renin, and many secretory proteins. Treatment of renin with neuraminidase or glycopeptidase F had no apparent effect on the charge heterogeneity of renin. Glycosylation probably does not contribute to charge heterogeneity.

Amino Acid Sequence↗
PubMed1991

Evidence for heterogeneity of glycosylation of human renin obtained by using lectins.

1. In this study, the carbohydrate structure of pure human renin was examined by using various lectins. 2. Pure renin could be separated into three forms by concanavalin A chromatography, a concanavalin A-unbound form, a loosely bound form and a tightly bound form, termed renins A, B and C, respectively. Renins A, B and C accounted for 3, 13 and 84%, respectively, of the purified renin. These forms were all present in individual human plasma and the relative proportions in plasma were 27 +/- 3, 33 +/- 4 and 39 +/- 5% (means +/- SEM) for renins A, B and C, respectively (n = 5). 3. Each form, electroblotted on to the nitrocellulose sheet after gel electrophoresis, was incubated with five peroxidase-labelled lectins, lentil lectin, erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin, Ricinus communis agglutinin and peanut agglutinin. The protein was stained with 4-chloro-1-naphthol. 4. The staining pattern obtained with these lectins was significantly different among the three forms of human renin, confirming that they have different carbohydrate structures. Furthermore, the positive staining of human renin with erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin and Ricinus communis agglutinin was in contrast with the lack of binding of rat renin to these lectins. 5. These results indicate the renal secretion of differently glycosylated multiple forms of human renin. The carbohydrate structure of human renin appears to differ from that of rat renin.

Animals↗
PubMed1991

Biochemical and immunological differences between plasma inactive renin from normal and nephrectomized rats.

Using immunological techniques, we have demonstrated that about half the trypsin-activatable renin in normal rat plasma is prorenin, while the other is not, and that inactive renin in nephrectomized rat plasma is not prorenin. In the present study, the trypsin-induced angiotensin I generating activity not related to prorenin from normal rat plasma disappeared after HPLC on G3000SW. HPLC analysis of trypsin-treated plasma showed the generation of active renin by trypsin for normal rat plasma, while it did not for nephrectomized rat plasma. These results indicate that trypsin treatment of crude plasma results in the generation of angiotensin I generating activity not due to prorenin, as well as activation of prorenin. HPLC on G3000SW is a useful tool for the determination of plasma prorenin.

Angiotensin I↗
PubMed1991

Immunological evidence that kidney is primary source of circulating inactive prorenin in rats.

To determine whether or not rat plasma inactive renin is prorenin, specific antibodies were raised against two 15-amino acid peptides, Pro-NH2 and Pro-COOH, which contained the NH2-terminal and COOH-terminal sequences, respectively, of the prosegment of rat prorenin. Inactive renin was measured after trypsin treatment. Immunoaffinity chromatography of normal rat plasma on anti-Pro-NH2 and anti-Pro-COOH immunoglobulin G (IgG)-Sepharose showed that about one-half the amount of inactive renin was prorenin, whereas the rest was neither prorenin nor renin. Thus trypsin treatment of the unfractionated plasma does not provide measurement of the concentration of prorenin. However, fractionation of plasma by high-performance liquid chromatography on G3,000SW columns followed by trypsin treatment led to the measurement of prorenin. Prorenin and active renin concentrations in the normal plasma of conscious rats were 44.3 +/- 5.8 and 13.3 +/- 1.4 (SE) ng ANG I.h-1.ml-1, respectively (n = 10). On the other hand, plasma inactive renin from rats at 24 h after bilateral nephrectomy bound to neither anti-Pro-NH2 nor anti-Pro-COOH IgG immunoaffinity columns, and the enzymatic activity after trypsin treatment was not inhibited by anti-mature renin IgG. These results demonstrate that inactive renin from nephrectomized rats was not prorenin. Thus the kidney is the primary source of circulating prorenin in rats.

Amino Acid Sequence↗
PubMed1990

Disproportional release of differently glycosylated forms of human renin by furosemide.

Concanavalin A (con A) chromatography of human plasma revealed the presence of three differently glycosylated forms of active renin(AR) and prorenin(PR), including the con A unbound forms(AR-I and PR-I), the loosely-bound forms (AR-II and PR-II), and the tightly-bound forms (AR-III and PR-III). These three forms of AR and PR were observed in human renal extracts. Normal male volunteers were intravenously given the diuretic furosemide (20 mg), kept standing for one hr and the effect on each form of renin was examined. These treatments elevated the plasma concentrations of AR-I, II and III by 2.1 +/- 0.2, 2.6 +/- 0.5, and 6.3 +/- 1.1-fold, respectively (n = 12), thereby indicating that the increase in AR-III was significantly larger than that in the other two forms (P less than 0.01). This disproportional increase was accompanied by a significant increase in the relative percent of AR-III in plasma from 21.6 +/- 2.5 to 42.2 +/- 3.0% (P less than 0.01). On the other hand, increase in the plasma levels of PR-I, II, and III was small (1.4 +/- 0.1, 1.0 +/- 0.1, and 1.1 +/- 0.2-fold, respectively). These results provide evidence for the presence of differently glycosylated forms of AR and PR in human plasma and suggest the preferential release of AR-III with the acute stimulation of renin, by furosemide.

Adult↗
PubMed1990

Conversion to renin of exogenously administered recombinant human prorenin in liver and kidney of monkeys.

Highly purified recombinant human prorenin, labeled with 125I (125I-prorenin), was intravenously given to monkeys to examine the possible in vivo conversion of this prorenin to renin. 125I-prorenin and 125I-renin were detected using specific anti-prorenin prosegment antibody and anti-renin antibody, respectively. The plasma disappearance of immunoreactive 125I-prorenin in marmosets showed two exponential components with a half-life of 10.4 +/- 0.2 min for the rapid component and 165.7 +/- 12.6 min for the slow component. Fifteen minutes after the injection of 125I-prorenin, 38.7 +/- 2.8 and 3.9 +/- 0.5% of the administered dose accumulated in the liver and kidney, respectively. Less than 1% of the dose injected distributed in the other organs, including the brain, submandibular gland, lung, heart, aorta, adrenal gland, spleen, uterus, ovary, and testis. Thus the labeled prorenin was predominantly taken up by the liver and kidney. Analysis of liver and kidney extracts and plasma, by both gel permeation high-performance liquid chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, demonstrated that 125I-prorenin (Mr = 46,000) taken up by the liver and kidney was significantly converted to 125I-renin (Mr = 42,000), whereas only a negligible amount of 125I-renin (Mr = 42,000) was present in the plasma. Although there seems to be no activation of prorenin in the blood circulation, prorenin does seem to be activated by the liver and kidney.

Animals↗