Endocrinologia Japonica
Online ISSN : 2185-6370
Print ISSN : 0013-7219
ISSN-L : 0013-7219
Volume 38, Issue 6
Displaying 1-20 of 20 articles from this issue
  • MASAO IZAWA
    1991 Volume 38 Issue 6 Pages 577-581
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    In order to further characterize the cDNA clones, pSv-1 and pSv-2, which had been newly isolated from a cDNA library of intact rat seminal vesicles as clones hybridizing to androgen-stimulated mRNAs of approximately 1, 500 and 3, 500 nucleotides in length, respectively, the whole nucleotide sequences were determined. The pSv-1 and pSv-2 were 1135 and 1819 nucleotides in length, respectively, and seemed not to contain entire sequences corresponding to the mRNAs. When the 0.7 kb Hindlll fragments from pSv-1 and the 1 kb fragments from pSv-2 were used to probe rat genomic DNA that had been digested with four restriction enzymes, the Southern blots suggested the existence of multiple genes related to pSv-1 and a single gene related to pSv-2. These results suggest that pSv-1 and pSv-2 provide useful probes not only for further characterization of products encoded by the mRNAs, but also for the study on the physiological roles of androgen-dependent gene expression in rat seminal vesicles.
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  • KUMIKO KOJIMA, YASUO TOTSUKA
    1991 Volume 38 Issue 6 Pages 583-587
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Multiple endocrine neoplasia 2a (MEN 2a) is known to be genetically linked to a locus on chromosome 10. The application of polymorphic DNA probes for the region has made it possible to identify carriers of the disease susceptible gene. We performed DNA analysis for a newly found non-Caucasian MEN 2a family using MEN 203 as a probe. Data from DNA analysis of the family members were concordant with the results of conventional endocrinological tests. Furthermore, DNA analysis discriminated four individuals out of fifteen as non-carriers of the gene with a high degree of certainty. The results relieved these people from taking screening tests for years. DNA analysis employing suitable markers such as MEN 203 appears to be useful for a screening program of MEN 2a in Japanese as well as Caucasians.
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  • KURAJIRO KISHI, MASAHIRO HIRASHIBA, YASUHIKO HASEGAWA
    1991 Volume 38 Issue 6 Pages 589-595
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Rat placental lactogen-II (rPL-II) and growth hormone (rGH) in maternal and fetal serum, amniotic fluid, and placental tissue were measured by a homologous radioimmunoassay during the last half of pregnancy. rPL-II appeared first in maternal circulation and the placental tissue on day 11 of pregnancy. The maternal serum rPL-II concentration increased progressively and reached the peak value (684±76 ng/ml) on day 19, and declined thereafter up to term. rPL-II content in the tissue had a similar pattern to the maternal serum profile of rPL-II, while its concentration in the tissue increased dramatically on day 12 and remained high until day 19. Fetal serum rPL-II was detected on days 17 and 18, though its concentration was much lower (ranged between 3-10ng/ml) than that of maternal serum. rPL-II in amniotic fluid was also detectable only on days 12-14 of pregnancy, and the peak value on day 13 was 22% of the maternal serum rPL-II concentration. The rGH concentration increased gradually as pregnancy advanced with. a decline on the day before parturition. Although rGH in fetal serum increased on day 20 with a decline on the following day, it was slightly detectable in amniotic fluid on the last two days of pregnancy. The molecular profile of rPL-II in amniotic fluid and maternal serum of day 13 pregnant rats were examined by Western blotting. Anti-rPL-II serum detected two proteins with molecular weights (mol wt) of 19.5K and 20.5K in amniotic fluid and one protein with a mol wt of 20.5K in maternal serum under nonreducing conditions. Their migrations coincided with those of purified rPL-II, which migrated as three components of proteins with mol wts of 19.5K, 20.0K, and 20.5K under nonreducing conditions. These results indicate that gestational profiles of rPL-II in maternal serum and the placental tissue were different in their overall pattern and the absolute concentration of rPL-II from those in fetal serum and amniotic fluid, in which rPL-II consisted of monomeric forms of variants.
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  • KUMIKO HIRATO, TAKASI SUZUKI, TAKAAKI HONDO, HIROSHI SAITO, TAKUMI YAN ...
    1991 Volume 38 Issue 6 Pages 597-602
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Steroid sulfatase is a membrane-bound microsomal enzyme, present in various tissues. In this report, data on sulfatase activity in peripheral blood leukocytes isolated from normal women and the characterization of its enzyme are studied. In addition, sulfatase activities in placental sulfatase deficiency (PSD) and ichthyosis patients including ichthyosis vulgaris (IV) and recessive X-linked ichthyosis (RXLI) were analysed and were compared with normal subjects. Steroid sulfatase activity was measured by using tritium labeled steroid sulfate as the reaction substrate. It is demonstrated that human leukocytes contain a sulfatase activity for pregnenolone sulfate (P5-S), dehydroepiandrosterone sulfate (DHA-S) and estrone sulfate (E1-S) respectively. This enzyme has a greatest affinity for P5-S, but the activity for El-S was the highest among the three substrates. The steroid sulfatase activity in female leukocytes is significantly stronger than that in normal males (p<0.001) as determined by the cleavage of DHA-S. Sulfatase in leukocytes obtained from the PSD babies and RXLI patients had lower sensitivity. In the case of the mother affected with PSD, the activity was less than half of that in normal men (p<0.001) and the levels did not overlap with that in normal women. In patients with IV, the activities were in the normal ranges for both males and females. The measurement of leukocyte sulfatase activity would be a clinically useful tool for the diagnosis of PSD carriers and pedigree analysis.
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  • KOICHI KAWAI, AKIYOSHI FUKAMIZU, YASUSHI KAWAKAMI, MASAKO MATSUMURA, K ...
    1991 Volume 38 Issue 6 Pages 603-609
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    A 54-year-old woman was referred to our hospital for the treatment of a tumor of the right chest wall. Clinical examination revealed hypertension, hypokalemia, metabolic alkalosis, hyperaldosteronism and hyperreninemia. Computed tomography and an abdominal echogram indicated a tumor in the right phrenic area and two tumors in the retroperitoneum near the pancreas head. After the surgical resection of these tumors, the primary reninism was diminished. The pathological diagnosis of these tumors was leiomyosarcoma. Plasma active and inactive (trypsin-activated) renin activities (PRA) were 85.7 and 38.9 ng angiotensin I/ml/h, respectively. These PRA did not respond to either postural stimulation or suppression by the volume expansion. Active and inactive renin activities in a right phrenic area tumor were 208 and 32 ng angiotensin I/mg protein /h, respectively. Those of an abdominal tumor were 196 and 30 ng angiotensin I/mg protein/h, respectively. Renin mRNA identical in molecular size to that of the human kidney was identified by northern blot analysis. This is the first case report of renin producing leiomyosarcoma derived from the lung, which is characterized by relatively lower plasma prorenin concentrations.
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  • HIROSHI SHIBATA, ITARU KOJIMA
    1991 Volume 38 Issue 6 Pages 611-617
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The present study was conducted to determine whether protein kinase C was involved in angiotensin II-mediated release of 12-hydroxyeicosatetraenoic acid (12-HETE) from bovine adrenal glomerulosa cells. Activators of protein kinase C, 12-O-tetradecanoylphorbol 4-acetate (TPA) and 1-oleoyl-2-acetylglycerol (OAG), significantly increased release of 12-HETE. The effect of OAG was potentiated by BAYK8644, a stimulator of calcium entry. Sphingosine, H-7 and staurosporine, which inhibited the activity of protein kinase C in vitro, almost completely blocked 12-HETE release induced by TPA. These agents also significantly reduced angiotensin II-mediated 12-HETE release. When time course of the liberation of 12-HETE was measured, angiotensin II elicited sustained release of 12-HETE, which was inhibited by staurosporine. These results indicate that angiotensin II induces sustained release of 12-HETE, a feed forward regulator of aldosterone secretion, and that protein kinase C may be involved in this process.
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  • YOSHIKO HOSHIKAWA, YUKIO SATOH, SHOGO ICHII
    1991 Volume 38 Issue 6 Pages 619-626
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    To identify gene products involved in castration-induced involution of the rat ventral prostate, we constructed a subtraction cDNA library of the ventral prostate from rats castrated for 48 h. The library was screened with subtracted cDNA probes enriched for sequences with a low copy number expressed in intact or castrated rats. As a result of differential screening, 48 cDNA clones representing 10 different induced mRNAs were isolated. The time course of these mRNA inductions after castration was examined. Within the first 24 h after castration, the level of mRNAs for these cDNA clones was significantly increased and it reached its peak by 48-72 h after castration. Although mRNAs for these cDNA clones were expressed in various tissues from intact rats, an increase in mRNA as a response to castration was observed only in the ventral prostate. Partial sequence analyses of the 10 cDNA clones indicate that three cDNA clones represent rat glutathione S-transferase Yb-1, Yb-2 and Yb-3 subunit mRNA sequences, but for others respective homologues could not be found in a search of the GenBank database (release 67).
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  • HIROYUKI NAMBA, SHUNICHI YAMASHITA, HAI-CHENG PEI, NAOFUMI SHIKAWA, MA ...
    1991 Volume 38 Issue 6 Pages 627-632
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    PTC gene, which is derived from the rearranged form of the ret proto-oncogene, was originally discovered in human thyroid papillary carcinomas. This gene has been thought to act as a tumorigenetic factor in thyroid carcinoma, although the action of PTC oncogene products is still unknown. To study the frequency of the PTC gene present in human thyroid carcinomas, we investigated four cell lines derived from thyroid carcinoma and 22 thyroid tumor tissue specimens. The reverse transcriptase-polymerase chain reaction (RT-PCR) method was performed to detect putative PTC mRNA. The presence of the PTC gene in genomic DNA was analyzed by Southern blot hybridization. PTC mRNA was detected by the RT-PCR method in only one papillary carcinoma cell line (TPC-1 cell). Southern gel analysis confirmed the rearrangement of the ret proto-oncogene in this cell line. In the other three cell lines and 22 tumor tissue specimens, however, neither the PTC gene or mRNA was detected. These results demonstrate that the prevalence of the PTC gene in thyroid tumor is low and may not be essential for human thyroid tumorigenesis. That our present results conflict with previous reports may be due to general differences in genetic background among races.
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  • TAKUMA HASHIMOTO, KIYOSHI KAWAI, MACHIKO NISHIBU, SHINICHI FUJITA, HIR ...
    1991 Volume 38 Issue 6 Pages 633-639
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    We examined the effect of endogenous immunoglobulins (G, A and M) and albumin on the measurement of thyroid hormones by different methods, including a new non-isotopic immunoassay of free thyroxine (FT4) and free triiodothyronine (FT3), in a large number of patients with non-thyroidal illness (NTI). Variations in serum protein concentrations can affect the results of radioimmunoassay of human thyroid hormones and thyroxine binding globulin (TBG). Our data revealed that in patients with non-thyroidal illness, when fluctuations in serum γ-globulin occurred the T3/TBG and T4/TBG ratios altered. Consequently, when patients are suffering from non-thyroidal illness with changing γ-globulin levels, clinical scientists should take care when they use T3/TBG and T4/TBG ratios as a substitute for FT3 or FT4 estimation. We found FT4 and FT3 (determined with Amerlex-M kits) T3 and the T3/TBG ratio were altered inversely due to the difference in the serum γ-globulin levels. A recently developed enhanced luminescense enzyme immunoassay for FT3 and FT4 (Amerlite FT3 and FT4 kits) provides more reliable and accurate results, because of its resistance to interference, espeically from albumin and γ-globulin.
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  • TOSHIHIDE YOSHIDA, NORIYA HIRAOKA, MOTOHARU KONDO
    1991 Volume 38 Issue 6 Pages 641-646
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The β3-adrenoceptor agonist, BRL 26830A, which is not inhibited by either β1 or β2-selective antagonists, has been shown to possess anti-obesity and anti-diabetic actions. However, the effects of this agent on insulin and glucagon release have not yet been substantiated. Therefore, we tested the hypothesis that BRL 26830A promotes insulin and glucagon secretion via β3 receptors on pancreatic islet B and A cells. In ICR mice fasted for 48 h, BRL 26830A significantly stimulated insulin secretion from 5 min after administration, markedly decreased blood glucose levels from 30 min after administration, and significantly increased glucagon secretion from 30 min after administration. The administration of a non-selective β-receptor antagonist, at a dose of 50mg/kg, 30 min prior to BRL 26830A injection completely abolished the effects induced by BRL 26830A. However, the administration of a β1-selective antagonist at doses of 50 or 100 mg/kg did not produce any significant effects. On the action of BRL 26830A, whereas the administration of a β2-selective antagonist at 50mg/kg, a near maximal effective dose, partially abolished the effects of BRL 26830A. BRL 26830A had no effect on insulin, glucagon, or glucose levels in streptozocin (STZ) diabetic mice fasted for 48 h. These results suggest that, in mice, BRL 26830A may promote insulin secretion mainly via β3 receptors and partially via β2 receptors on pancreatic-islet B cells, and that glucagon may be secreted as the result of hypoglycemia induced by this agent.
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  • SHIRO MIURA, YOSHIHITO HARA, MAKOTO IITAKA, NOBUHIKO FUKASAWA, KAZUMAS ...
    1991 Volume 38 Issue 6 Pages 647-653
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    To investigate the thyroid function in Bio-Breeding Worcester (BB/W) rats, we have examined the iodine metabolism, serum TSH and thyroid hormone levels in 8-and 16-week-old BB/W and normal Wistar (W) rats. At 8 weeks of age, serum TSH levels were significantly higher in BB/VV rats than in W rats, although there was no difference in the serum levels of free T3 and free T4. Furthermore, the thyroidal radioactive incline incorporation at 48 h was significantly lower in BB/W rats, suggesting that they might have some defects in iodine organification. At 16 weeks of age, serum TSH levels were also significantly higher in BB/W rats than in W rats. Furthermore, serum TSH levels in 16-week-old BB/W rats were significantly higher than in 8-week-old BB/W rats. The thyroid weight was significantly greater in BB/W rats, probably due to the increased serum TSH. The thyroidal radioactive iodine uptake at 48 h and the iodine content in the thyroid homogenates were significantly lower in BB/W rats. These results suggest that BB/W rats have some defect in iodine metabolism resulting in impaired thyroid hormone synthesis.
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  • KENJI MIZUNO, SOITSU FUKUCHI, TADASHI INAGAMI
    1991 Volume 38 Issue 6 Pages 655-660
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    The subcellular localization of renin and immunoreactive angiotensins I and II was studied in rat adrenal cortical tissues. The identity of the immunoreactive angiotensins was confirmed as angiotensin I and angiotensin II by radioimmunoassay and high-performance liquid chromatography, respectively, with reference to standard compounds. By differential centrifugation of tissue homogenate in 0.25 M sucrose/30 mM Tris-HCl/1 mM EDTA, pH 7.4, specific immunoreactive renin was found to be localized principally (60%) in the mitochondrial fraction (P2), whereas about 40% of both angiotensins I and II was contained in the soluble fraction; only 18-20% of both peptides was contained in the P2 fraction. On Percoll density gradient centrifugation of P2, renin was fractionated mostly in a denser band whereas angiotensins I and II were contained in a lighter density area closely corresponding to mitochondrial and lysosomal marker enzymes. These results suggest that renin and angiotensins in the cells of the rat adrenal gland reside in different subcellular compartments and argue against intracellular formation of angiotensins by renin in renin granules.
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  • TE TANG, YIN-Gu WANG, KUMIKO TSUBOI, MINORU IRIE, TAI MA, SIDNEY H. IN ...
    1991 Volume 38 Issue 6 Pages 661-665
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    We have evaluated the role of circulating serum immunoglobulins (IgG) which inhibit the growth of thyroid in the etiology of thyroid atrophy in endemic cretinism. Twenty nongoitrous cretins (13 women and 7 men, age range: 9-33) were classified on the basis of clinical criteria for cretinism in China. They were born and living in an iodine deficient area, Xinjiang, northwest China. Antimicrosomal antibody titers were negative in all serum. Nine patients (seven women and two men; age range: 11-23) were biologically primary hypothyroid. Seven subjects were of a myxedematous form and two subjects were of a mixed form. We have studied thyroid-growth inhibiting immunoglobulin (TGII) activity that was measured as an inhibitory effect of 4mg/ml IgG on TSH-induced [3H]-thymidine incorporation into the DNA of a rat thyroid follicular cell line, FRTL5 cells. Six (five women and one man) out of the nine patients with primary hypothyroidism (66.7 percent) had TGII. We also measured other growth-blocking IgG that inhibited [3H]-thymidine incorporation into DNA stimulated by insulin-like growth factor-I (IGF-I), a growth factor working through a cAMP-independent pathway. Five (three women and two men) out of nine patients (55.6 percent) with nongoitrous primary hypothyroidism had IGF-I-blocking IgG. These results indicate that TGII plays an important role in atrophy of the thyroid in spite of increased serum TSH concentrations, and IgG which inhibits thyroid growth stimulated by IGF-I also might play a role in thyroid atrophy in some endemic cretins. An autoimmune process might be involved in the pathogenesis of hypothyroidism secondary to thyroid atrophy, though severe iodine deficiency is a cause of endemic cretinism.
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  • MAKOTO IITAKA, JUN ISHII, NAOFUMI SHIKAWA, HIROSHI YOSHIMURA, NAOKO MO ...
    1991 Volume 38 Issue 6 Pages 667-671
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    We encountered a patient who developed silent thyroiditis during the course of Graves' disease. The diagnosis of silent thyroiditis was made on the basis of a low thyroidal 131I uptake, no response to the thyrotropin releasing hormone (TRH) test, and subsequent hypothyroidism despite the presence of high titers of thyrotropin (TSH) receptor antibody (TRAb) and thyroid stimulating antibody (TSAb). The patient, in addition, had a discrepancy between serum TSH and thyroid hormone values. This was due to the presence of interfering substances that react to mouse IgG in the sera since serum TSH levels were decreased in a dose dependent manner by the addition of increasing amounts of mouse IgG to the sera. It should therefore be noted that silent thyroiditis can develop in patients with Graves' disease. Furthermore, clinicians should be aware that two-site immunoassay kits that use mouse monoclonal antibodies are subject to interference by some substances, possibly antibodies which react to mouse IgG.
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  • Utilization of Highly Cross-Reactive Antibody Present in Polyclonal Antiserum
    ATSUSHI IWASAWA, HIROAKI HAYASHI, ZEN ITOH, KATSUMI WAKABAYASHI
    1991 Volume 38 Issue 6 Pages 673-681
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    To develop a homologous radiolnlniunoassay (RIA) for a hormone of a small or rare animal often meets difficulty in collecting a large anmount of purified antigen required for antibody production. On the other halld, to employ a heterologous RIA to estimatc the horm me oftell gives poor scnsilivity, To overcome this difficulty, a “hetero-antibody” RIA was studied. In a hetero-antibody RIA system, a purified preparation of a hormone is used for radioiodination and standardization and a heterologous antibody to the hormone is used for the first antibody. Canine motilin and rat LH were selected as examples, and anti-porcine motilin and anti-hCC, and-hCGβ or and-ovine LHβ was used as the heterologous antibody. The sensitivities of the hetero-antibody RIAs were much higher than those of heterologous RIAs in any case, showing that these hetero-antibody RIA systems were suitable for practical use. To clarify the principle of hetero-antibody RIA, antiserum to porcine motilin was fractionated on an affinity column where canine motilin was immobilized. The fraction bound had greater constants of affinity with both porcine and canine motilins than the rest of the antibody fractions. This fraction also reacted with a synthetic peptide corresponding to the C-terminal sequence common to porcine and canine motilins in a competitive binding test with labeled canine motilin. These results suggest that an antibody population having high affinity and cross-reactivity is present in polyclonal antiserum and indicate that the population can be used in hetero-antibody RIA at an appropriate concentration.
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  • JUNICHI TAJIRI, SHIRO NOGUCHI, MITSUO MORITA, MASAAKI TAMARU, NOBUO MU ...
    1991 Volume 38 Issue 6 Pages 683-687
    Published: 1991
    Released on J-STAGE: January 25, 2011
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    This study scrutinizes the correlation between serum free triiodothyronine (FT3) to free thyroxine (FT4) ratios and the eventual outcome of antithyroid drug (ATD) therapy in patients with Graves' disease. Forty-four patients with Graves' thyrotoxicosis were treated with met hvlmercaptoimidazole (methimazole). During the follow-up, 16 patients relapsed in the short period of one to five months after cessation of the drug (relapse group), and 28 patients remained in remission when checked at 12 to 20 months after treatment (remission group). Serum FT3 to FT4 ratios [(pg/ml/ng/dl)×10] were less than 55 throughout ATD therapy in 27 of the 28 remission patients whereas the ratios of the relapse group exceeded 55 from the early phase of methimazole treatment in 10 of 16 patients. In eight of these 10 patients the increased ratios were detected within three months of therapy (1 month, 3 patients; 2 months, 4 patients; 3 months, 1 patient). The ratios for the remaining two patients rose above 55 at the fifth and sixth months. There was no statistical difference between the remission and relapse groups in the FT3 to FT4 ratios either before nor at the completion of the treatment. However, a clear difference could be measured at a point during the therapy. Those in whom this difference was pronounced later underwent relapse. It was therefore concluded that scrutiny of the serum FT3 to FT4 ratio could be a simple and effective method predicting the outcome of antithyroid drug therapy in patients with Graves' disease and furthermore that this ratio could indicate the likelihood of relapse as early as within three months of methimazole treatment, thus saving several. months of patients' and clinicians' time and, when necessary, allowing for early implementation of an alternative therapy.
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  • MAKOTO UJIHARA, KANJI SATO, TAKASHI OHASHI, NAOKI TOMORI, KEIZO KASONO ...
    1991 Volume 38 Issue 6 Pages 689-692
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Familial hypocalciuric hypercalcemia (FHH) is usually characterized by asymptomatic hypercalcemia, mild hypermagnesemia, and low urinary calcium excretion, and is occasionally associated with pulmonary fibrosis. It is inherited as an autosomal-dominant, and no sporadic case of hypocalciuric hypercalcemia has been heretofore reported. This report describes a patient with hypocalciuric hypercalcemia completely compatible with FHH but with no family history, suggesting that the most likely diagnosis is “nonfamilial” hypocalciuric hypercalcemia. We propose that the urinary excretion of calcium be examined in all patients with hypercalcemia, hypophosphatemia, and increased PTH before neck surgery, even if patients have no family history of hypercalcemia.
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  • KAORU NOMURA, YUKO SATO, MAKOTO WATANABE, NOBUO HORIBA, MAKOTO UJIHARA ...
    1991 Volume 38 Issue 6 Pages 693-697
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    We previously reported that ovine and porcine luteinizing hormone (LH) stimulated kidney growth in castrated hypophysectomized rats. Our present study focuses on the physiological role of the renotropic activity of LH isoforms. Plasma LH levels were decreased to 10% of that of castrated control rats by injections of a slow-releasing LHRH agonist, leuprolide acetate, from microcapsules. Compared to controls, which were injected with microcapsules only, the kidney weight in leuprolide-treated castrated rats decreased 12%. Renal protein and DNA contents decreased significantly. Body, liver and spleen weights were not changed by the treatment, however. This effect on the kidney was not observed in castrated hypophysectomized rats, suggesting that leuprolide affected the kidneys indirectly, rather than directly, by suppressing LH secretion. In leuprolide-treated castrated rats, urinary fractional excretion of sodium (FENa) increased, indicating suppressed renal function at the proximal tubules. We concluded that the secretion of renotropically active LH isoforms was regulated at least partially by LHRH and played a physiological role in growth and the function of the proximal tubules.
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  • SHOJIRO NAOMI, TERUHISA UMEDA, TAISUKE IWAOKA, FUMIHIRO MIURA, YASUNOR ...
    1991 Volume 38 Issue 6 Pages 699-703
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Plasma levels of immunoreactive atrial natriuretic peptide (IR-ANP) were measured with a specific radioimmunoassay in 19 undialysed patients with chronic renal failure. At the beginning, an extremely high level of plasma hANP (50 fmol/ml) seen in a patient was rejected with Smirnov's test and was excluded from further statistics. The plasma IR-ANP levels in these patients were significantly higher than those of 19 normal subjects matched with age and sex (10.9±1.6 vs 5.3±0.6 fmol/ml, mean±SEM, p<0.01), and positively correlated with mean blood pressure (r=0.44, p<0.05) and the cardiothoracic ratio (r=0.65, p<0.01), but did not correlate with creatinine clearance (r=-0.38, n.s.). Further, a significant correlation was observed between plasma IR-ANP and urinary protein output (r=0.47, p<0.05). On the other hand, urinary protein output did not correlate significantly with variables such as mean blood pressure, the cardiothoracic ratio or creatinine clearance. Since it has been suggested that ANP enhances glomerular capillary permeability, increased ANP responding to volume overload in those patients may play an important role in increasing urinary protein excretion.
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  • JUN ISHII, SHIGEHIRO KATAYAMA, AKIRA ITABASHI, MOTOHIDE TAKAHAMA, SHOJ ...
    1991 Volume 38 Issue 6 Pages 705-709
    Published: 1991
    Released on J-STAGE: January 25, 2011
    JOURNAL FREE ACCESS
    Calcitonin is widely used in the treatment of post-menopausal osteoporosis. The present study was designed to investigate the effects of salmon calcitonin (SCT) on the incidence of the pituitary tumors in Sprague-Dawley (SD) rats. Subcutaneous injections of SCT at a dose of 160 IU/kg/day for 6 months reduced body weight and induced one pituitary hyperplasia and three pituitary adenomas in 4 of 5 animals, while 5 controls did not show any changes. Prolactin-positive cells were located at the periphery of the affected pituitaries adjacent to the prolactin-negative adenomas. In addition, serum concentrations of prolactin and TSH were lower than in the controls, although serum calcium or LH levels were not significantly different from the controls. Among 7 animals treated with SCT for 6 months followed by no medication for another 6 months, 5 adenomas were detected, one of which had invasive growth toward the adjacent tissue, whereas only one adenoma was found in 9 controls. These results suggest that SCT administration at a high dose may induce the formation of pituitary adenoma, or may accelerate the development of spontaneous pituitary adenomas, some of which show frequent mitotic figures and invasive growth into the surrounding tissue, possibly resulting in malignan transformation. This indicates the need for caution in considering whether calcitonin injections into patients with osteoporosis as well as Paget's disease may induce such pituitary tumors.
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