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H Takemori

Publications and source records attributed to H Takemori.

At least 19 recordsLinked to original sources
PubMed2001

Identification of essential residues for catalysis of rat intestinal phospholipase B/lipase.

Intestinal brush border membrane-associated phospholipase B/lipase (PLB/LIP) consists of four tandem homologous domains (repeats 1 through 4) and a COOH-terminal membrane binding domain, and repeat 2 is the catalytic domain that catalyzes phospholipase A2, lysophospholipase, and lipase activities. We examined the structural basis of the catalysis of PLB/LIP with this unique substrate specificity by site-directed mutagenesis of recombinant repeat 2 enzyme. Ser414 and Ser459 within the active serine-containing consensus sequence G-X-S-X-G in the best-established lipase family were dispensable for activity. In contrast, substitution of Ala for Ser404 almost completely inactivated the three lipolytic activities of PLB/LIP, even though the gross conformation was not altered as determined by CD spectroscopy. Notably, this Ser is located within the conserved G-D-S-L sequence on the NH2-terminal side in lipolytic enzymes of another group proposed recently. Furthermore, mutagenesis and CD spectroscopic analyses suggested that Asp518 and His659, lying within conserved short stretches in the latter group of lipolytic enzymes, were essential for activity. These three essential residues are conserved in the known PLB/LIP enzymes, suggesting that they form the catalytic triad in the active site. These results indicate that PLB/LIP represents a distinct class of the lipase family. PLB/LIP is the first mammalian member of that family. Repeat 2 is equipped with the triad, but not the other repeats, accounting for why only repeat 2 is the catalytic domain. Replacing Thr406 with Gly, matching the enzyme's sequence to the lipase consensus sequence exactly, led to a great decrease in secretion and accumulation of inactive enzyme in the cells, suggesting a role of Thr406 in the structural stability.

Amino Acids↗
PubMed2001

Histamine production by cultured microglial cells of the mouse.

We previously reported that cells other than mast cells or neurons could synthesize histamine in response to lipopolysaccharide (LPS) or interleukin 1beta in the rat brain. To identify the responsible cells, we examined histidine decarboxylase (HDC) activity and the expression of HDC mRNA in GMI 6-3 mouse microglial cells. Both the activity and mRNA for HDC in GMI 6-3 cells were induced by LPS treatment, and the induction was sensitive to calmodulin-dependent kinase II inhibitor, KN62. These findings indicate that microglia is a third cell type producing histamine in the brain.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2001

Characterization of a proximal element in the rat preadipocyte factor-1 (Pref-1) gene promoter.

Preadipocyte factor-1 (Pref-1) was shown to negatively regulate adipocyte differentiation. We recently reported that ZOG, a rat homolog of Pref-1, was specifically expressed in the adrenal zona glomerulosa. Results of the investigation of Pref-1 expression in preadipocyte and in undifferentiated adrenal cortex suggested that down-regulation of Pref-1 gene was closely correlated with the differentiation process. In this study we demonstrate that an upstream region (from -76 to -47) of the rat Pref-1 gene was essential for its expression in adrenocortical carcinoma-derived H295R cells. A nucleotide sequence found in this region, GCGTGGGCGTGGGCGGGGG (Egr/GC-box), seemed to contain three elements, two early growth response (Egr) elements and one GC-box, overlapping each other. Mutations of four or five nucleotides in a 7-nucleotides-stretch in the midst of the Egr/GC-box eliminated the binding of Sp1/3, abolished the activation by Egr-factor(s) and diminished the Pref-1 promoter activity. When mutations were introduced into the outside of the middle portion, the binding of Sp1/3 to the Egr/GC-box was abolished similarly. However, the decrease in the promoter activity was less than that found with the construct mutated at the middle. These results indicated that an element present at the 7-nucleotides-stretch in the midst of the Egr/GC-box might be important for the Pref-1 promoter activity, and this proximal element was possibly activated by a still-unidentified nuclear factor(s). This element would function as the promoter of the Pref-1 gene in H295R cells, but not in HeLa cells.

Adipocytes↗
PubMed2001

Identification of the rat adrenal zona fasciculata/reticularis specific protein, inner zone antigen (IZAg), as the putative membrane progesterone receptor.

Using immunological methods, a protein specific to the inner zones of the rat adrenal cortex, and called inner zone antigen (IZAg), was previously shown to have two interrelated forms of 26 kDa (IZAg1) and 55-60 kDa (IZAg2), and to have an action on steroid hydroxylation. After two-dimensional gel electrophoresis, and immunoaffinity column purification, N-terminal amino-acid analysis showed that the first 12 amino acids were identical to those of a recently described putative membrane located progesterone receptor (PPMR). RT-PCR was then used to generate the cDNA of this protein, using RNA extracted from rat adrenals. A glutathione S-transferase (GST)-fusion construct was expressed in Escherichia coli, and shown to generate an immunoreactive product of molecular mass consistent with its identification as IZAg1. More detailed examination of the distribution of this protein, not only in the zona fasciculata/reticularis of the adrenal cortex, but also in the Leydig cell, kidney and liver, suggest it may have a role in steroid hormone synthesis and/or metabolism.

Amino Acid Sequence↗
PubMed2001

Salt-inducible kinase is involved in the ACTH/cAMP-dependent protein kinase signaling in Y1 mouse adrenocortical tumor cells.

The involvement of salt-inducible kinase, a recently cloned protein serine/threonine kinase, in adrenal steroidogenesis was investigated. When Y1 mouse adrenocortical tumor cells were stimulated by ACTH, the cellular content of salt-inducible kinase mRNA, protein, and enzyme activity changed rapidly. Its level reached the highest point in 1-2 h and returned to the initial level after 8 h. The mRNA levels of cholesterol side-chain cleavage cytochrome P450 and steroidogenic acute regulatory protein, on the other hand, began to rise after a few hours, reaching the highest levels after 8 h. The salt-inducible kinase mRNA level in ACTH-, forskolin-, or 8-bromo-cAMP-treated Kin-7 cells, mutant Y1 with less cAMP-dependent PKA activity, remained low. However, Kin-7 cells, when transfected with a PKA expression vector, expressed salt-inducible kinase mRNA. Y1 cells that overexpressed salt-inducible kinase were isolated, and the mRNA levels of steroidogenic genes in these cells were compared with those in the parent Y1. The level of cholesterol side-chain cleavage cytochrome P450 mRNA in the salt-inducible kinase-overexpressing cells was markedly low compared with that in the parent, while the levels of Ad4BP/steroidogenic factor-1-, ACTH receptor-, and steroidogenic acute regulatory protein-mRNAs in the former were similar to those in the latter. The ACTH-dependent expression of cholesterol side-chain cleavage cytochrome P450- and steroidogenic acute regulatory protein-mRNAs in the salt-inducible kinase-overexpressing cells was significantly repressed. The promoter activity of the cholesterol side-chain cleavage cytochrome P450 gene was assayed by using Y1 cells transfected with a human cholesterol side-chain cleavage cytochrome P450 promoter-linked reporter gene. Addition of forskolin to the culture medium enhanced the cholesterol side-chain cleavage cytochrome P450 promoter activity, but the forskolin-dependently activated promoter activity was inhibited when the cells were transfected with a salt-inducible kinase expression vector. This inhibition did not occur when the cells were transfected with a salt-inducible kinase (K56M) vector that encoded an inactive kinase. The salt-inducible kinase's inhibitory effect was also observed when nonsteroidogenic, nonAd4BP/steroidogenic factor-1 -expressing, NIH3T3 cells were used for the promoter assays. These results suggested that salt-inducible kinase might play an important role(s) in the cAMP-dependent, but Ad4BP/steroidogenic factor-1-independent, gene expression of cholesterol side-chain cleavage cytochrome P450 in adrenocortical cells.

Adrenal Cortex Neoplasms↗
PubMed2001

Differential regulation of 3beta-hydroxysteroid dehydrogenase type II and 17alpha-hydroxylase/lyase P450 in human adrenocortical carcinoma cells by epidermal growth factor and basic fibroblast growth factor.

Epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) are pluripotent growth factors that stimulate both the proliferation and steroidogenesis of adrenocortical cells. Here we demonstrate that EGF and bFGF specifically induce mRNA of 3beta-hydroxysteroid dehydrogenase type II (3betaHSD II) and suppress that of 17alpha-hydroxylase/lyase P450 (CYP17) in human adrenocortical H295R cells. The induction of 3betaHSD II mRNA did not occur until 6 h after the growth factor treatment and was completely abolished in the presence of a protein synthesis inhibitor, cycloheximide (CHX), suggesting that the induction required de novo protein synthesis. The CYP17 mRNA suppression began at almost the same time as the induction of the 3betaHSD II mRNA. Interestingly, the CYP17 mRNA level was increased by the CHX treatment. Both the 3betaHSD II and CYP17 mRNAs were repressed by treatment with a calmodulin kinase II (CaMK II) inhibitor, KN-93, and were enhanced by a mitogen-activated protein kinase (MAPK) inhibitor, PD98059. The PD98059-mediated induction of the 3betaHSD II mRNA was completely blocked by the CHX treatment. Interestingly, treatment with EGF in the presence of both PD98059 and CHX produced a greater increase in the CYP17 mRNA than did treatment in the presence of PD98059 alone. These results suggest that CHX-sensitive factor(s) and CaMK II- and MAPK-signaling pathways may have important roles in both induction of 3betaHSD II and suppression of CYP17 by EGF or bFGF in H295R cells.

3-Hydroxysteroid Dehydrogenases↗
PubMed2000

Molecular cloning of NADPH-cytochrome P450 oxidoreductase from silkworm eggs. Its involvement in 20-hydroxyecdysone biosynthesis during embryonic development.

Using RT-PCR, a cDNA fragment of NADPH-cytochrome P450 oxidoreductase from silkworm, Bombyx mori, was cloned from three-day-old nondiapause eggs. RACE was used to isolate the ends of the DNA. The full-length cDNA obtained was composed of 3471 bp with an open reading frame encoding a protein of 687 amino-acid residues with a relative molecular mass of 77 700. The protein, fused with glutathione S-transferase, was expressed in Escherichia coli and purified to homogeneity. The fused protein not only had NADPH-dependent cytochrome c-reducing activity, but also acted as an electron carrier from NADPH to bovine adrenal 21-hydroxylase P450 in the steroid hydroxylation reaction, confirming that the protein is the silkworm NADPH-cytochrome P450 oxidoreductase. Ecdysone 20-hydroxylase activity in the nondiapause egg microsomes increased until the fourth day after oviposition, and then decreased, little being detected on the ninth day. An antibody raised against the P450 reductase inhibited the ecdysone hydroxylation. Immunoblot analyses of the microsomes indicated that the P450 reductase protein appeared distinctly in the three-day-old nondiapause eggs and, in contrast to the developmental pattern of ecdysone hydroxylase activity, continued to increase as the embryos developed. These results suggest that ecdysone hydroxylation in the early stage of embryogenesis is dependent on the presence of both P450 reductase and ecdysone 20-hydroxylase P450, but its gradual reduction in the later stage may be due to the decrease in the level of ecdysone 20-hydroxylase P450.

Amino Acid Sequence↗
PubMed2000

SIK (Salt-inducible kinase): regulation of ACTH-mediated steroidogenic gene expression and nuclear/cytosol redistribution.

Possible involvement of salt-inducible kinase (SIK), a serine/threonine protein kinase first cloned from high K+-diet treated rat adrenal glands, in the regulation of steroidogenesis was investigated. Y-1 cells, when treated with ACTH, underwent a rapid change in SIK's mRNA content. It reached the maximum within a few hours and returned to the base after 8 h. In contrast, the levels of mRNAs for CYP11A and StAR protein reached the maxima after 8 h. The SIK's mRNA induction failed to occur in ACTH-, forskolin- or 8-Br-cAMP-treated Kin-7 cells, a mutant cell line of Y-1 with defective cAMP-dependent protein kinase A (PKA). Y-1 cells that overexpress SIK, when treated with ACTH, had significantly repressed levels of mRNAs for CYP11A and StAR protein. Therefore, SIK might have a negative effect on the CYP11A- and StAR protein-gene expression in the early phase of ACTH-mediated steroidogenesis. To further explore the mechanisms underlying this phenomenon, we examined intracellular distribution of the green fluorescence protein (GFP)-tagged SIK. When GFP-SIK was introduced into HeLa cells, the fluorescent signals were detected in the nucleus. In Y-1 cells GFP-SIK was detected both in the nucleus and cytosol, and the signal in the former moved to the latter after ACTH-treatment. The nuclear/cytosol re-distribution of GFP-SIK was also observed in forskolin- or 8-Br-cAMP-treated Y-1 cells, but not in Kin-7 cells. These results suggest that the intracellular re-distribution of SIK in Y-1 cells may depend on the cAMP/PKA signaling pathway and has an important regulatory role in the ACTH-mediated steroidogenic gene expression.

Adrenal Cortex↗
PubMed1999

Cloning of a novel kinase (SIK) of the SNF1/AMPK family from high salt diet-treated rat adrenal.

PCR-coupled cDNA subtraction hybridization was adapted to identify the genes expressed in the adrenocortical tissues from high salt diet-treated rat. A novel cDNA clone, termed salt-inducible kinase (SIK), encoding a polypeptide (776 amino acids) with significant similarity to protein serine/ threonine kinases in the SNF1/AMPK family was isolated. An in vitro kinase assay demonstrated that SIK protein had autophosphorylation activity. Northern blot revealed that SIK mRNA levels were markedly augmented by ACTH treatment both in rat adrenal glands and in Y1 cells. SIK may play an important role in the regulation of adrenocortical functions in response to high plasma salt and ACTH stimulation.

AMP-Activated Protein Kinase Kinases↗
PubMed1998

Structure/function relationship of CYP11B1 associated with Dahl's salt-resistant rats--expression of rat CYP11B1 and CYP11B2 in Escherichia coli.

Dahl's salt-resistant normotensive rats (DR rats) have been previously reported to express cytochrome P-450 (CYP11B1) containing five missense mutations [Matsukawa, N., Nonaka, Y., Higaki, J., Nagano, M., Mikami H., Ogihara, T. & Okamoto, M. (1993) J. Biol. Chem. 268, 9117-9121]. To investigate structure-function relationships of CYP11B, wild-type rat CYP11B1 and CYP11B2 and DR-CYP11B1 (mutant CYP11B1 in Dahl's salt-resistant rats) have been successfully expressed in Escherichia coli. Steroid 11beta-hydroxylase (11beta-OHase) activity observed with DR-CYP11B1 was similar to that of wild-type CYP11B1, while 18-hydroxylase (18-OHase) activity of DR-CYP11B1 was lower than that of wild-type CYP11B1. Mutant CYP11B1s containing a single or a double amino acid substitution associated with DR-CYP11B1 have been also expressed in E. coli to investigate effects of the substitutions on enzymatic activity. Each of the single mutant enzymes showed lower 18-OHase activity than wild-type CYP11B1, but not as low as DR-CYP11B1. A double mutant CYP11B1 with V381L and I384L showed 18-OHase activity at a similar low level to that of DR-CYP11B1. The 19-hydroxylation (19-OHase) activity of DR-CYP11B1 was about one-third of that of the wild-type enzyme and this low activity appeared due to the V443M mutation. These results suggest that three of five amino acid substitutions present in DR-CYP11B1 account for the decreased 18-OHase and 19-OHase activities. A decrease in these enzyme activities may be responsible for the normotension of the DR rats when fed a high-salt diet.

Amino Acid Sequence↗
PubMed1998

Identification of functional domains of rat intestinal phospholipase B/lipase. Its cDNA cloning, expression, and tissue distribution.

A cDNA encoding a rat intestinal Ca(2+)-independent phospholipase B/lipase (PLB/LIP) was cloned from an ileac mucosa cDNA library using a probe amplified by polymerase chain reaction based on the purified enzyme's sequence. PLB/LIP consists of an NH2-terminal signal peptide, four tandem repeats of about 350 amino acids each, and a hydrophobic domain near the COOH terminus. The enzyme purified previously was found to be derived from the second repeat part. To examine the function of each domain, the full-length PLB/LIP, individual repeats, and a protein lacking the COOH-terminal hydrophobic stretch were expressed in COS-7 cells. The results showed that the second repeat, but not the other repeats, had all the activities (phospholipase A2, lysophospholipase, and lipase) found in the purified natural and expressed full-length enzymes, suggesting repeat 2 is a catalytic domain. The full-length enzyme was mainly present in membrane fractions and efficiently solubilized by treatment with 1% Triton X-100, but not with phosphatidylinositol-specific phospholipase C. Deletion of the COOH-terminal hydrophobic stretch caused the secretion of > 90% of synthesized PLB/LIP into culture media. These results suggest the hydrophobic domain is not replaced by a glycosylphosphatidylinositol anchor but serves as a membrane anchor directly. A message of the full-length PLB/LIP was abundantly expressed in the ileum and also, in a smaller, but significant amount, in the esophagus and testis. Immunohistochemistry showed that PLB/LIP is localized in brush border membranes of the absorptive cells, Paneth cells, and acrosomes of spermatid, suggesting its roles related and unrelated to intestinal digestion.

Amino Acid Sequence↗
PubMed1998

Cloning of a membrane-spanning protein with epidermal growth factor-like repeat motifs from adrenal glomerulosa cells.

The three zones of adrenal cortex are thought to arise from a single multipotential stem cell, but the mechanisms underlying the zonal differentiation during embryonic development of adrenal cortex are poorly understood. Employing subtraction cloning strategy, we isolated three distinct clones that were specifically expressed in the rat glomerulosa zone. One clone, named zona glomerulosa specific clone, encoded a membrane-spanning protein with a signal peptide at the N-terminus, six epidermal growth factor-like repeat motifs, and a transmembrane domain near the C-terminus. It was identified as a rat homolog of preadipocyte factor-1 (Pref-1), a factor involved in maintaining the undifferentiated status of preadipocyte. Immunohistochemical studies confirmed the presence of Pref-1 protein in the glomerulosa zone. Detailed examination revealed that the zone is divided into two layers; the first is a few-cells-thick layer present underneath the capsule (expressing both Pref-1 protein and aldosterone synthase cytochrome P450), and the second layer is beneath the first (containing Pref-1 protein but not aldosterone synthase). Moreover, another cell layer was found beneath the second layer and above the fasciculata zone, whose cells contained no Pref-1 protein, aldosterone synthase, or 11beta-hydroxylase. These findings suggest that a recently reported aldosterone synthase- and 11beta-hydroxylase-less cell layer between the two zones is composed of two kinds of cell: Pref-1 protein-positive and -negative cells. The level of Pref-1 message in the adrenal glands of animals having various pituitary-adrenal axis activities, as well as various plasma salt concentrations, correlated with the total number of glomerulosa cells. However, the specific content of Pref-1 message in a cell was fairly constant. When the adrenal gland was surgically enucleated and the remaining capsule regenerated, the level of Pref-1 transcript was significantly suppressed at the early phase. At this phase, only a minor population of the cortical cells expressed Pref-1 protein, most of these cells already expressing a fasciculata/reticularis-specific marker, inner zone antigen. These findings suggest that the capsular cells, mostly composed of the glomerulosa cells, may have potential for differentiating into other zones' cells, and the down-regulation of Pref-1 expression may be an important step in the adrenal zonal differentiation.

Adrenal Glands↗
PubMed1997

Polyadenylation-mediated translational regulation of maternal P450(11beta) mRNA in frog oocytes.

Northern blot analysis of bullfrog tissues using a cDNA probe of cytochrome P450(11beta) showed that a large amount of message was present in the ovary as well as in the adrenal tissue. Two kinds of mRNA of different sizes were found in the ovary. Sequence determination of the two cDNAs and analysis by reverse-transcription polymerase chain reaction indicated that the protein encoded by the larger mRNA was identical to the adrenal enzyme, while the protein encoded by the smaller had a truncated sequence lacking an extension peptide necessary for the protein transport to the mitochondria. The mRNAs were present in the oocytes but not in the follicular cells, and their content in an oocyte varied little during its maturation. Immunoblot analyses of the mitochondrial fraction of oocytes failed to demonstrate the presence of P450(11beta) protein. In contrast the eggs were found to contain a large amount of enzymatically active protein. Interestingly the mRNA has a cis-element called cytoplasmic polyadenylation element at its 3' untranslated region. When poly(A) tails of the message prepared from eggs and oocytes were examined by RNase H digestion or reverse-transcription polymerase chain reaction, those of eggs were about 150 nucleotides longer than those of oocytes. These results suggest that translation of the message is stimulated during the oocyte maturation as a result of enhanced polyadenylation at its 3'-end. Finally a finding is presented that progesterone was converted to 11beta-hydroxyprogesterone by the frog P450(11beta), implying that the enzyme expressed in eggs may control a level of progesterone which is needed to initiate the oocyte maturation.

Animals↗
PubMed1997

Zona glomerulosa-specific factor: cloning and function.

The rat adrenal cortex is composed of three zones: the zona glomerulosa, the zona fasciculata, and the zona reticularis. Several investigators have claimed the presence of a zona intermedia between the zonae glomerulosa and fasciculata. The cells of zona glomerulosa, a few layers of cells just beneath the adrenal capsule, synthesize and secrete aldosterone, whereas those of zonae fasciculata and reticularis secrete glucocorticoids and androgens, respectively. The function of the cells in zona intermedia is unclear, because they express neither aldosterone synthase nor 11 beta-hydroxylase. To investigate the mechanism underlying the zonal differentiation of adrenocortical steroidogenesis, attempts have been made to isolate and characterize zone-specifically expressed proteins such as steroidogenic enzymes and putative regulatory factors. Having subtracted the mRNAs present in the decapsulated adrenal gland from those in the adrenal capsule, we successfully isolated three distinct clones, each specifically expressed in the zona glomerulosa. One clone encoded a protein named zona glomerulosa-specific factor (ZOG), which had a putative signal peptide at the N-terminus, six tandem epidermal growth factor (EGF)-like repeats, and a transmembrane domain in the central portion and a short cytosolic stretch at the C-terminus. Immunohistochemical studies using the antibody raised against ZOG confirmed the presence of the protein in all layers of cells in the zona glomerulosa. In contrast, cells possessing aldosterone synthase were present only in the periphery of zona glomerulosa, just beneath the capsule. These findings suggest that there are at least two kinds of zona glomerulosa cells in the rat adrenal cortex, one expressing aldosterone synthase as well as ZOG, and another expressing only ZOG. The cells in the zona intermedia did not express ZOG, aldosterone synthase, or 11 beta-hydroxylase, but did express Ad4BP. ZOG was not detected in zonae fasciculata and reticularis where 11 beta-hydroxylase was present.

Adrenal Cortex↗
PubMed1997

Lipopolysaccharide and interleukin-1beta augmented histidine decarboxylase activity in cultured cells of the rat embryonic brain.

We investigated the effect of lipopolysaccharide (LPS) and various inflammatory cytokines on the histidine decarboxylase (HDC) activity in cultured cells of the rat embryonic brain. Histaminergic neuronal cell bodies were supposed to exist in cultured cells of the diencephalon but not in those of the cortex. The HDC activity was elevated by adding LPS and interleukin-1 beta (IL-1beta) but not by tumor necrosis factor-alpha (TNF-alpha) and IL-6 to the mixed primary cultures of diencephalon. In the adherent cell fraction of the cultured diencephalon cells, HDC activity was also enhanced by LPS and IL-1beta. In a similar manner, LPS augmented HDC activity in the mixed primary culture of cerebral cortical cells and in its adherent cell fraction. The effects of IL-1beta but not LPS in the mixed primary culture of diencephalon were canceled by a prior exposure to cytosine-beta-D-arabinofuranoside. The changes in HDC activity after exposure to LPS for 12 h were not accompanied by increased mRNA levels. In these cell cultures, mast cells were not detected by Alcian Blue staining. These results indicated the presence of the third type of HDC-bearing cell besides neurons and mast cells in the brain. The increase of HDC activity by IL-1beta might be due to cell proliferation.

Animals↗
PubMed1996

Absent myocardial I-123 BMIPP uptake in a family.

A 72-year-old woman with hypertension showed no sign of myocardial accumulation of 123I-BMIPP, and 201Tl and 123I-MIBG scintigraphy demonstrated normal findings. Electrocardiography showed left axis deviation with inverted T waves in leads I, aVL, V2-6 and QT prolongation. Coronary arteriography, two dimensional echo cardiography and laboratory data showed no abnormality. Her 66-year-old sister with non-insulin-dependent diabetes mellitus also had no myocardial BMIPP uptake, but had normal 201Tl finding. ECG and chest film findings were normal. Laboratory data indicated slightly high fasted blood glucose, triglyceride and total cholesterol. Four sons of a 72-year-old woman also underwent BMIPP scintigraphy. No BMIPP uptake was also observed in her 2nd son (49 years old) and his electrocardiogram showed QT prolongation. Since these rare findings indicating no myocardial BMIPP uptake were seen in a family, we suspected that a hereditary myocardial metabolic abnormality accounted for them.

3-Iodobenzylguanidine↗
PubMed1996

Cytochrome P450(11 beta): ectopic expression in oocyte and its physiological implication.

Cytochrome P450(11 beta) (steroid 11 beta-hydroxylase) catalyzes an essential step for biosynthesis of glucocorticoid as well as mineralocorticoid, and therefore is believed to exist specifically in the adrenocortical mitochondria. We previously isolated a complementary DNA clone encoding this enzyme from bullfrog (Rana catesbeiana) adrenal tissues and characterized the enzyme expressed in COS cells. To explore the tissue distribution of the enzyme we performed Northern blot analysis. Unexpectedly we found that a large amount of the mRNA exists in the ovary as well as the adrenal gland. It was present in oocytes, but not in follicular cells. The P450 protein was not found during early stages of oocyte development, and at the final stage of maturation the message appeared to be translated. Evidence was obtained that the stage-dependent translation of the mRNA was due to the regulated polyadenylation at its 3'-end. In oocytes of various organisms several maternal mRNAs are known to add poly(A) tails in the cytoplasm during the progesterone-induced maturation.

Adrenal Glands↗