Biomedical subjects

N Endo

Publications and source records attributed to N Endo.

At least 109 records · Page 6Linked to original sources

PubMed1994

Racemization of Asp23 residue affects the aggregation properties of Alzheimer amyloid beta protein analogues.

The beta proteins in amyloid deposits of Alzheimer's disease have been found to be racemized and/or isomerized at their Asp residues (Roher, A. E., Lowenson, J. D., Clarke, S., Wolkow, C., Wang, R., Cotter, R. J., Reardon, I. M., Zurcher-Neely, H. A., Heinrikson, R. L., Ball, M. J., and Greenberg, B. D. (1993) J. Biol. Chem. 268, 3072-3083). To elucidate the effect of racemization on the aggregation properties of beta proteins, we synthesized four beta protein analogues in which D-Asp was substituted for L-Asp residues, i.e. normal beta 1-35, [D-Asp7]beta 1-35, [D-Asp23]beta 1-35, and [D-Asp7,D-Asp23]beta 1-35. The aggregation and fibril formation of the peptides were examined by means of spectrophotometry, sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE), and electron microscopy. Of the four peptides, [D-Asp23]beta 1-35 showed the earliest increase in turbidity and appearance of a smear in SDS-PAGE. This was followed by [D-Asp7,D-Asp23]beta 1-35 and normal beta 1-35. [D-Asp7]beta 1-35 was considerably delayed in showing these signs of aggregation. Corresponding with the increase in turbidity and the appearance of a smear in SDS-PAGE, fibril formation was observed in electron microscopy. These results reveal that the aggregation properties of beta 1-35 peptides are affected by racemization of their Asp residues depending on their position. Racemization at amino acid position 23 accelerated the peptide aggregation and fibril formation, while that at position 7 slowed down this reaction. This suggests that the site-specific racemization of beta protein may be involved in the amyloid fibril formation in Alzheimer's disease.

Alzheimer Disease↗

PubMed1994

Bone mineral density and bone histomorphometric assessments of postpregnancy osteoporosis: a report of five patients.

Reports of five young women who developed vertebral fractures associated with pregnancy and lactation are presented (Fig. 1). Ages ranged from 24 to 37 (mean 30) years. All five patients have osteoporosis with two to nine vertebral fractures at presentation postpartum. Bone mineral density (BMD) was measured by single-photon absorptiometry, quantitative computer tomography, and dual-energy X-ray absorptiometry. BMD of the trabecular bone was less than normal values and it remained apparently low even several years after pregnancy. Histological findings of bone biopsy identified the bone loss with increasing bone resorption. Our present findings suggest that postpregnancy osteoporosis affects mainly the trabecular bone site, and the patients might have low peak bone mass and poor reversibility probably due to a low rate of remodeling.

Absorptiometry, Photon↗

PubMed1994

The effect of hepatic portal dissection on the portal vein structure in biliary atresia.

Superior mesenteric portograms were performed on 30 patients with biliary atresia (BA) at the time of initial portoenterostomy in 20, and at the stoma closure operation in 10. A withered-branch-shaped irregularity of the intrahepatic portal vein (PV) and collateral vessels were seen in 2 of 11 patients with portal pressures (PP) of 200 to 300 mmH2O; in 1 of 2 patients with PPs of over 300 mmH2O at the initial operation; and in 3 jaundice-free patients with PPs of 285, 320, and 305 mmH2O, respectively, at the stoma closure operation. Collaterals were the only abnormalities seen in two additional jaundice-free patients with PPs of 370 and 183 mmH2O, respectively. No anatomic changes in the extrahepatic PV at the porta hepatis were found on the portograms of either group of patients. Thus, we conclude that portal dissection itself does not affect the PV structure anatomically, a finding which has important implications in determining whether or not portoenterostomy adversely affects potential liver transplantation.

Biliary Atresia↗

PubMed1994

[Analysis of complement-mediated phagocytosis in systemic lupus erythematosus model mice, NZB/W F1].

We have attempted to examine the cause of lowering phagocytic activity of phagocytes on clearance of bacteria in SLE patients. The experiments were performed in SLE model mice, NZB/WF1 female mice (BWF1). The ratio of the cells which phagocytized fluorescent microspheres and possessed Mac-1 on both peripheral blood leukocytes (PBL) and peritoneal macrophages (PMo) in BWF1 female mice was shown decreasing by using the flow cytometric method before the present of typical symptoms of SLE (under 25 weeks-old), i.e., the appearance of ANA and IgG deposits in glomeruli. In a period of showing the symptoms of SLE (over 25 weeks-old), the ratio of Mac-1 positive cells on PBL increased, but phagocytic function of these cells did not increase. On the other hand, on PMo, they decreased together in that period. Moreover, the phagocytosis of PMo in 15, 25, 35 weeks-old mice against fluorescent microspheres showed a significant increase (1.7 times) by replacing opsonin with normal (ddY) murine serum instead of BWF1 murine serum, and the phagocytosis of PMo treated with anti-Mac-1 antibody (M1/70) showed a significant inhibition (46%) against that of untreated PMo. These results indicate that lowering phagocytic activity of phagocytes on primary defence against microbial infections in SLE patients is due possibly to decrease of C3 activity in the serum rather than a decrease of positive percentage and function of Mac-1 on these cells.

Animals↗

PubMed1994

Induction of vascular endothelial growth factor expression by prostaglandin E2 and E1 in osteoblasts.

PGE1 and PGE2 are potent stimulators of bone formation. Osteogenesis is strongly dependent on angiogenesis. Vascular endothelial growth factor (VEFG), a secreted endothelial cell-specific mitogen, has been implicated in physiological and pathological angiogenesis. The aim of this study was to examine the possible role of VEGF in PG stimulation of bone formation. We found that in rat calvaria-derived osteoblast-enriched cells and in the osteoblastic RCT-3 cell line PGE2 and E1 increased VEGF mRNA and protein levels. The increased expression of VEGF mRNA produced by PGE2 was rapid (maximal at 1 h), transient (declined by 3 h), potentiated by cycloheximide, and abolished by actinomycin D. PGE2 had no effect on VEGF mRNA stability, suggesting transcriptional regulation of VEGF expression by PGF2. Rp-cAMP, a cAMP antagonist, suppressed VEGF mRNA induced by PGE2, indicating cAMP mediation. The upregulation of VEGF expression by PGE2 in the preosteoblastic RCT-1 cells was potentiated by treatment with retinoic acid, which induces the differentiation of these cells. The upregulation of VEGF mRNA by PGE2 was inhibited by dexamethasone treatment. In addition, Northern blot analysis showed that VEGF mRNA is expressed in adult rat tibia. In summary, we documented, for the first time, the expression of VEGF in osteoblasts and in bone tissue. Stimulation of VEGF expression by PGs and its suppression by glucocorticoids, which, respectively, stimulate and suppress bone formation, strongly implicate the involvement of VEGF in bone metabolism.

Alprostadil↗

PubMed1994

Racemization: its biological significance on neuropathogenesis of Alzheimer's disease.

Amyloid beta protein (A beta) in neuritic plaques of Alzheimer's disease has been found to be racemized and/or isomerized at their Asp residues. To elucidate the effect of racemization on the aggregation properties of A beta, we synthesized three kinds of A beta peptides in which D-Asp was substituted for L-Asp residues, i.e, normal A beta 1-40, [D-Asp7]A beta 1-40 and [D-Asp23]A beta 1-40. The aggregation and fibril formation of each peptide was examined by means of spectrofluorometry and electron microscopy. Of the three peptides, normal A beta showed the gradual increase of aggregation while [D-Asp7]A beta 1-40 and [D-Asp23] A beta 1-40 showed more enhanced aggregation at the final stage when the fibril formations were detected in all peptides solutions by electron microscopy. A comparative immunohistochemical study by anti-racemized A beta antibody and anti-A beta 1-42/43 antibody further showed the in vivo incorporation of D-Asp in senile plaques of Alzheimer's disease brains, which may be involved in plaque formation at the later stage than the deposition of the longer form of A beta (A beta 1-42/43). Taken together with the recent accumulated evidence on the aggregation mechanisms of A beta, the data presented here suggest that racemization may occur after the amyloid fibril formation but enhance the aggregation process by shifting the equilibrium of A beta from the soluble form to the insoluble form in Alzheimer's disease.

Alzheimer Disease↗

PubMed1994

[Determination of serum vitamin B12 and folic acid by non boil (new standard) radioassay].

On purpose to study the radioassay of serum vitamin B12 and folic acid using non boil methods in with these two vitamins were released from their endogenous binding proteins with alkaline denaturation and separated the bound vitamins from the free ones with the magnetic iron particles coated these vitamin binders (purified hog intrinsic factor and beta-lactoglobulin from cow milk) were evaluated on precision and accuracy, compared with boil radioassay. 1. The reproducibilities of non boil method were 4.5 +/- 2.5% on vit. B12 and 3.5 +/- 0.2% on folate (n = 10), respectively. 2. The recovery test of the two serum vitamins with the use of cyanocobalamin and pteroylglutamic acid (J.P.) were finely showed the rations of 95.2-99.0% for vit. B12 and 101.0-108.0% for folic acid. And that of folic acid use of 5-methyl-tetrahydro-pteroylglutamic acid was showed the ratios of 101.0-104.0%. The values of folic acid measured by this method were found slightly higher than non boil method using conventional standard. 3. The correlation coefficient between non boil method and boil method were 0.987 and regression equation was showed y = 0.97x + 73.59 for vit. B12 (n = 75) and r = 0.932, y = 1.02x-0.08 (n = 78) for folic acid. 4. Normal range of serum total vit. B12 concentration was 210-920 (484 +/- 160 pg/ml, n = 259) and that of folic acid was 2.5-9.2 (5.2 +/- 1.4 ng/ml, n = 257), as well as boil method. 5. Accordingly it was considered that non boil (new standard) method was excellent for estimation of vitamin B12 and folic acid clinical status.

Female↗

PubMed1993

Pattern of gene expression following rat tibial marrow ablation.

Following injury to bone marrow there is a phase of osteogenesis in which bone trabeculae replace the initial blood clot and fill the marrow cavity. The newly formed bone is subsequently fully resorbed by osteoclasts and normal bone marrow is restored. In this study we correlated the morphologic events with the pattern of gene expression that defines this sequence. Following marrow ablation, the trabecular bone volume in the affected section of the marrow cavity increased from control to 27% at day 6, declined to 18% at day 8, and eventually returned to control levels at day 14. Osteoblast number increased up to day 6 and declined substantially by day 8, but the number of osteoclasts peaked between days 8 and 10. Histologic analysis of alkaline phosphatase (AP) and tartrate-resistant acid phosphatase (TRAP) activity correlated with the observed cellular changes. Northern blot analysis of the levels of AP, osteocalcin (OC), and osteopontin (OP) mRNA shows a specific pattern of regulated gene expression, with AP mRNA maximal at day 6, OC mRNA very low until days 6-8, and OP mRNA expressed at very high levels throughout. In addition, procollagen alpha 1(I) and alpha 1(III) mRNAs show a regulated pattern of expression, with procollagen alpha 1(I) maximally expressed between days 4 and 10 and procollagen alpha 1(III) expressed at lower levels between days 4 and 6. The mRNA encoding insulin-like growth factor I (IGF-I) was found to be highly expressed between days 5 and 12; however, transforming growth factor beta 1 (TGF-beta 1) and TGF-beta 3 mRNA were only weakly expressed between days 4 and 10. These data demonstrate a temporal pattern of gene expression consistent with the observed morphologic profile, identify changes in growth factor mRNA that may be related to this repair process, and suggest that this is a suitable model for studying in vivo a synchronized sequence of bone formation and resorption at a well-defined anatomic site.

Alkaline Phosphatase↗

PubMed1993

Helicobacter pylori infection and chronic atrophic gastritis among Japanese blood donors: a cross-sectional study.

To evaluate an association between Helicobacter pylori (H. pylori) infection and chronic atrophic gastritis (CAG), an established precursor of gastric cancer, we performed a cross-sectional study using IgG antibody against H. pylori and pepsinogens of blood donors in four prefectures in Japan. Although a geographic correlation between the age-adjusted prevalence rates for H. pylori infection and those for CAG was not seen, the age-adjusted odds ratios (OR) of H. pylori infection for CAG were high in each area (around five for men and from four to 12.6 for women). The association between them weakened with advancing age; the ORs in the youngest age group (16-29 yrs) and in the oldest age group (50-64 yrs) were 12.5 and 2.8 for men, and 11.5 and 5.2 for women, respectively. These findings suggest that H. pylori infection is strongly associated with CAG, while there are some other factors interacting in the development of CAG. A prospective cohort study in which CAG and H. pylori infection are taken into account will be necessary to assess the risks of gastric cancer.

Adolescent↗

PubMed1993

Correlation between the prevalence of gastritis and gastric cancer in Japan.

To verify the hypothesis that chronic atrophic gastritis (CAG) is a precancerous lesion for gastric cancer, we investigated the correlation between the prevalence rates for CAG determined by levels of serum pepsinogens (I and II) of randomly selected, healthy, blood donors and the mortality rates for gastric cancer among four prefectures (Akita, Iwate, Miyagi, and Okinawa) in Japan. The prevalence rates for CAG according to a criterion that the level of pepsinogen I is below 70 ng/ml and the pepsinogen I to pepsinogen II ratio is below 3.0, were the highest in Akita for both sexes (38.8 percent in males, 37.8 percent in females) and the lowest in Okinawa (13.9 percent in males, 12.3 percent in females), where mortality rates for gastric cancer are the highest and the lowest in Japan, respectively. The correlation between the prevalence rates for CAG and the standardized mortality ratios for gastric cancer among these four prefectures was statistically significant in males (r = 0.97, P = 0.03), but less significant in females (r = 0.92, P = 0.08). These data strongly support the hypothesis that CAG is a precancerous lesion. The limitations of our cross-sectional study and the advantages of measuring the levels of serum pepsinogens in epidemiologic studies and in mass-screening programs for gastric cancer are discussed.

Adolescent↗

PubMed1993

Immunoglobulin variable region sequences of two human monoclonal antibodies directed to an onco-developmental carbohydrate antigen, lactotetraosylceramide (LcOse4Cer).

A human monoclonal antibody, 11-50, was generated and was shown to recognize an onco-developmental carbohydrate antigen, LcOse4Cer. The isotype of this antibody was IgM, lambda, similar to the previously known human anti-LcOse4 antibodies, such as IgMWOO and HMST-1. We raised a murine anti-idiotypic antibody G3 (IgG1, kappa) against 11-50, and tested its reactivity towards the affinity purified human polyclonal anti-LcOse4 antibodies prepared from pooled human sera using a Gal beta 1-->3GlcNAc beta-immobilized column. The results indicated that at least a part of the human polyclonal anti-LcOse4 antibodies shared the G3 idiotype with 11-50. We further analyzed the sequence of variable regions of the two anti-LcOse4 antibodies, 11-50 and HMST-1. Sequence analysis of the heavy chain variable regions indicated that the VH regions of these two antibodies were highly homologous to each other (93.5% at the nucleic acid level), and these antibodies utilized the germline genes VH1.9III and hv3005f3 as the VH segments, which are closely related germline genes of the VHIII family. It was noted that these germline VH genes are frequently utilized in fetal B cells. The JH region of both antibodies was encoded by the JH4 gene. For the light chain, the V lambda segments of the two antibodies were 96.3% homologous to each other at the nucleic acid level. The V lambda segments of both antibodies showed the highest homology to the rearranged V lambda gene called V lambda II.DS among reported V lambda genes, while the exact germline V lambda genes encoding the two antibodies were not yet registered in available sequence databanks. The amino acid sequences of the J lambda segments of both antibodies were identical. These results indicate that the two human antibodies recognizing the onco-developmental carbohydrate antigen Lc4 are encoded by the same or very homologous germline genes.

Amino Acid Sequence↗

PubMed1993

Predictive value of screening tests for persistent hepatitis C virus infection evidenced by viraemia. Japanese experience.

In November 1989, Japanese Red Cross Blood Centres started screening for hepatitis C virus (HCV) with enzyme-linked immunosorbent assay (Elisa) for the C100-3 viral peptide as the first such nationwide programme in the world. Thereafter post-transfusion non-A non-B hepatitis (PTNANBH) was reduced by 61-80%, but this was not as complete a success as our programme to prevent post-transfusion hepatitis B by screening for high titer hepatitis B core antibody, which we began in the same period. In order to acquire more effective control of PTNANBH, the HCV core-related antigen (GOR, N14) and second-generation Elisa (Ortho2, Abbott2) and second-generation antigen agglutination (PA, PHA) tests have been employed. Among 16,500 donors in 11 blood centers, 365 were serologically positive by at least one of these tests. Among these, HCV RNA was detected in 138 units and the remaining 227 were HCV RNA negatives. The effectiveness of these serological tests to detect HCV RNA-positive status were analyzed. Passive haemagglutination and particle agglutination (PHA and PA) tests were highly effective to predict HCV viraemia among blood donors. Also, these tests can easily determine antibody titre. By either PHA or PA, all units with > or = 2(12) agglutination titre (120 and 122 units) were HCV RNA positive and all agglutination-positive units with serum alanine aminotransferase level higher than 35 Karmen units were HCV RNA positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine Transaminase↗

PubMed1993

Differential expression of insulin-like growth factor-I (IGF-I) and IGF-II messenger ribonucleic acid in growing rat bone.

Insulin-like growth factors (IGF-I and IGF-II) are among the most abundant growth factors found in bone. Although their local production has been implicated in growth and development, localization of the cells that express these proteins is not well documented. We have studied, by in situ hybridization, the temporal and spatial expression of IGF-I and IGF-II mRNA in rat long bones at different stages of postnatal bone development. In 2-day-old rats, IGF-II was highly expressed in cartilage and in the mesodermal structures that surround the bone. At later stages of bone development, the IGF-II signal decreased in intensity, but could still be detected in the growth plate of tibial bones at 3 and 5 weeks. At this stage, the IGF-II signal in the epiphyseal growth plate was unevenly distributed and was stronger in the periphery than in the center, where it was mainly concentrated in the germinal layer and in some, but not all, cartilage columns. IGF-I, on the other hand, was only faintly detected in the periosteum at the early cartilaginous stage of bone development. At later stages, IGF-I was strongly associated with regions of ossification in the trabecular bone of the metaphysis and epiphysis and along the endosteal and periosteal surfaces. Surprisingly, we did not detect at any time IGF-I mRNA in chondrocytes of the epiphyseal growth plate. These results suggest that in the rat, IGF-II plays a role in early development of bone and in the longitudinal growth of the epiphyseal plate. IGF-I is more closely associated with the osteogenic regions and does not replace the declining levels of IGF-II in the growth plate.

Aging↗

PubMed1993

Fluorometric assay of rat brain N-methyltransferase with 4-methylnicotinamide.

A fluorometric method for the assay of rat brain N-methyltransferase (NMT) has been developed using rat brain 9000 x g supernatant fluid as an enzyme preparation. The method is based on the enzyme reaction at pH 8.6 using 4-methylnicotinamide (4-MN) as the methyl acceptor substrate in the presence of cofactor S-adenosyl-L-methionine (AdoMet), and the fluorometric determination of the product 1,4-dimethylnicotinamide by means of its reaction with 4-methoxybenzaldehyde. The apparent Km values for 4-MN and AdoMet were 0.47 mM and 19 microM, respectively. The method was successfully applied to the studies of age- and sex-related differences of brain NMT activity in rats. The enzyme activity decreased gradually between 3 and 14 weeks of age whereas there were no differences between males and females in the levels of NMT activity.

Aging↗

PubMed1992

Enhancement of antigen-induced interleukin 4 and IgE production by specific IgG1 in murine lymphocytes.

Conalbumin (CA)-specific type 2 helper T cell (Th2) clone, D10G4.1 (D10) produces IL4 when stimulated with varying doses of TNP-CA in the presence of mitomycin C-treated C3H spleen cells or purified B cells as antigen-presenting cells (APC). The production of IL4 was assessed by bioassay and by expression of IL4 mRNA. IL4 production reached maximum at 100 micrograms/ml of TNP-CA, whereas 1 microgram/ml of the antigen induced less than 10% of the maximum level of IL4. This lower level of IL4 production was augmented to the maximum level when monoclonal anti-TNP IgG1 was added to the culture at 0.5-1 microgram/ml. Anti-TNP IgE, but not anti-TNP IgM, was also effective, though IgE was 1/10 as effective as IgG1. IgG1 with an irrelevant specificity and F(ab')2 of anti-TNP IgG1 did not show augmenting effects. Moreover, the enhancement by anti-TNP IgG1 was completely abolished by monoclonal antibody against murine Fc gamma RII, 2.4G2. These results suggest that a low dose of the antigen complexed with IgG1 is focused on APC by means of Fc gamma RII, processed, and presented efficiently to the Th2 clone. On the other hand, the co-culture of D10 with normal C3H B cells in the presence of 1-100 micrograms/ml TNP-CA resulted in polyclonal IgE production. Anti-TNP IgG1 markedly augmented the lower level of IgE production induced by a suboptimal dose of the antigen (1 microgram/ml). This augmentation was shown to be dependent on endogenous IL4 because the enhancement was abolished by monoclonal anti-IL4 (11B11).

Animals↗

PubMed1992

[Kinetics of the complement subcomponent C1q production of peritoneal macrophages in NZB/W F1 female mice].

To clarify the role of local production (exohepatic) of complement on primary host defense mechanisms against microbial infections in the host who decreased the amount of complement in serum, the kinetics of the complement production by the complement-producing cells in exohepatic tissue was examined by measuring the amount of C1q, subcomponent of the first complement component, in cultured supernatant of the monolayer of peritoneal macrophages (PM phi) collected from 5, 15, 35, and 48 weeks-old female mice of NZB/W F1 (B/W F1). The C1q production of PM phi in B/W F1 mice showed remarkable decrease at 15 weeks-old. After that, however, the C1q producibility of PM phi recovered gradually and, at mice 48 weeks old, the complement produced finally exceeded the amount observed in mice 5 weeks-old, contrariwise the C1q values in serum were significantly lowering in the same aged mice. The increased production of C1q of PM phi was observed in both 35 and 48 weeks-old mice, of which the value corresponded with increase of anti-nuclear antibody titer in serum and of the amount of protein in urine. On female mice of ddY (control), the amount of C1q production of PM phi in 5 weeks-old mice was two-fold higher than that of 5 weeks-old B/WF1 mice. But at 15 weeks, the production showed a 1/2 decrease in that of mice 5 weeks-old and the decreased values were kept to 35 weeks-old.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1992

Identification of a new member of the steroid hormone receptor superfamily that is activated by a peroxisome proliferator and fatty acids.

We have identified a novel member of the steroid hormone receptor superfamily by cDNA cloning from a human osteosarcoma SAOS-2/B10 cell library. Sequence analysis predicts a protein of 441 amino acids, which includes the conserved amino acid residues characteristic of the DNA- and ligand-binding domains of nuclear receptors. Amino acid sequence alignment and transcriptional activation experiments revealed that the new protein is closely related to the mouse peroxisome proliferator activated receptor. The overall homology is 62%, and the highest similarity is seen in the DNA- and ligand-binding domains, 86% and 71%, respectively. Northern blot analysis showed that in mature rats, the receptor is highly expressed in heart, kidney, and lung as a transcript of approximately 3500 nucleotides. In human cells, the size of the mRNA is approximately 4000 nucleotides. Transcription assays using hybrid receptors consisting of the ligand-binding domain of the new protein and the DNA-binding domain of the glucocorticoid receptor showed weak stimulation by the peroxisome proliferator activator WY14643, suggesting a relationship to that receptor. Similar stimulation was observed with arachidonic and oleic acid (100-250 microM).

Amino Acid Sequence↗

PubMed1992

Fluorometric assay of rat tissue N-methyltransferases with nicotinamide and four isomeric methylnicotinamides.

Nicotinamide (NA) and its four isomeric methyl analogs [2-, 4-, 5- and 6-methylnicotinamides (MNs)] were tested as substrates for nicotinamide N-methyltransferase (NNMT) and amine N-methyltransferase (ANMT) using rat liver, kidney, spleen and brain 9000 x g supernatant fluids as model enzyme preparations. The N-methylated products were determined fluorometrically by their reaction with acetophenone or 4-methoxybenzaldehyde to form fluorescent 2,7-naphthyridine derivatives, and the lower limits of the determination were 8-30 pmol/100 microliters. N-Methyltransferase activities were detected in the liver with NA, 4-MN and 5-MN, and in the brain and spleen with 4-MN. On this basis, 5-MN is considered to be a selective substrate for NNMT in addition to NA, which is a known methyl acceptor for this enzyme. Although 4-MN appears to serve as a methyl acceptor for both ANMT and NNMT, it seems to be essentially a selective substrate for brain ANMT because of the absence of NNMT in brain. The fluorometric methods used here are also very useful because of their simplicity, sensitivity and selectivity.

Animals↗