Endocrine Modification of the Developmental Formation of Ornithine Aminotransferase in Rat Tissues

The direction and capacity for the metabolism of delta1-pyrroline-5-carboxylate in a number of rat tissues ere investigated by measuring the activities of delta1-pyrroline-5-carboxylate reductase, delta1-pyrroline-5-carboxylate dehydrogenase and proline oxidase. Each of these enzymes catalyzed unidirectional reactions in which delta1-pyrroline-5-carboxylate was either the substrate or product. Delta1-Pyrroline-5-carboxylate reductase activities that were much higher than any previously reported were obtained by avoiding its inactivation in the cold. delta1-Pyrroline-5-carboxylate dehydrogenase, previously said to act on both D- and L-isomers of delta1-pyrroline-5-carboxylate, acted only on the L-isomer. Proline oxidase could not be measured in two adult tissues, in which an inhibitor appeared after birth. The activity of delta1-pyrroline-5-carboxylate reductase significantly paralleled that of ornithine aminotransferase in 23 tissues, showing a widespread potential for proline synthesis from ornithine. An independently distributed potential in fewer tissues for proline degradation to alpha-oxoglutarate was shown by the significantly similar tissue distributions of proline oxidase. Delta1-pyrroline-5-carboxylate dehydrogenase and glutamate dehydrogenase. Reverse metabolism of glutamate or proline to ornithine would be atypical in rat tissues with these distributions of unidirectional enzyme reactions.

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Immunohistochemical localization of ornithine aminotransferase in normal rat tissues by Fab'-horseradish peroxidase conjugates.

Journal of Histochemistry & Cytochemistry ◽

10.1177/34.11.3534076 ◽

1986 ◽

Vol 34 (11) ◽

pp. 1385-1388 ◽

Cited By ~ 8

Author(s):

M Kasahara ◽

T Matsuzawa ◽

M Kokubo ◽

Y Gushiken ◽

K Tashiro ◽

...

Keyword(s):

Epithelial Cells ◽

Horseradish Peroxidase ◽

Pigment Epithelium ◽

Immunohistochemical Localization ◽

Rat Tissues ◽

Immunoperoxidase Method ◽

Ornithine Aminotransferase ◽

Inner Mitochondrial Membrane ◽

Specific Distribution ◽

Normal Rat

Immunohistochemical localization of ornithine aminotransferase (L-ornithine: 2-oxo-acid aminotransferase, EC 2.6.1.13), a mitochondrial enzyme whose hereditary absence induces gyrate atrophy of the choroid and retina, was elucidated by a direct immunoperoxidase method using Fab'-horseradish peroxidase conjugates. In immunodiffusion studies, the antibodies raised with the re-crystallized enzyme were highly specific to ornithine aminotransferase. To show localization of ornithine aminotransferase in normal rat tissues, clear immunohistochemical staining of this enzyme through the inner mitochondrial membrane in paraffin sections was achieved with Fab'-horseradish peroxidase conjugates. Strong immunoreactivity was present in cerebral neurons, hepatocytes, and epithelial cells of renal tubuli, gut mucous membranes, and ocular tissues. Specific distribution of ornithine aminotransferase was found in ependymal cell groups: namely, epithelial cells of the choroid plexus, pigmented and nonpigmented epithelial cells of the ciliary body. and Müller cells and pigment epithelium of the retina.

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High-resolution scanning electron microscopy (HRSEM) of mitochondria from various rat tissues

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102158 ◽

1988 ◽

Vol 46 ◽

pp. 14-15

Author(s):

P.J. Lea ◽

M.J. Hollenberg

Keyword(s):

Electron Microscopy ◽

Pigment Epithelium ◽

Retinal Pigment ◽

Rat Hepatocytes ◽

Three Dimensions ◽

Objective Lens ◽

Rat Tissues ◽

Thin Sections ◽

Reconstruction Methods ◽

Scanning Electron

Our current understanding of mitochondrial ultrastructure has been derived primarily from thin sections using transmission electron microscopy (TEM). This information has been extrapolated into three dimensions by artist's impressions (1) or serial sectioning techniques in combination with computer processing (2). The resolution of serial reconstruction methods is limited by section thickness whereas artist's impressions have obvious disadvantages.In contrast, the new techniques of HRSEM used in this study (3) offer the opportunity to view simultaneously both the internal and external structure of mitochondria directly in three dimensions and in detail.The tridimensional ultrastructure of mitochondria from rat hepatocytes, retinal (retinal pigment epithelium), renal (proximal convoluted tubule) and adrenal cortex cells were studied by HRSEM. The specimens were prepared by aldehyde-osmium fixation in combination with freeze cleavage followed by partial extraction of cytosol with a weak solution of osmium tetroxide (4). The specimens were examined with a Hitachi S-570 scanning electron microscope, resolution better than 30 nm, where the secondary electron detector is located in the column directly above the specimen inserted within the objective lens.

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The Demonstration of Human Prostatic Acid Phosphatase (Pap) With Phosphorylcholine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090427 ◽

1976 ◽

Vol 34 ◽

pp. 88-89

Author(s):

José A. Serrano ◽

Hannah L. Wasserkrug ◽

Anna A. Serrano ◽

Arnold M. Seligman

Keyword(s):

Acid Phosphatase ◽

Prostate Gland ◽

Prostatic Acid Phosphatase ◽

Human Prostate ◽

Rat Tissues ◽

Specific Substrate ◽

Acid Phosphatases ◽

Lysosomal Acid ◽

Cacodylate Buffer

As previously reported (1, 2) phosphorylcholine (PC) is a specific substrate for prostatatic acid phosphatase (PAP) as opposed to other acid phosphatases, e.g., lysosomal acid phosphatase. The specificity of PC for PAP is due to the pentavalent nitrogen in PC, a feature that renders PC resistant to hydrolysis by all other acid phosphatases. Detailed comparative cytochemical results in rat tissues are in press. This report deals with ultracytochemical results applying the method to normal and pathological human prostate gland.Fresh human prostate was obtained from 7 patients having transurethral resections or radical prostatectomies. The tissue was fixed in 3% glutaraldehyde- 0.1 M cacodylate buffer (pH 7.4) for 15 min, sectioned at 50 μm on a Sorvall TC-2 tissue sectioner, refixed for a total of 2 hr, and rinsed overnight in 0.1 M cacodylate buffer (pH 7.4)-7.5% sucrose.

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Fibrinolytic Activity of Lung and Spleen Extracts Observed in Conventional but not in Germ-Free Rats

Thrombosis and Haemostasis ◽

10.1055/s-0038-1666910 ◽

1979 ◽

Vol 42 (02) ◽

pp. 726-733 ◽

Cited By ~ 1

Author(s):

Utako Okamoto ◽

Jun-ichiro Yamamoto ◽

Yoko Nagamatsu ◽

Noboru Horie

Keyword(s):

Serine Protease ◽

Plasminogen Activator ◽

Fibrinolytic Activity ◽

Iodoacetic Acid ◽

Thrombin Inhibitor ◽

Rat Tissues ◽

Germ Free ◽

Neutral Ph ◽

Tissue Extracts

SummaryProtease-like activity which split plasminogen-free fibrin was demonstrated in 2 M KSCN extracts of the lung and spleen of conventional rats. The activity was virtually undetectable in tissue extracts from germ-free rats. The extracts from the conventional rat tissues split fibrin and fibrinogen remarkably at neutral pH, but not casein, when examined using fibrin, fibrinogen-agar and casein-agar plates. The fibrinolytic activity was inhibited by STI and DFP, indicating a serine protease nature. The activity was not inhibited by TLCK, t-AMCHA or dansyl-L-arginine-methylpiperidine amide (a selective synthetic thrombin inhibitor, OM189). It was neither activated nor inhibited by cysteine, KCN or iodoacetic acid. The results obtained indicate that the protease-like activity of the lung and spleen extracted with 2 M KSCN from conventional rats has properties which differ from those of trypsin, plasmin, plasminogen-activator, thrombin, and cathepsin A, B and C.

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Melatonin actions in the heart; more than a hormone

Melatonin Research ◽

10.32794/mr11250002 ◽

2018 ◽

Vol 1 (1) ◽

pp. 21-26 ◽

Cited By ~ 9

Author(s):

Darío Acuña-Castroviejo ◽

Maria T Noguiera-Navarro ◽

Russel J Reiter ◽

Germaine Escames

Keyword(s):

Cell Membranes ◽

Myocardial Cell ◽

Rat Tissues ◽

Dependent Manner ◽

Broad Distribution ◽

Multiple Organs ◽

High Doses ◽

Extrapineal Melatonin ◽

Dose Dependent ◽

Different Doses

Due to the broad distribution of extrapineal melatonin in multiple organs and tissues, we analyzed the presence and subcellular distribution of the indoleamine in the heart of rats. Groups of sham-operated and pinealectomized rats were sacrificed at different times along the day, and the melatonin content in myocardial cell membranes, cytosol, nuclei and mitochondria, were measured. Other groups of control animals were treated with different doses of melatonin to monitor its intracellular distribution. The results show that melatonin levels in the cell membrane, cytosol, nucleus, and mitochondria vary along the day, without showing a circadian rhythm. Pinealectomized animals trend to show higher values than sham-operated rats. Exogenous administration of melatonin yields its accumulation in a dose-dependent manner in all subcellular compartments analyzed, with maximal concentrations found in cell membranes at doses of 200 mg/kg bw melatonin. Interestingly, at dose of 40 mg/kg b.w, maximal concentration of melatonin was reached in the nucleus and mitochondrion. The results confirm previous data in other rat tissues including liver and brain, and support that melatonin is not uniformly distributed in the cell, whereas high doses of melatonin may be required for therapeutic purposes.

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