The Morphology of the Rat Kidney Following Folic Acid Administration

Author(s):  
Aline Byrnes ◽  
Elsa E. Ramos ◽  
Minoru Suzuki ◽  
E.D. Mayfield

Renal hypertrophy was induced in 100 g male rats by the injection of 250 mg folic acid (FA) dissolved in 0.3 M NaHCO3/kg body weight (i.v.). Preliminary studies of the biochemical alterations in ribonucleic acid (RNA) metabolism of the renal tissue have been reported recently (1). They are: RNA content and concentration, orotic acid-c14 incorporation into RNA and acid soluble nucleotide pool, intracellular localization of the newly synthesized RNA, and the specific activity of enzymes of the de novo pyrimidine biosynthesis pathway. The present report describes the light and electron microscopic observations in these animals. For light microscopy, kidney slices were fixed in formalin, embedded, sectioned, and stained with H & E and PAS.

2020 ◽  
Vol 31 (1) ◽  
pp. 635-649
Author(s):  
Angelo Harlan De Crescenzo ◽  
Alexios A Panoutsopoulos ◽  
Lyvin Tat ◽  
Zachary Schaaf ◽  
Shailaja Racherla ◽  
...  

Abstract Folate is an essential micronutrient required for both cellular proliferation through de novo nucleotide synthesis and epigenetic regulation of gene expression through methylation. This dual requirement places a particular demand on folate availability during pregnancy when both rapid cell generation and programmed differentiation of maternal, extraembryonic, and embryonic/fetal tissues are required. Accordingly, prenatal neurodevelopment is particularly susceptible to folate deficiency, which can predispose to neural tube defects, or when effective transport into the brain is impaired, cerebral folate deficiency. Consequently, adequate folate consumption, in the form of folic acid (FA) fortification and supplement use, is widely recommended and has led to a substantial increase in the amount of FA intake during pregnancy in some populations. Here, we show that either maternal folate deficiency or FA excess in mice results in disruptions in folate metabolism of the offspring, suggesting diversion of the folate cycle from methylation to DNA synthesis. Paradoxically, either intervention causes comparable neurodevelopmental changes by delaying prenatal cerebral cortical neurogenesis in favor of late-born neurons. These cytoarchitectural and biochemical alterations are accompanied by behavioral abnormalities in FA test groups compared with controls. Our findings point to overlooked potential neurodevelopmental risks associated with excessively high levels of prenatal FA intake.


1988 ◽  
Vol 252 (1) ◽  
pp. 127-136 ◽  
Author(s):  
G M Trakshel ◽  
M D Maines

We have developed chromatographic and mathematical protocols that allowed the high resolution of glutathione S-transferase (GST) subunits, and the identification of a previously unresolved GST monomer in rat kidney cytosol; the monomer was identified tentatively as subunit 6. Also, an aberrant form of GST 7-7 dimer appeared to be present in the kidney. This development was utilized to illustrate the response of rat kidney GST following cis-platinum treatment in vivo. Rat kidney cytosol was separated into three ‘affinity families’ of GST activity after elution from a GSH-agarose matrix. The affinity peaks were characterized by quantitative differences in their subunit and dimeric compositions as determined by subsequent chromatography on a cation-exchange matrix and specific activity towards substrates. By use of these criteria, the major GST dimers of affinity peaks were tentatively identified. The major GST dimers in peak I were GST 1-1 and 1-2, in affinity peak II it was GST 2-2, and in peak III they were GST 3-3 and 7-7. GST 3-6 and/or 4-6, which have not been previously resolved in kidney cytosol, were also present in peak II. Alterations in the kidney cytosolic GST composition of male rats were detected subsequent to the administration of cis-platinum (7.0 mg/kg subcutaneously, 6 days). This treatment caused a pronounced alteration in the GST profile, and the pattern of alteration was markedly different from that reported for other chemicals in the kidney or in the liver. In general, the cellular contents of the GSTs of the Alpha and the Mu classes decreased and increased respectively. It is postulated that the decrease in the Alpha class of GSTs by cis-platinum treatment may be related to renal cortical damage and the loss of GSTs in the urine. The increase in the Mu class of GSTs could potentially stem from a lowered serum concentration of testosterone; the latter is a known effect of cis-platinum treatment.


1966 ◽  
Vol 53 (4) ◽  
pp. 655-662 ◽  
Author(s):  
István Kriskó ◽  
James B. Walker

ABSTRACT Arginine: glycine amidinotransferase is the first of two enzymes involved in creatine biosynthesis. The amidinotransferase specific activity (micromoles of hydroxyguanidine formed per hour per g wet weight of tissue) of kidney homogenates of mature male rats was about twice that of females of the same age, whereas activities were equal before puberty. Castration decreased the activity of males and increased that of females. The administration of testosterone propionate to young adult female rats resulted in a significant increase in enzyme activity. The same enzyme had previously been shown to be repressible by its end-product, creatine. Although there are numerous enzymes whose synthesis is known to be under hormonal control, amidinotransferase is the only mammalian enzyme described up to now on which there appears to operate both an end-product repression mechanism and a hormonal control on the de novo synthesis of the enzyme protein.


1971 ◽  
Vol 124 (2) ◽  
pp. 275-281 ◽  
Author(s):  
J. M. Lord ◽  
M. J. Merrett

1. Lowering of the concentration of carbon dioxide in air available to phototrophically growing Euglena cultures from 5% to the normal value (0.03%) resulted in an increased specific activity of glycollate oxidoreductase. 2. The effects of chloramphenicol and cycloheximide suggested that this increase in activity was due to enzyme synthesis de novo on cytoplasmic ribosomes. 3. The Km for glycollate oxidation by the enzyme in crude cell extracts was 3.0×10−3m. 4. Differential centrifugation established that glycollate oxidoreductase present in phototrophically grown Euglena is a particulate enzyme. The enzyme was partially solubilized by the non-ionic detergent Triton X-100. 5. Sucrose-density-gradient centrifugation achieved the separation of the particulate glycollate oxidoreductase from chloroplasts and mitochondria. 6. Glutamate–glyoxylate aminotransferase was associated with particulate glycollate oxidoreductase.


2018 ◽  
Vol 314 (4) ◽  
pp. E366-E376 ◽  
Author(s):  
Yue Jia ◽  
Jennifer K. Yee ◽  
Christina Wang ◽  
Liana Nikolaenko ◽  
Maruja Diaz-Arjonilla ◽  
...  

We previously showed that testosterone (T) deficiency enhanced high-fat/low-carbohydrate diet (HFD)-induced hepatic steatosis in rats independent of insulin resistance and that T replacement reduced hepatic macrovesicular fat accumulation and inflammation. The present report explores the mechanism of Tʼs protective effects on HFD-induced steatohepatitis. Adult male rats were randomized into four treatment groups for 15 wk: intact rats on regular chow diet or HFD, and castrated rats on HFD with or without T replacement. Fatty acid β-oxidation and de novo synthesis were not changed by castration and T replacement, but expression of lipid export proteins ApoB100 and microsomal triglyceride transfer protein (MTP) was suppressed by HFD in both intact and castrated rats but restored by T replacement. Macrovesicular lipid droplet-related proteins perilipin 1 and fat-specific protein 27 were increased by HFD in castrated rats and suppressed by T replacement. Higher activation/expression of ER stress proteins (PERK, IRE-1α, JNK, NF-κB, and CHOP) was demonstrated in castrated rats fed HFD compared with intact animals, and T replacement suppressed these changes. We conclude that 1) HFD leads to ApoB100/MTP suppression reducing export of lipids; 2) castration promotes progression to steatohepatitis through activation of the ER stress pathway and enhancement of macrovesicular droplet protein expression; and 3) testosterone suppresses ER stress, inhibits the formation of macrovesicular lipid droplets, promotes lipid export, and ameliorates steatohepatitis induced by HFD and castration.


Author(s):  
J. T. Stasny ◽  
R. C. Burns ◽  
R. W. F. Hardy

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.


Author(s):  
J. Chakraborty ◽  
A. P. Sinha Hikim ◽  
J. S. Jhunjhunwala

Although the presence of annulate lamellae was noted in many cell types, including the rat spermatogenic cells, this structure was never reported in the Sertoli cells of any rodent species. The present report is based on a part of our project on the effect of torsion of the spermatic cord to the contralateral testis. This paper describes for the first time, the fine structural details of the annulate lamellae in the Sertoli cells of damaged testis from guinea pigs.One side of the spermatic cord of each of six Hartly strain adult guinea pigs was surgically twisted (540°) under pentobarbital anesthesia (1). Four months after induction of torsion, animals were sacrificed, testes were excised and processed for the light and electron microscopic investigations. In the damaged testis, the majority of seminiferous tubule contained a layer of Sertoli cells with occasional spermatogonia (Fig. 1). Nuclei of these Sertoli cells were highly pleomorphic and contained small chromatinic clumps adjacent to the inner aspect of the nuclear envelope (Fig. 2).


Author(s):  
Venita F. Allison

In 1930, Moore, Hughes and Gallager reported that after castration seminal vesicle epithelial cell atrophy occurred and that cell regeneration could be achieved with daily injections of testis extract. Electron microscopic studies have confirmed those observations and have shown that testosterone injections restore the epithelium of the seminal vesicle in adult castrated male rats. Studies concerned with the metabolism of androgens point out that dihydrotestosterone stimulates cell proliferation and that other metabolites of testosterone probably influence secretory function in certain target cells.Although the influence of androgens on adult seminal vesicle epithelial cytology is well documented, little is known of the effect of androgen depletion and replacement on those cells in aging animals. The present study is concerned with the effect of castration and testosterone injection on the epithelium of the seminal vesicle of aging rats.


Author(s):  
D.R. Mattie ◽  
C.J. Hixson

Dimethylmethylphosphonate (DMMP) is a simple organophosphate used industrially as a flame retardant and to lower viscosity in polyester and epoxy resins. The military considered the use of DMMP as a nerve gas simulant. Since military use of DMMP involved exposure by inhalation, there was a need for a subchronic inhalation exposure to DMMP to fully investigate its toxic potential.Male Fischer-344 rats were exposed to 25 ppm or 250 ppm DMMP vapor on a continuous basis for 90 days. An equal number of control rats were sham-exposed. Following the 90-day continuous exposure period, 15 male rats were sacrificed from each group. Two rats from each group had the left kidney perfused for electron microscopic examination. The kidneys were perfused from a height of 150 cm water with 1% glutaraldehyde in Sorensen's 0.1M phosphate buffer pH 7.2. An additional kidney was taken from a rat in each group and fixed by immersion in 2.5% glutaraldehyde and 2% paraformaldehyde in 0.1M cacodylate buffer pH 7.4. A portion of the 9 kidneys collected for electron microscopy were processed into Epon 812. Thin sections, stained with uranyl acetate and lead citrate, were examined with a JEOL 100B Transmission Electron Microscope. Microvilli height was measured on photographs of the cells of proximal tubules. This data, along with morphologic features of the cells, allows the proximal convoluted tubules (PCT) to be identified as being S1, S2, or S3 segment PCT.


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