INFLUENCE OF GONADECTOMY, SEX HORMONES AND OTHER FACTORS, ON THE ACTIVITY OF CERTAIN GLYCOSIDASES IN THE RAT AND MOUSE

1959 ◽  
Vol 18 (2) ◽  
pp. 132-146 ◽  
Author(s):  
J. CONCHIE ◽  
JUNE FINDLAY

SUMMARY 1. The rise with age in the α-mannosidase, β-galactosidase, β-N-acetylglucosaminidase and βglucuronidase activities in the epididymis of mice and rats has been examined. Enzyme activities in both species reached a maximum at an age of 12–14 weeks. 2. Ovariectomy caused a considerable drop in all uterine enzyme activities in mice. Administration of oestrone to such mice restored the activities to intact levels. 3. Castration of both mice and rats greatly reduced the enzyme activities in the epididymis. Prolonged injection of testosterone raised all the activities, although not to intact levels. 4. Injections of menthol, chloroform and carbon tetrachloride caused changes in enzyme activity analogous to those already observed with β-glucuronidase, although there were quantitative differences in the response of each enzyme. 5. A study of the effects of partial hepatectomy, and to a lesser extent, injection of carbon tetrachloride on the glycosidase activities in ovariectomized mice provides evidence for the action of extraovarian oestrogen. 6. Changes in enzyme activities of the epididymis were seen after partial hepatectomy or injection of carbon tetrachloride in castrated male mice. 7. The qualitative behaviour of all four enzymes in response to the action of extrinsic agents suggests that they exert similar functions in the body, and that these may well lie in the field of mucopolysaccharide catabolism.

2019 ◽  
Vol 17 (4) ◽  
pp. 426-431
Author(s):  
Jin Xuezhu ◽  
Li Jitong ◽  
Nie Leigang ◽  
Xue Junlai

The main purpose of this study is to investigate the role of citrus leaf extract in carbon tetrachloride-induced hepatic injury and its potential molecular mechanism. Carbon tetrachloride was used to construct hepatic injury animal model. To this end, rats were randomly divided into 4 groups: control, carbon tetrachloride-treated, and two carbon tetrachloride + citrus leaf extract-treated groups. The results show that citrus leaf extract treatment significantly reversed the effects of carbon tetrachloride on the body weight changes and liver index. Besides, treatment with citrus leaf extract also reduced the levels of serum liver enzymes and oxidative stress in a dose-dependent manner. H&E staining and western blotting suggested that citrus leaf extract could repair liver histological damage by regulating AMPK and Nrf-2.


1998 ◽  
Vol 275 (4) ◽  
pp. G717-G722 ◽  
Author(s):  
Wisam F. Zakko ◽  
Carl L. Berg ◽  
John L. Gollan ◽  
Richard M. Green

Gluconeogenesis and glycogenolysis are essential hepatic functions required for glucose homeostasis. During the initial phase of hepatic regeneration, the immediate-early genes (IEG) are rapidly expressed, and the IEG RL-1 encodes for glucose-6-phosphatase (G-6- Pase). G-6- Pase is a microsomal enzyme essential for gluconeogenesis and glycogenolysis. This study employs a partial-hepatectomy model to examine the expression and activity of G-6- Pase. After partial hepatectomy, rat hepatic G-6- Pase gene expression is transcriptionally regulated, and mRNA levels are increased ≈30-fold. However, in contrast to this rapid gene induction, microsomal enzyme activity is unchanged after partial hepatectomy. Western blotting demonstrates that microsomal G-6- Pase protein expression is also unchanged after partial hepatectomy, and similar results are also noted in whole liver homogenate. Thus, despite marked induction in gene expression of the IEG G-6- Pase after partial hepatectomy, protein expression and enzyme activity remain unchanged. These data indicate that, although this hepatocyte IEG is transcriptionally regulated, the physiologically important level of regulation is posttranscriptional. This highlights the importance of correlating gene expression of IEG with protein expression and physiological function.


1966 ◽  
Vol 181 (1) ◽  
pp. 687-705 ◽  
Author(s):  
P. L. Barlow

It has previously been suggested that the reduction in cutting forces obtained by the presence of fluids such as CCl4 on the backface or free surface of the forming chip was due to diffusion of the fluid into the body of the chip in the region of the shear zone. In the present work, experiments with carbon tetrachloride tagged with carbon-14 and with carbon tetrachloride tagged with chlorine-36 were performed with the object of assessing the extent of diffusion of lubricants into the chip when present on the free surface only. The results obtained disprove former hypotheses and suggest that the reduced cutting force is due solely to chemical reaction at the surface of the chip. Confirmation of the sensitivity of the surface of the deforming shear zone to change in surface condition was obtained by removing metal from this region by an electropolishing technique during slow speed cutting. By varying the electropolishing conditions increased or decreased cutting forces could be obtained. It is proposed that the result both of chemical reaction at the surface and of surface removal is to reduce the strain-hardening rate of the metal undergoing shear by reducing the surface barrier to the flow of dislocations out of the metal. The association of the surface reaction of carbon tetrachloride with a change in the strain-hardening characteristics of the metal in the shear zone leads to a classification of the backface phenomenon as a Rehbinder effect and enables this effect to be more closely defined than was hitherto possible. Evidence is also presented which indicates that the backface effect does not contribute to the reduction in cutting forces during rakeface lubrication and is therefore unimportant in practice where flood lubrication of the cutting region invariably occurs.


2000 ◽  
Vol 351 (2) ◽  
pp. 439-447 ◽  
Author(s):  
Caroline A. MACKINTOSH ◽  
Anthony E. PEGG

Mutant Gy male mice, which have previously been described as having disruption of the phosphate-regulating Phex gene and a spermine synthase gene [Meyer, Henley, Meyer, Morgan, McDonald, Mills and Price (1998) Genomics, 48, 289–295; Lorenz, Francis, Gempel, Böddrich, Josten, Schmahl and Schmidt (1998) Hum. Mol. Genet. 7, 541–547], as well as mutant Hyp male mice, which have disruption of the Phex gene only, were examined along with their respective normal male littermates. Biochemical analyses of extracts of brains, hearts and livers of 5-week-old mice showed that Gy males lacked any significant spermine synthase activity as well as spermine content. Organs of Gy males had a higher spermidine content. This was caused not only by the lack of conversion of spermidine into spermine, but also because of compensatory increases in the activities of other polyamine biosynthetic enzymes. Gy males were half the body weight of their normal male littermates at weaning age. Hyp males, however, were no different in size when compared with their controls. High mortality of Gy males occurs by weaning age and this mortality was shown to be largely post-natal. Embryonic fibroblasts were isolated from Gy males and their normal male littermates and were similarly shown to lack any significant spermine synthase activity as well as spermine content. The lack of spermine, however, had no significant effect on the growth of immortalized fibroblasts or of primary fibroblast cultures. Similarly, there was no difference in the time of senescence of primary fibroblast cultures from Gy males compared with cultures derived from normal male littermates. However, the lack of spermine did increase the sensitivity of immortalized fibroblasts to killing by the chloroethylating agent 1,3-bis(2-chloroethyl)-N-nitrosourea. Therefore both the Gy male mice and derived embryonic fibroblasts provide valuable models to study the importance of spermine and spermine synthase, without the use of inhibitors which may have additional side effects.


1987 ◽  
Vol 35 (6) ◽  
pp. 657-662 ◽  
Author(s):  
J P Holt ◽  
E Rhe

Lactate dehydrogenase (LDH; EC 1.1.1.27), citrate synthase (CS; EC 4.1.3.7), and beta-hydroxyacyl-CoA-dehydrogenase (beta-OH-acyl-CoA-DH; EC 1.1.1.35) activities were determined in each of the three major cell types of rat uterus, i.e., epithelial, stromal, and smooth muscle, using quantitative microanalytical techniques. Adult ovariectomized rats were treated with 17-beta-estradiol to determine the time course and dose response (0.025-50 micrograms/300-g rat) effect of estrogen on enzyme activity of each type of uterine cell. The use of "oil well" and enzyme-cycling microtechniques to determine the time course and the dose responses of enzyme activity changes required microassays involving 1595 microdissected single cell specimens. Estradiol treatment increased epithelial LDH, CS and beta-OH-acyl-CoA-DH activity but had no effect on these enzymes in the stroma or in smooth muscle cells. The estradiol-stimulated peak enzyme activities on Day 4 in the intervention group are compared with those in the ovariectomized rat controls as follows: LDH, 44.5 +/- 3.5 vs 22.3 +/- 3.9; CS, 3.5 +/- 0.2 vs 1.5 +/- 0.6; beta-OH-acyl-CoA-H, 3.5 +/- 0.32 vs 2.2 +/- 0.2 (mean +/- standard deviation; mol/kg/hr). Stromal cell activities (LDH, 7.4 +/- 1.0; CS, 1.2 +/- 0.2; beta-OH-acyl-CoA-DH, 0.9 +/- 0.1) were significantly lower than epithelial cell levels and were similar to smooth muscle levels. Therefore, even in the ovariectomized animal epithelial cells have markedly higher metabolic activity compared with adjacent cells. The enzyme activities are expressed as moles of substrate reacting per kilogram of dry weight per hour. All three enzymes exhibited a 17-beta-estradiol-induced dose response between 0.025-0.15 micrograms/300-g rat. The three enzymes studied all had similar response patterns to estrogen. The effect of estradiol was restricted to epithelial cells, with enzyme activities increasing to maximal levels after approximately 96 hr of hormone treatment. This study therefore not only confirms the specific and differential metabolic responses of uterine cells to estradiol treatment, but clearly demonstrates that marked metabolic differences exist between epithelial cells and stromal or smooth muscle uterine cells.


2012 ◽  
Vol 518-523 ◽  
pp. 39-43
Author(s):  
Xiao Guang Zhao ◽  
Yuan Yuan Guan ◽  
Wen Yu Huang

In this paper, simulated experiments were performed in pots by using soil materials in different conditions of film remnant. Based on the research on soil microorganism quantity trends of soil enzyme activities were analyzed systematically: soil without film remnant, soil with film remnant for 5, 10, 15 and 20 years. By analyzing crop progress, the relationship with soil material was studied, in order to provide scientific basis for the variation laws between different conditions of film remnant and the activity of soil enzyme.


1972 ◽  
Vol 129 (3) ◽  
pp. 645-655 ◽  
Author(s):  
J. S. Heller ◽  
C. L. Villemez

A neutral-detergent-solubilized-enzyme preparation derived from Phaseolus aureus hypocotyls contains two types of glycosyltransferase activity. One, mannosyltransferase enzyme activity, utilizes GDP-α-d-mannose as the sugar nucleotide substrate. The other, glucosyltransferase enzyme activity, utilizes GDP-α-d-glucose as the sugar nucleotide substrate. The soluble enzyme preparation catalyses the formation of what appears to be a homopolysaccharide when either sugar nucleotide is the only substrate present. A β-(1→4)-linked mannan is the only polymeric product when only GDP-α-d-mannose is added. A β-(1→4)-linked glucan is the only polymeric product when only GDP-α-d-glucose is added. In the presence of both sugar nucleotides, however, a β-(1→4)-linked glucomannan is formed. There are indications that endogenous sugar donors may be present in the enzyme preparation. There appear to be only two glycosyltransferases in the enzyme preparation, each catalysing the transfer of a different sugar to the same type of acceptor molecule. The glucosyltransferase requires the continual production of mannose-containing acceptor molecules for maintenance of enzyme activity, and is thereby dependent upon the activity of the mannosyltransferase. The mannosyltransferase, on the other hand, does not require the continual production of glucose-containing acceptors for maintenance of enzyme activity, but is severely inhibited by GDP-α-P-glucose. These properties promote the synthesis of β-(1→4)-linked glucomannan rather than β-(1→4)-linked glucan plus β-(1→4)-linked mannan when both sugar nucleotide substrates are present.


Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Frederique B Yiannikouris ◽  
Genevieve Nguyen

Objectives: Recent studies demonstrated that the prorenin renin receptor (PRR) is present in adipose tissue. In adipose tissue stromal cells, PRR has the ability to bind renin and prorenin and contributes to the generation of angiotensinI (AngI). However, the contribution of adipocyte PRR to the generation of the vasoactive peptide, AngII and therefore to the regulation of blood pressure in physiological condition is unknown. The purpose of this study was to develop and characterize a new mouse model with adipocyte-specific PRR deficiency and define the role of adipose PRR in normal physiology. Methods and results: Female mice with 2 loxP sites flanking exon 2 of the PRR gene (floxed alleles, PRRfl/fl) were bred with aP2-Cre or with Adi-Cre male mice. Since PRR is located in the X chromosome, the male mice generated from the breeding were homozygotes for the deletion (PRRaP2 and PRRAdi). From the breeding, 5 PRRfl/fl, 2 PRRaP2 and 5 PRRAdi male mice were generated suggesting that the deletion of PRR in adipocyte was not lethal. Mice were fed on chow diet during 20 weeks. The body weight, the fat, lean mass and the blood pressure were quantified. Preliminary data suggest that the body weights (BW) were slightly decreased in PRRaP2 and PRRAdi compared to PRRfl/fl (PRRfl/fl: 29±1g; PRRaP2: 25±5g; PRRAdi: 28±1g). The slight reduction in BW was attributed to a reduction in fat mass (PRRfl/fl: 4.8±0.9g; PRRaP2: 3.8±1.8g; PRRAdi: 1.9±0.4g). Blood pressure was measured by plethysmography and by radiotelemetry. Preliminary data demonstrated that under physiological conditions, the SBP was not changed in PRRaP2 male mice compared to PRRfl/fl mice (plethysmography: PRRfl/fl: 108±1 mmHg; PRRaP2: 99±7 mmHg; radiotelemetry: PRRfl/fl: 129±2 mmHg; PRRaP2: 128±6 mmHg). The SBP of PRRAdi is currently under investigation. Conclusions: These results demonstrate the viability of mice with specific adipocyte deficiency of PRR. Future studies will define the effects of adipocyte PRR deficiency on obesity-induced hypertension.


Reproduction ◽  
2021 ◽  
Author(s):  
Marina Izvolskaia ◽  
Vasilina Ignatiuk ◽  
Ayshat Ismailova ◽  
Viktoria Sharova ◽  
Liudmila Zakharova

Sexual performance in adult male rats is highly sensitive to prenatal stress which can affect the functionality of the reproductive system and various brain structures involved in modulating sexual behavior. The immunomodulatory effect of mouse IgG on reproductive maturity in male offspring after LPS exposure in vivo and in vitro was studied. Prenatal IgG injection (20 µg / mouse) had a positive impact on the puberty of male mice whose mothers were exposed to LPS (100 µg / kg) on the 12th day of pregnancy. The number of Sertoli cells were increased, whereas the body weight and the number of symplastic spermatids were decreased in offspring as compared to LPS-treated animals. Besides, IgG had a positive effect on altered hormone levels: reduced estradiol level on the 5th and 14th postnatal days and increased testosterone level on the 30th postnatal day in blood that led to an increased number of mounting attempts in sexually mature males. The cAMP-dependent pathway may be involved in the regulation of the LPS-induced inflammation. IgG reduced the increased level of cAMP in mouse peritoneal macrophages activated by LPS in vitro. IgG is able to modulate inflammation processes, but its exposure time is important.


2021 ◽  
Vol 10 ◽  
Author(s):  
Yibing Bai ◽  
Jiani Yang ◽  
Ying Cui ◽  
Yuanfei Yao ◽  
Feng Wu ◽  
...  

Sirtuins (SIRTs) are members of the silent information regulator-2 family. They are a conserved family of nicotinamide adenine dinucleotide-dependent protein lysine deacylases. SIRTS are involved in intricate cellular processes. There are seven subtypes of SIRTs (1–7) in mammals. SIRT4 is located mainly in mitochondria and has various catalytic activities. These enzyme activities give it a diverse range of important biologic functions, such as energy metabolism, oxidative stress, and aging. Cancer is characterized as reprogramming of energy metabolism and redox imbalance, and SIRT4 can affect tumorigenesis. Here, we review the structure, localization, and enzyme activity of SIRT4 and its role in various neoplasms.


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