Absence of hepatic p-nitrophenol UDP-glucuronosyltransferase induction by spironolactone in male rats: possible involvement of testosterone

1992 ◽  
Vol 70 (11) ◽  
pp. 1502-1507 ◽  
Author(s):  
Viviana A. Catania ◽  
Marcelo G. Luquita ◽  
Enrique J. Sánchez Pozzi ◽  
Alejandro M. Ferri ◽  
Aldo D. Mottino

This study was performed to determine whether the lack of spironolactone induction of hepatic p-nitrophenol UDP-glucuronosyltransferase in male rats could be attributed to a presumed interaction between spironolactone and testosterone. The effect of spironolactone was evaluated in four experimental groups: normal females, normal males, castrated males, and castrated males that received testosterone. Enzyme activity was measured in native microsomes and in microsomes activated with UDP-N-acetylglucosamine or Triton X-100. When the nucleotide was included in the incubations, it was observed that enzyme activity in castrated male rats decreased to values approaching those obtained in normal females. Treatment of castrated animals with testosterone enhanced enzyme activity so that no significant difference existed between this group and normal males. This suggests that testosterone may act as an endogenous inducer of hepatic p-nitrophenol glucuronidation. It was also found that only females and castrated males showed an increase in enzyme activity in response to spironolactone treatment. Thus, the absence of an additive effect of endogenous or exogenous testosterone and spironolactone on UDP-glucuronosyltransferase activity suggests that these compounds could share a common induction mechanism, which appears to reach its maximal capacity in male rats. Possible explanations of this observation are discussed. From the analysis of enzyme activity in native and Triton X-100 activated microsomes, it can be postulated that spironolactone enzyme induction in female and castrated male rats could be attributed to an enhancement in the transferase synthesis rather than to an alteration of the membrane environment.Key words: UDP-glucuronosytransferase, spironolactone, enzyme induction, testosterone, p-nitrophenol.

1970 ◽  
Vol 117 (2) ◽  
pp. 319-324 ◽  
Author(s):  
G. J. Mulder

1. The detergent Triton X-100 activates UDP glucuronyltransferase from rat liver in vitro six- to seven-fold with p-nitrophenol as substrate. The enzyme activity when measured in the presence of Triton X-100 is increased significantly by pretreatment of male rats with phenobarbital for 4 days (90mg/kg each day intraperitoneally). If no Triton X-100 is applied in vitro such an increase could not be shown. In all further experiments the enzyme activity was measured after activation by Triton X-100. 2. The Km of the enzyme for the substrate p-nitrophenol does not change on phenobarbital pretreatment. 3. When the microsomal fraction from the liver of untreated rats is subfractionated on a sucrose density gradient, 47% of the enzyme activity is recovered in the rough-surfaced microsomal fraction, which also has a higher specific activity than the smooth-surfaced fraction. 4. Of the increase in activity after the phenobarbital pretreatment 50% occurs in the smooth-surfaced fraction, 19% in the rough-surfaced fraction and 31% in the fraction located between the smooth- and rough-surfaced microsomal fractions on the sucrose density gradient. 5. The latency of the enzyme in vitro, as shown by the effect of the detergent Triton X-100, is discussed in relation to the proposed heterogeneity of UDP glucuronyltransferase.


1971 ◽  
Vol 19 (3) ◽  
pp. 175-181 ◽  
Author(s):  
MASANDO HAYASHI

A simultaneous coupling azo-indoxyl method for the cytochemical demonstration of acid phosphatase activity using p-toluidine salt of 1-acetyl-3-indolyl phosphate is described. A satisfactory staining for the enzyme activity was obtained following incubation of formol-calcium-fixed frozen sections for 30 min at 25°C in a medium containing 1 mM each of the substrate and hexazonium pararosanilin and adjusted to pH 4.5-5.0 with acetate buffer. The distribution of acid phosphatase activity demonstrated by this method was identical with that obtained either by Gomori's technique using β-glycerophosphate as substrate or by the Barka and Anderson's naphthol AS-BI phosphate-hexazonium pararosanilin method in several tissues of male rats so far examined. However, the adrenal enzyme activity was most prominent in the medulla with 1-acetyl-3-indolyl phosphate and β-glycerophosphate but it was more marked in the cortex with naphthol AS-BI phosphate. An advantage of using 1-acetyl-3-indolyl phosphate as substrate is that the same compound can be used for comparing azo-indoxyl and lead-salt methods. Effects of phospholipase C and Triton X-100 on staining for acid phosphatase were tested by pretreating fixed rat liver and kidney sections with these agents and incubating them in the medium containing 1-acetyl-3-indolyl phosphate and either hexazonium pararosanilin or lead ions as a coupler. The pretreatment did not change discrete lysosomal staining, as seen in untreated controls, using pararosanilin as a coupler, but greatly modified the staining using lead ions. The results indicate that the preciseness of staining for acid phosphatase with lead-salt method is highly dependent on some lipid material which attracts lead in tissues and that appropriately devised azo dye or azo-indoxyl methods demonstrate enzyme sites more accurately than lead-salt method.


1982 ◽  
Vol 2 (11) ◽  
pp. 899-906 ◽  
Author(s):  
Harald Hettkamp ◽  
Ernst Bause ◽  
Günter Legler

Particulate membrane fractions from calf liver catalyze the release of glucose from GlcNAc2-Man9-Glc1–3-oligosaccharides. Maximal oligosaccharide-glucosidase activity was obtained at pH 6.2 and a detergent concentration of 0.5% Triton X-100. This activity could be distinguished from non-specific α-glucosidase activity on the basis of different pH-dependence and lack of activation by detergent. The relative rates for the hydrolysis of the Glc3-, Glc2-, and Glcl-oligosaccharide, estimated from the initial velocity, was 1: 12: 3. There is no significant difference in the enzyme activity towards free, peptide-bound, or lipid-linked oligosaccharide. Nojirimycin and l-deoxynojirimycin were strong inhibitors of microsomal oligosaccharide-glucosidases. Hydrolysis of GIc3-oligosaccharide was inhibited by 50% at concentrations of 0.16 mM and 2 μM, respectively. Hydrolysis of the Glc2- and Glc1-oligosaccharide was inhibited to a somewhat lower extent, suggesting the presence of at least two glucosidases, one acting on Glc3- and one acting on Glc1- and Glc2-oligosaccharide.


2018 ◽  
Vol 15 (7) ◽  
pp. 610-617 ◽  
Author(s):  
Huifeng Zhang ◽  
Dan Liu ◽  
Huanhuan Huang ◽  
Yujia Zhao ◽  
Hui Zhou

Background: β-amyloid (Aβ) accumulates abnormally to senile plaque which is the initiator of Alzheimer's disease (AD). As one of the Aβ-degrading enzymes, Insulin-degrading enzyme (IDE) remains controversial for its protein level and activity in Alzheimer's brain. Methods: The electronic databases PubMed, EMBASE, The Cochrane Library, OVID and Sinomed were systemically searched up to Sep. 20th, 2017. And the published case-control or cohort studies were retrieved to perform the meta-analysis. Results: Seven studies for IDE protein level (AD cases = 293; controls = 126), three for mRNA level (AD cases = 138; controls = 81), and three for enzyme activity (AD cases = 123; controls = 75) were pooling together. The IDE protein level was significantly lower in AD cases than in controls (SMD = - 0.47, 95% CI [-0.69, -0.24], p < 0.001), but IDE mRNA and enzyme activity had no significant difference (SMD = 0.02, 95% CI [-0.40, 0.43] and SMD = 0.06, 95% CI [-0.41, 0.53] respectively). Subgroup analyses found that IDE protein level was decreased in both cortex and hippocampus of AD cases (SMD = -0.43, 95% CI [-0.71, -0.16], p = 0.002 and SMD = -0.53, 95% CI [-0.91, -0.15], p = 0.006 respectively). However, IDE mRNA was higher in cortex of AD cases (SMD = 0.71, 95% CI [0.14, 1.29], p = 0.01), not in hippocampus (SMD = -0.26, 95% CI [-0.58, 0.06]). Conclusions: Our results indicate that AD patients may have lower IDE protease level. Further relevant studies are still needed to verify whether IDE is one of the factors affecting Aβ abnormal accumulation and throw new insights for AD detection or therapy.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1569
Author(s):  
Tomislav Šušnjar ◽  
Ivana Kuzmić Prusac ◽  
Ivan Švagelj ◽  
Anđela Jurišić ◽  
Tomislav Šušnjar ◽  
...  

Background: The aim of this study was to compare consequences in single and triple testicular biopsy by biopty gun in pubertal rats using histological and immunohistochemical analysis. Methods: Thirty-two Sprague-Dawley male rats were used as the experimental model. The rats were randomly divided into three study groups. The rats from the first group (n = 12) received a single-biopsy of upper pole of the left testis, while the rats from the second group (n = 10) received triple-biopsy of upper and lower poles and lateral surface of left testis. The third group (n = 10) was a control group. On the eightieth day after the biopsy in all rats bilateral orchiectomy and funiculectomy were performed to obtain testicular tissue and sperm for analysis. The consequences of the puncture were observed by pathohistology, immunohistochemistry and semen analysis. Results: The results of the study showed lower percentage of sperm count (14.5 mill/mL vs. 16 mill/mL, p = 0.130), sperm motility (24.6% vs. 32.7%, p > 0.05), abnormal sperm (30% vs. 27%, p > 0.05), atrophic tubules (21% vs. 6%, p < 0.001), volume (1.7 mL vs. 2.28 mL, p < 0.01) and apoptotic index (1.56 vs. 1.19, p = 0.650) in the testes with a triple-biopsy compared to the testes with a single-biopsy. Semen analysis showed a borderline significant difference between the group with triple-biopsy where sperm count was lower than it in the control group (14.5 mill/mL vs. 17.5 mill/mL, p = 0.05). A single-biopsy has little effect on the testis, especially on overall fertility. A triple-biopsy showed higher degree of the testicular damage but without a significant impact on overall fertility. Semen analysis showed that single- and triple-biopsies did not have a significant effect on sperm count, motility and morphology. Conclusion: Biopty gun procedure is a cheap, simple and reliable method for testicular biopsy in rats without a significant effect on sperm count, motility and morphology.


1983 ◽  
Vol 64 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Maurizio Muraca ◽  
Jan De Groote ◽  
Johan Fevery

1. Hepatic bilirubin UDP-glucuronosyltransferase activity was higher in female than in male rats; gonadectomy decreased enzyme activity in females and increased it in males. This sex difference in bilirubin conjugation was further used to evaluate the effect of differences in conjugation on the maximal biliary excretion of bilirubin in the non-anaesthetized rat. 2. After infusion of bilirubin, the maximal biliary excretory rate (Tm) and maximal concentration of bilirubin in bile were respectively 70% and 40% higher in female than in male rats; these values were decreased in females after ovariectomy and increased in males after orchiectomy. A linear relationship was found (r = 0.86; P < 0.001) between bilirubin Tm and hepatic bilirubin UDP-glucuronosyltransferase activity in the four groups of rats, suggesting that conjugation was the rate-limiting step for the maximal hepatic transport of bilirubin. 3. At the end of bilirubin infusion, bilirubin conjugates in serum, determined by alkaline methanolysis and high-performance liquid chromatography, ranged from 0.5 to 1.4% of total bilirubin. Therefore no significant reflux of conjugated bilirubin occurred during saturation of the hepatic transport of the pigment, once more suggesting that the secretory step was not rate-limiting. 4. The composition of bilirubin conjugates in bile was similar in the four groups of rats, despite significant differences in transferase activity. This suggests that the relative proportion of bilirubin mono- and di-conjugates in bile is affected by factors other than transferase activity alone. Relatively more monoconjugates were excreted under the bilirubin load than in basal conditions.


1985 ◽  
Vol 227 (2) ◽  
pp. 405-412 ◽  
Author(s):  
P W Cheng ◽  
W E Wingert ◽  
M R Little ◽  
R Wei

We have characterized a bovine tracheal mucin beta-6-N-acetylglucosaminyltransferase that catalyses the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to the C-6 of the N-acetylgalactosamine residue of galactosyl-β 1→3-N-acetylgalactosamine. Optimal enzyme activity was obtained between pH 7.5-8.5, at 5mM-MnCl2, and at 0.06-0.08% (v/v) Triton X-100 (or Nonidet P-40), or 0.5-5.0% (v/v) Tween 20. Ba2+, Mg2+ and Ca2+ could partially replace Mn2+, but Co2+, Fe2+, Cd2+ and Zn2+ could not. Sodium dodecyl sulphate, cetylpyridinium chloride, sodium deoxycholate, octyl beta-D-glucoside, digitonin and alkyl alcohols were less effective in enhancing enzyme activity, and dimethyl sulphoxide was ineffective. The apparent Michaelis constants were 1.25 mM for UDP-N-acetylglucosamine, 0.94-3.34 mM for freezing-point-depressing glycoprotein and 0.19 mM for periodate-treated blood-group-A porcine submaxillary mucin. Asialo ovine submaxillary mucin could not serve as the glycosyl acceptor. The structure of the 14C-labelled oligosaccharide obtained by alkaline-borohydride treatment of the product was identified as Gal beta 1→3(Glc-NAc beta 1→6)N-acetylgalactosaminitol by beta-hexosaminidase treatment, gas chromatography-mass spectrometry and 1H-n.m.r. (270 MHz) analysis. The enzyme is important in the regulation of mucin oligosaccharide biosynthesis.


1986 ◽  
Vol 240 (1) ◽  
pp. 49-56 ◽  
Author(s):  
L Grinblat ◽  
L F Pacheco Bolaños ◽  
A O Stoppani

Heart mitochondria from chronically diabetic rats (‘diabetic mitochondria’), in metabolic State 3, oxidized 3-hydroxybutyrate and acetoacetate at a relatively slow rate, as compared with mitochondria from normal rats (‘normal mitochondria’). No significant differences were observed, however, with pyruvate or L-glutamate plus L-malate as substrates. Diabetic mitochondria also showed decreased 3-hydroxybutyrate dehydrogenase and succinyl-CoA: 3-oxoacid CoA-transferase activities, but cytochrome content and NADH-dehydrogenase, succinate dehydrogenase, cytochrome oxidase and acetoacetyl-CoA thiolase activities proved normal. The decrease of 3-hydroxybutyrate dehydrogenase activity was observed in diabetic mitochondria subjected to different disruption procedures, namely freeze-thawing, sonication or hypoosmotic treatment, between pH 7.5 and 8.5, at temperatures in the range 6-36 degrees C, and in the presence of L-cysteine. Determination of the kinetic parameters of the enzyme reaction in diabetic mitochondria revealed diminution of maximal velocity (Vmax) as its outstanding feature. The decrease in 3-hydroxybutyrate dehydrogenase in diabetic mitochondria was a slow-developing effect, which reached full expression 2-3 months after the onset of diabetes; 1 week after onset, no significant difference between enzyme activity in diabetic and normal mitochondria could be established. Insulin administration to chronically diabetic rats for 2 weeks resulted in limited recovery of enzyme activity. G.l.c. analysis of fatty acid composition and measurement of diphenylhexatriene fluorescence anisotropy failed to reveal significant differences between diabetic and normal mitochondria. The Arrhenius-plot characteristics for 3-hydroxybutyrate dehydrogenase in membranes of diabetic and normal mitochondria were similar. It is assumed that the variation of the assayed enzymes in diabetic mitochondria results from a slow adaptation to the metabolic conditions resulting from diabetes, rather than to insulin deficiency itself.


2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S193-S193
Author(s):  
Emre Karakaya ◽  
Aydincan Akdur ◽  
H Ebru ◽  
Ayvazoglu Soy ◽  
Alev Ok Atilgan ◽  
...  

Abstract Introduction Burn is one of the most severe traumas that causes coagulative destruction of the skin. The use of various products that accelerate wound healing in patients with burn may affect the patient’s survival and reduce the complications that may be seen. In the present study we aimed effects of subcutaneous ozone injection on second degree burn wound. Methods A total of 72 Sprague-Dawley male rats included in the study were divided randomly into three groups (control group (CG), silver sulfadiazine group (SG), ozone group (OG)) and each group was divided randomly two subgroups (as sacrificed on d7 and on d14).A deep second degree scald burns were created on the lower back. In CG subcutaneous 0.9% serum saline was injected daily into the burn area. In SG, burns were dressed with silver sulfadiazine daily and in OG subcutaneous ozone was injected daily into the burn area. Tissue hydroxyproline level measurement and histopathological evaluation were done. Results When the groups were compared in terms of weight change, no significant difference was found on the 7th and 14th days. In the evaluation made in terms of tissue hydroxyproline, tissue hydroxyproline level in OG was found to be significantly higher on both the 7th and 14th days (p &lt; 0.001). In histopathological evaluations, it was determined that wound healing in OG was significantly higher than in the other groups. Conclusions According to the results, subcutaneous ozone therapy is more effective than silver sulphadiazine in the healing process of second-degree burn wounds and it can be safely used in the treatment of burn wounds.


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