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Peña-Corona SI, Vargas-Estrada D, Chávez-Corona JI, Mendoza-Rodríguez CA, Caballero-Chacón S, Pedraza-Chaverri J, Gracia-Mora MI, Galván-Vela DP, García-Rodríguez H, Sánchez-Bartez F, Vergara-Onofre M, Leyva-Gómez G. Vitamin E (α-Tocopherol) Does Not Ameliorate the Toxic Effect of Bisphenol S on the Metabolic Analytes and Pancreas Histoarchitecture of Diabetic Rats. TOXICS 2023; 11:626. [PMID: 37505591 PMCID: PMC10383361 DOI: 10.3390/toxics11070626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/07/2023] [Accepted: 07/14/2023] [Indexed: 07/29/2023]
Abstract
This study investigated whether the coadministration of vitamin E (VitE) diminishes the harmful effects provoked by plasticizer bisphenol S (BPS) in the serum metabolites related to hepatic and renal metabolism, as well as the endocrine pancreatic function in diabetic male Wistar rats. Rats were divided into five groups (n = 5-6); the first group was healthy rats (Ctrl group). The other four groups were diabetic rats induced with 45 mg/kg bw of streptozotocin: Ctrl-D (diabetic control); VitE-D (100 mg/kg bw/d of VitE); BPS-D (100 mg/kg bw/d of BPS); The animals from the VitE + BPS-D group were administered 100 mg/kg bw/d of VitE + 100 mg/kg bw/d of BPS. All compounds were administered orally for 30 days. Body weight, biochemical assays, urinalysis, glucose tolerance test, pancreas histopathology, proximate chemical analysis in feces, and the activity of antioxidants in rat serum were assessed. The coadministration of VitE + BPS produced weight losses, increases in 14 serum analytes, and degeneration in the pancreas. Therefore, the VitE + BPS coadministration did not have a protective effect versus the harmful impact of BPS or the diabetic metabolic state; on the contrary, it partially aggravated the damage produced by the BPS. VitE is likely to have an additive effect on the toxicity of BPS.
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Affiliation(s)
- Sheila I Peña-Corona
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Dinorah Vargas-Estrada
- Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Juan I Chávez-Corona
- Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - C Adriana Mendoza-Rodríguez
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Sara Caballero-Chacón
- Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - José Pedraza-Chaverri
- Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - María Isabel Gracia-Mora
- Departamento de Química Inorgánica y Nuclear, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Diana Patricia Galván-Vela
- Unidad de Investigación Preclínica (UNIPREC), Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Helena García-Rodríguez
- Unidad de Investigación Preclínica (UNIPREC), Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Francisco Sánchez-Bartez
- Departamento de Química Inorgánica y Nuclear, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Marcela Vergara-Onofre
- Departamento de Producción Agricola y Animal, Universidad Autónoma Metropolitana Unidad Xochimilco, Ciudad de México 04960, Mexico
| | - Gerardo Leyva-Gómez
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
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2
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Gawronska-Szklarz B, Musial HD, Loniewski I, Paprota B, Drozdzik M. Lidocaine metabolism in isolated perfused liver from streptozotocin-induced diabetic rats. J Pharm Pharmacol 2010; 58:1073-7. [PMID: 16872554 DOI: 10.1211/jpp.58.8.0008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Insulin deficiency can trigger not only an altered glucose metabolic state but may also affect drug metabolism. The formation rate of the major lidocaine metabolite monoethylglycinxylidide (MEGX) has been shown to reflect the activity of CYP3A2 and CYP1A2. In the present study the effects of streptozotocin-induced diabetes on lidocaine elimination and MEGX formation in a model of isolated, non-recirculated, perfused rat liver with constant flow was evaluated. The parameters describing hepatic lidocaine elimination studied 10 days after streptozotocin administration, i.e. hepatic extraction coefficient (EH), hepatic clearance (ClH) and elimination rate (VL), were significantly decreased in diabetic livers in comparison with the controls. The EH in the controls varied between 0.88±0.07 and 0.93±0.06, whereas in diabetic livers it was markedly reduced to between 0.27±0.15 and 0.39±0.23. The ClH dropped to 8.04±4.12-11.66±2.99mLmin 1 in diabetic rats in comparison to 26.29±2.07–27.94±0.92 mL min−1 in the control animals. The VL was estimated to be 128.08±18.60–136.44±17.59 μg mL−1 in the controls and from 40.87±28.31 μg mL−1 to 56.83±22.16 μg mL−1 in diabetic perfused livers. The major lidocaine metabolite, i.e. MEGX, concentrations were significantly decreased in diabetic rats compared to the controls. The observed changes indicate an impairment of N-deethylation metabolic pathway in streptozotocin-induced diabetic rats, i.e. a possible decrease in the enzymatic activity of CYP3A2 and CYP1A2.
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Affiliation(s)
- Barbara Gawronska-Szklarz
- Department of Pharmacokinetics and Therapeutic Drug Monitoring, Pomeranian Medical University, Powstańców Wlkp. 72, PL 70-111 Szczecin, Poland
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3
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Al-Achi A, Greenwood R. A brief report on some physiological parameters of streptozocin-diabetic rat. Drug Dev Ind Pharm 2001; 27:465-8. [PMID: 11448054 DOI: 10.1081/ddc-100104322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Several biological changes occur when streptozocin is given to experimental animals. The rat streptozocin (STZ) model is extensively used in diabetic experiments. In this brief report, the main physiological characteristics of rats injected with streptozocin are presented. These characteristics are manifested by weight loss, organ weight reduction, serum glucose elevation, decrease in serum insulin level, and other enzyme and hormonal changes. A collection of these parameters may be helpful in establishing a database to describe this model.
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Affiliation(s)
- A Al-Achi
- Campbell University School of Pharmacy, Buies Creek, NC 27506, USA
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4
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Serron SC, Zhang S, Bergeron RM, Backes WL. Effect of hypophysectomy and growth hormone replacement on the modulation of p450 expression after treatment with the aromatic hydrocarbon ethylbenzene. Toxicol Appl Pharmacol 2001; 172:163-71. [PMID: 11312643 DOI: 10.1006/taap.2001.9145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pituitary status has a significant effect on the expression of several cytochrome P450 enzymes. The goal of this study was to examine the role of pituitary input on the modulation of CYP2C11 and CYP2B after treatment with the aromatic hydrocarbon ethylbenzene (EB). Intact, hypophysectomized (HX), and HX rats supplemented with pulsatile growth hormone (GH) were treated with corn oil or EB and the effects on hepatic P450 expression were determined. Hypophysectomy caused a 50% decrease in CYP2C11 protein in untreated rats, whereas GH supplementation returned protein to control levels. EB administration also decreased CYP2C11 protein in intact rats; however, this decrease was not observed after EB treatment in HX or HX + GH groups. CYP2C11-dependent testosterone 2alpha-hydroxylation followed a similar pattern as CYP2C11 protein, except that the activity was only partially restored by GH replacement. CYP2B levels were also substantially influenced by hypophysectomy. Intact rats exhibited a 100-fold increase in CYP2B1 mRNA, reaching a maximum 12 h after EB administration. A much smaller response (ca. 20-fold) was observed in HX rats, reaching a maximum 24 h after EB treatment. This effect was not reversed by GH supplementation. The half-life for EB was significantly increased from 8 h in intact rats to 14 h in HX rats, suggesting higher plasma EB concentrations after EB administration to HX rats. These results indicate that CYP2C11 and CYP2B become less responsive to EB-dependent modulation in HX rats, a response that cannot be explained simply by absence of GH or by altered EB pharmacokinetics in HX animals.
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Affiliation(s)
- S C Serron
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana, 70112, USA
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5
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Lucas D, Farez C, Bardou LG, Vaisse J, Attali JR, Valensi P. Cytochrome P450 2E1 activity in diabetic and obese patients as assessed by chlorzoxazone hydroxylation. Fundam Clin Pharmacol 1998; 12:553-8. [PMID: 9794154 DOI: 10.1111/j.1472-8206.1998.tb00985.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cytochrome P450 2E1 (CYP2E1) is a phase I detoxification enzyme, which is induced by chronic alcohol consumption. It is involved in the activation of numerous carcinogens and in the production of free radicals. As it has previously been shown to be induced in diabetic and obese rats, the aim of this study was to investigate its induction level in poorly-controlled diabetics and in obese patients (Body Mass Index > 30 kg/m2). CYP2E1 activity was determined in 35 diabetic and 17 obese patients by using the in vivo chlorzoxazone hydroxylation test. Even though the glucidic parameters were highly disturbed (mean fasting glycemia > 7.9 mmol/L, post prandial glycemia > 12.2 mmol/L and fructosamine > 326 mumol/L), CYP2E1 activity was not enhanced either in insulin-dependent diabetics (IDDs, n = 7) nor in non-obese non-insulin-dependent diabetics (NIDDs, n = 15) when compared to controls (n = 42) (0.21 +/- 0.03, 0.33 +/- 0.03 and 0.30 +/- 0.02, respectively, mean +/- SEM). However, this activity was lower in IDDs when compared to NIDDs (P < 0.05). In obese patients, with (n = 13) or without (n = 17) NIDD mellitus, CYP2E1 activity was increased by a mean of 40% when compared to controls. In addition, positive correlations were found in all subjects (controls or patients, n = 74) between CYP2E1 activity and serum cholesterol (r = 0.42, P < 0.0001), triglycerides (r = 0.44, P < 0.0001) and BMI (r = 0.36, P < 0.001). Accordingly, subjects with cholesterol and/or triglyceride serum levels above 6.4 and 1.8 mmol/L, respectively, displayed a mean increase of 40% of their CYP2E1 activity vs subjects within the above values. It is believed that individuals with increased CYP2E1 activity are more susceptible to the adverse effects of CYP2E1-mediated activation of toxins and carcinogens.
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Affiliation(s)
- D Lucas
- Laboratoires de Biochimie-Nutrition, Faculté de Médecine de Brest, France
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6
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Clarke J, Snelling J, Ioannides C, Flatt PR, Barnett CR. Effect of vitamin C supplementation on hepatic cytochrome P450 mixed-function oxidase activity in streptozotocin-diabetic rats. Toxicol Lett 1996; 89:249-56. [PMID: 9001594 DOI: 10.1016/s0378-4274(96)03822-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effect of vitamin C supplementation on hepatic cytochrome P450 expression was investigated in streptozotocin (STZ) diabetic male Wistar Albino rats. STZ-treated rats displayed the usual characteristics of diabetes including; hyperphagia, polydipsia, decreased body weight gain and also the increased expression and activity of hepatic CYP1A, 2B, 2E and 4A proteins. Vitamin C administration in drinking water (2% w/v) was associated with significant decreases in the levels of hyperglycaemia (P < 0.05), glycosylated haemoglobin (P < 0.05), hyperlipidaemia (P < 0.001), and hyperketonaemia (P < 0.001) associated with STZ-diabetes. Vitamin C-treatment selectively reduced the activity and expression of CYP2E proteins (P < 0.001). These effects on CYP2E expression may be mediated by the reduced levels of circulating ketone bodies, however, a direct effect on CYP2E expression in diabetes cannot be discounted.
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Affiliation(s)
- J Clarke
- School of Biomedical Sciences, University of Ulster, Londonderry, Northern Ireland, UK
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7
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Raucy JL, Curley G, Carpenter SP. Use of lymphocytes for assessing ethanol-mediated alterations in the expression of hepatic cytochrome P4502E1. Alcohol Clin Exp Res 1995; 19:1369-75. [PMID: 8749797 DOI: 10.1111/j.1530-0277.1995.tb00994.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The ethanol-inducible cytochrome P4502E1 (2E1) is involved in the bioactivation of numerous hepatotoxins and hepatocarcinogens. Because high levels of expression may enhance the degree and severity of hepatotoxicity from exposure to chemicals metabolized by this enzyme, a relatively noninvasive method to phenotypically distinguish those individuals exhibiting elevated concentrations of 2E1 may be useful. With this in mind, we examined whether ethanol exposure could alter 2E1 in rabbit white blood cells and liver in a similar manner. Microsomes prepared from freshly isolated, rather than cultured cells, were used to immunochemically detect 2E1. The enzyme was found in lymphocytes and neutrophils. Lymphocytes, which comprise the majority of the white cell population in rabbits, were monitored for changes in 2E1 protein levels after ethanol exposure and compared with alterations of the hepatic enzyme. Results presented herein demonstrate that the degree of enhancement in 2E1 expression of lymphocytes and liver was dependent on the length and dose of alcohol exposure. Indeed, correlations were observed between blood alcohol concentrations and 2E1 content in lymphocytes (r = 0.65, p < 0.01) and liver (r = 0.60, p < 0.01). The greatest increase in 2E1 (6- to 10-fold) occurred in both liver and lymphocytes at a dose of 15% ethanol for 12 days of treatment. This induction was evident regardless of whether blood was taken from treated and compared with untreated rabbits or if white cells were obtained from the same animal before and after ethanol exposure. The latter findings demonstrate that changes in lymphocyte 2E1 were caused by ethanol exposure and not to variability in enzyme expression among rabbits. Interestingly, at the 10% dose, elevation of 2E1 was noted as early as 3 days, declined at 6 days, and at 12 and 24 days returned to slightly higher levels than those seen at the 3-day exposure period. This pattern of 2E1 elevation was observed in both the liver and lymphocytes. In fact, at all exposure periods and at the two doses of alcohol examined, a correlation (r = 0.70, p < 0.01) was observed between lymphocyte and liver 2E1 content. Collectively, these studies show that induction of 2E1 in lymphocytes and liver occurs in a parallel fashion. Furthermore, results suggest that blood 2E1 may be used in humans as a phenotypic marker for xenobiotic-promoted alterations in the expression of the liver enzyme. These findings should have a significant impact on in vivo monitoring of this P450 enzyme.
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Affiliation(s)
- J L Raucy
- University of New Mexico, College of Pharmacy, Albuquerque, USA
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8
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Shimojo N. Cytochrome P450 changes in rats with streptozocin-induced diabetes. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1994; 26:1261-8. [PMID: 7880321 DOI: 10.1016/0020-711x(94)90095-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
It is known that the metabolism of some drugs is altered in diabetic patients and in rats with experimental diabetes induced by chemical agents, such as streptozocin. The induction and/or suppression of hepatic cytochrome P450 isozymes seen in diabetes seem to contribute to this alteration. Both metabolic and hormonal disturbances following insulin deficiency in diabetic rats are responsible for these changes. Marked changes in hepatic P450 isozymes in diabetic rats include increases in the isozymes induced by ketones and lipids, including fatty acids, and decreases in the isozymes regulated by growth hormone and testosterone. Suppressed secretion of thyroid hormones also participates in the mechanism causing these changes. Analysis of cytochrome P450 isozymes in diabetic rats is helpful in elucidating the impaired metabolism of some endogenous substrates catalyzed by the cytochrome P450, such as steroid hormones and fatty acids, in diabetes. The results of these analyses also provide insight into the prescription of drugs for diabetic patients.
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Affiliation(s)
- N Shimojo
- Department of Laboratory Medicine, Osaka City University Medical School, Japan
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9
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Kraner JC, Lasker JM, Corcoran GB, Ray SD, Raucy JL. Induction of P4502E1 by acetone in isolated rabbit hepatocytes. Role of increased protein and mRNA synthesis. Biochem Pharmacol 1993; 45:1483-92. [PMID: 8471070 DOI: 10.1016/0006-2952(93)90049-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The molecular mechanism(s) underlying induction of the hepatic microsomal cytochrome P4502E1 (2E1) by xenobiotics (e.g. ethanol and acetone) is controversial. Proposed mechanisms include increased rates of enzyme synthesis due to elevated 2E1 mRNA levels, enhanced translation of pre-existing mRNA, or stabilization of 2E1 protein. To further assess which, if any, of these events predominates during the initial stages of 2E1 protein induction, we investigated the effects of acetone treatment on 2E1 content in cultured rabbit hepatocytes, an in vitro system that allows for precise control of the cellular mileau. Hepatocytes harvested from female rabbits and plated on plastic dishes with serum-supplemented medium were 90-100% viable for at least 48 hr in culture. Analysis of immunoreactive 2E1 content and aniline hydroxylase activity in microsomes isolated from hepatocytes cultured for up to 24 hr revealed that 2E1 expression was equal to that of microsomes from unplated cells and by 48 hr of culture, 2E1 levels decreased by only 35%. Moreover, microsomes isolated from cells exposed to 17 mM acetone for 24 hr exhibited a 53 and 62% increase in aniline hydroxylase activity and 2E1 content, respectively, compared to untreated cells. To explain these increases, the rate of 2E1 protein synthesis was determined in untreated cells or in cells treated with 17 mM acetone by first exposing hepatocytes to medium supplemented with 35S-labeled methionine and cysteine ([35S]Met/Cys) and subsequently assessing radiolabel incorporation into 2E1 protein. While no difference was found between untreated and acetone-treated cells in the incorporation of [35S]Met/Cys into trichloracetic acid-precipitable microsomal proteins, immunoaffinity purification of 2E1 revealed that incorporation of 35S-labeled amino acids specifically into 2E1 was elevated by acetone to 200% of control values. Treatment of hepatocytes with the transcriptional inhibitor, alpha-amanitin, markedly inhibited this acetone-mediated increase in [35S]Met/Cys incorporation into 2E1. Analysis of hepatocyte RNA revealed that acetone increased 2E1 mRNA to 130 and 160% of control levels at 6 and 24 hr, respectively, and that these increases were prevented by pretreatment with alpha-amanitin. Our results indicate that acetone increases 2E1 protein levels in cultured rabbit hepatocytes by stimulating its rate of de novo synthesis. Since this increase in 2E1 synthesis stems, at least in part, from the acetone-mediated enhancement of hepatocyte 2E1 mRNA content and is inhibitable by alpha-amanitin, transcriptional activation of the rabbit CYP2E1 gene is apparently involved in the induction of 2E1 protein by acetone.
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Affiliation(s)
- J C Kraner
- Toxicology Program, College of Pharmacy, University of New Mexico, Albuquerque 87131
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10
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Vega P, Gaule C, Mancilla J, Del Villar E. Comparison of alloxan and streptozotocin induced diabetes in rats: differential effects on microsomal drug metabolism. GENERAL PHARMACOLOGY 1993; 24:489-95. [PMID: 8482528 DOI: 10.1016/0306-3623(93)90336-v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1. Liver microsomes from alloxan or streptozotocin diabetic rats displayed differential drug metabolizing abilities in vitro. 2. Only streptozotocin liver microsomes exhibited changes in the cytochrome P-450 normal spectral characteristics. 3. Overall testosterone metabolism was significantly increased in streptozotocin diabetic liver microsomes, whereas it was markedly decreased in alloxan diabetes. Mixed function oxidase activity for aminopyrine was similar. 4. Glucuronidation reaction rates towards morphine, oestrone and p-nitrophenol were also markedly distinct in both models as well as after insulin treatment. 5. Results suggest that diabetogenic agents modify sex related isoenzymes of cytochrome P-450 differently and selectively reduce the synthesis of certain UDP-glucuronyltransferase forms.
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Affiliation(s)
- P Vega
- Department of Biochemistry, Faculty of Medicine, University of Chile, Santiago
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11
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Abstract
Numerous halogenated hydrocarbons of the alkane, alkene, and alkyne classes are metabolized by P450 enzymes to products that elicit cytotoxic and/or carcinogenic effects. Such halogenated hydrocarbons include anesthetics (e.g., halothane and enflurane) and industrial solvents (e.g., carbon tetrachloride, chloroform, and vinylidine chloride). Formation of reaction intermediates from these compounds occurs via P450-promoted dehalogenation, reduction, or reductive oxygenation, with certain hydrocarbons undergoing all three reaction types. Of the multiple forms of P450 present in liver microsomes, P4502E1 has been identified as the primary catalyst of hydrocarbon bioactivation in animals and, most likely, in humans as well. As hepatic concentrations of this P450 enzyme are highly inducible by ethanol and similar agents, prior exposure to 2E1-inducing compounds can play a pivotal role in halogenated hydrocarbon toxicity. Considering that metabolism governs the cytotoxicity and carcinogenicity of halogenated hydrocarbons, an understanding of the mechanism(s) underlying 2E1 induction in man becomes all the more important.
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Affiliation(s)
- J L Raucy
- Toxicology Program, College of Pharmacy, University of New Mexico, Albuquerque 87131
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12
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Mimouni V, Poisson JP. Altered desaturase activities and fatty acid composition in liver microsomes of spontaneously diabetic Wistar BB rat. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1123:296-302. [PMID: 1536868 DOI: 10.1016/0005-2760(92)90010-s] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We examined the activities of delta 9, delta 6 and delta 5 desaturases and fatty acid composition of liver microsomes in the insulin-dependent spontaneously diabetic adult female Wistar Bio-Breeding (BB) rat. The diabetic BB rats were subcutaneously injected with different doses of protamine zinc insulin in order to be killed in hyper-, normo- or hypo-glycemic states. Desaturase activities, which are partially inhibited by spontaneous diabetes during the normo- and hyper-glycemic periods, were similarly affected by the various insulin treatment; delta 9 desaturase activity being more depressed than the desaturase activities of either delta 6 of delta 5. Insulin treatment with 10 I.U./kg body weight twice a day for 2 days was able to restore the delta 9, delta 6 and delta 5 desaturase activities to control levels during the hypoglycemic period. The microsomal fatty acid composition of BB rats liver was not consistent with the desaturase activities, particularly delta 9 desaturase activity, during the different states of glycemia, indicating that they are not closely linked in a direct cause-effect relationship.
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Affiliation(s)
- V Mimouni
- Unité de Recherche de Nutrition Cellulaire et Métabolique, Université de Bourgogne, Faculté des Sciences Mirande, Dijon, France
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13
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Tuñon MJ, Gonzalez P, Garcia-Pardo LA, Gonzalez J. Hepatic transport of bilirubin in rats with streptozotocin-induced diabetes. J Hepatol 1991; 13:71-7. [PMID: 1833441 DOI: 10.1016/0168-8278(91)90866-a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This study was undertaken to evaluate the effects of streptozotocin-induced diabetes on the hepatic transport of bilirubin in male Wistar rats. Rats were pretreated with streptozotocin (60 mg/kg i.p.) to induce uncontrolled diabetes. Six days later endogenous biliary excretion and plasma bilirubin concentration were significantly enhanced compared to control animals (+36% and +46%, respectively), while the blood levels of free hemoglobin remained unchanged. Following a bilirubin load, the maximal biliary excretion of the pigment (Tm) in diabetic animals was significantly enhanced compared to control animals (+49%). Liver and plasma bilirubin concentrations at the end of bilirubin administration were significantly reduced (-28% and -30%, respectively). Bilirubin UDP-glucuronosyltransferase activity and UDP-glucose concentration in liver were significantly enhanced (+31% and +81%, respectively), as was the biliary excretion of unconjugated bilirubin (+37%) and bilirubin mono- (+38%) and diconjugates (+53%). When streptozotocin-diabetic rats were treated with insulin, the parameters of bilirubin transport and metabolism were significantly reduced compared to diabetic animals receiving no hormone replacement. In summary, our data indicate that in short-term streptozotocin-diabetic rats there is increased bilirubin production as well as enhanced hepatic conjugation and subsequent biliary excretion of the pigment. These effects appear to be a direct consequence of diabetes.
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Affiliation(s)
- M J Tuñon
- Department of Physiology, Pharmacology and Toxicology, University of Leon, Spain
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14
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Lindsay RM, Baird JD. The effect of diabetes on the in vivo acetylation capacity of the spontaneously diabetic, insulin-dependent BB/Edinburgh Wistar rat. Biochem Pharmacol 1991; 41:425-30. [PMID: 1994900 DOI: 10.1016/0006-2952(91)90540-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In contrast to previous studies using chemically-induced diabetic rats, the in vivo acetylation of sulphamethazine is increased in spontaneously diabetic, insulin-dependent BB/Edinburgh (BB/E) Wistar rats compared to non-diabetic control animals from the same colony. In both diabetic and non-diabetic rats, male animals had a significantly higher acetylation capacity than female animals. The percentage recovery of the administered dose was significantly higher in urine samples from female rats.
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Affiliation(s)
- R M Lindsay
- University of Edinburgh, Department of Medicine, Western General Hospital, U.K
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15
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Cameron DF, Rountree J, Schultz RE, Repetta D, Murray FT. Sustained hyperglycemia results in testicular dysfunction and reduced fertility potential in BBWOR diabetic rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1990; 259:E881-9. [PMID: 2260654 DOI: 10.1152/ajpendo.1990.259.6.e881] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Rats with short-term diabetes show a greater than 50% reduction of serum testosterone and increased lipid in Leydig cells but normal testicular structure. The purpose of this study was to determine the extent of testicular pathology (morphology index), integrity of the blood-testis barrier, daily sperm production (DSP), number of Leydig cells per testis (LC/T), and total trunk testosterone (TTT) in diabetic rats (BBWORdp) with long-term hyperglycemia (300-350 mg/dl for greater than 180 days) and to evaluate its effects on fertility potential. Results were compared with similarly aged normoglycemic rats (BBWORdr) and normal control Wistar rats. After 6 mo of diabetes, testis weights, DSPs, TTTs, and the morphology index were significantly reduced. The LC/T was not different from BBWORdr rats. The blood-testis barrier appeared intact, although structural abnormalities were noted in Sertoli-Sertoli junction complexes. There was a significant reduction in the number of pregnancies per rat and implantations per pregnancy in matings utilizing the diabetic BBWORdp rat and control Wistar female rats. Results indicate that long-term diabetes with sustained hyperglycemia leads to significant testicular dysfunction associated with decreased fertility potential.
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Affiliation(s)
- D F Cameron
- Department of Anatomy, University of South Florida, Tampa 33612
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16
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Del Villar E, Vega P, Gaule C, Sanchez E. Diabetes in female rats; changes in liver microsomal aminopyrine N-demethylase and UDP-glucuronyl transferase activities. Eur J Drug Metab Pharmacokinet 1990; 15:279-85. [PMID: 2128478 DOI: 10.1007/bf03190216] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Short or long term diabetes in female rats produced remarkable activation of aminopyrine N-demethylation, inhibition of oestrone and p-nitrophenol glucuronidation and no changes in morphine UDP-glucuronyltransferase activity in vitro. Km and Vmax for these reactions were determined. Insulin treatment partially antagonized diabetes activation of aminopyrine N-demethylation: it restored decreased UDP-glucuronyltransferase activities for oestrone and p-nitrophenol only in long term and short term diabetes, respectively. Insulin also markedly inhibited morphine glucuronidation. Triton X-100 also displayed a differential pattern of activation for the glucuronidation reactions in liver microsomes of diabetic rats. Results suggest that diabetes in female rats may increase the actual amount of enzyme protein for aminopyrine metabolism and to decrease that for oestrone and p-nitrophenol.
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Affiliation(s)
- E Del Villar
- Department of Biochemistry Faculty of Medicine, University of Chile, Santiago
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17
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Barnett CR, Flatt PR, Ioannides C. Induction of hepatic microsomal P450 I and IIB proteins by hyperketonaemia. Biochem Pharmacol 1990; 40:393-7. [PMID: 2375773 DOI: 10.1016/0006-2952(90)90708-s] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- C R Barnett
- Department of Biochemistry, University of Surrey, Guildford, U.K
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18
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Zaluzny L, Farrell GC, Murray M. Effect of genetic obesity and experimental diabetes on hepatic microsomal mixed function oxidase activities. J Gastroenterol Hepatol 1990; 5:256-63. [PMID: 2103407 DOI: 10.1111/j.1440-1746.1990.tb01626.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In male rats, genetic obesity and experimental diabetes are associated with altered activities of several of the hepatic microsomal P-450 isozymes concerned with steroid and xenobiotic oxidation. The present study examined the roles of insulin and ketonaemia in effecting these changes. In obese male Zucker rats, androstenedione 6 beta-, 16 alpha- and 16 beta-hydroxylase activities (mediated by P450PCN-E, P-450UT-A and P450PB-B, respectively) were significantly decreased to 21%, 20% and 43% of lean control. Obesity was also associated with a significant decrease in the activities of N-nitrosodimethylamine demethylase (P-450j) and aniline p-hydroxylase to about 70%. A similar decrease in total microsomal P-450 was also observed. Androstenedione 7 alpha-hydroxylase activity (mediated by P-450UT-F) was unchanged in these animals. In streptozotocin-induced diabetic male Wistar rats, androstenedione 7 alpha- and 16 beta-hydroxylase activities were significantly elevated to 230% and 270% of control, respectively. Significant increases in the rates of N-nitrosodimethylamine demethylase and aniline p-hydroxylase were also noted in diabetic rat liver. In contrast, the activity of P-450UT-A was reduced to 30% of control and P-450PCN-E-specific 6 beta-hydroxylation was unchanged. Control of the diabetic state with insulin treatment reversed all the changes in P-450-mediated activities. Significant correlations were found between serum concentrations of insulin and catalytic activities of P-450PB-B (rho = -0.46), P-450UT-F (rho = -0.65) and P-450j (rho = -0.71). Positive correlations of the same magnitude were also found between these mixed function oxidase activities and beta-hydroxybutyrate.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L Zaluzny
- Department of Medicine, University of Sydney, Westmead Hospital, New South Wales, Australia
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19
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Lindsay RM, Baty JD. The effect of streptozotocin-induced diabetes on the in vivo acetylation capacity and the in vitro blood N-acetyltransferase activity of the adult male Sprague-Dawley rat. Biochem Pharmacol 1990; 39:1193-7. [PMID: 2322304 DOI: 10.1016/0006-2952(90)90262-j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Induction of experimental diabetes using streptozotocin significantly reduced the extent of sulphamethazine acetylation by Sprague-Dawley rats. This treatment did not significantly change the total amount of sulphonomide excreted in the urine. The in vitro blood N-acetyltransferase activity of rats treated with streptozotocin was significantly higher than that of untreated animals. Increasing the in vitro glucose concentration of blood samples from both groups significantly increased the amount of acetylsulphamethazine produced.
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Affiliation(s)
- R M Lindsay
- Department of Biochemical Medicine (University of Dundee), Ninewells Hospital and Medical School, U.K
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20
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Marin JJ, Herreros M, Villanueva GR, Perez-Barriocanal F, el-Mir MY, Medina JM. Effect of streptozotocin-induced diabetes on sex differences in biliary lipid secretion in the rat. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1043:106-12. [PMID: 2310755 DOI: 10.1016/0005-2760(90)90116-f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Diabetes mellitus is often associated with lipid abnormalities that may differ with sex. In this work we studied biliary lipid secretion in male and female anaesthetized Wistar rats (250 g). Diabetes was induced by a single intraperitoneal injection of streptozotocin (6 mg/100 body weight) 6 days before carrying out the studies on bile secretion. Our results confirm the existence of sex differences in bile formation and composition, most of them probably due to a higher (+27%) bile acid output in the female animals. Diabetes induced profound alterations in these sex differences. (a) Bile flow was reduced in both sexes, but more markedly so in female diabetic rats; thus the difference observed in healthy animals was reduced (from 2.22 to 1.58 and from 1.84 to 1.40 microliters/min per g liver in female and male rats, respectively). (b) Bile acid and phosphatidylcholine outputs were increased to a similar extent (bile acid output: from 46.7 to 55.8 nmol/min per g liver, in females and from 36.8 to 50.7 nmol/min per g liver, in males; phosphatidylcholine output: from 3.3 to 13.1 nmol/min per g liver, in females and from 4.5 to 12.5 nmol/min per g liver, in males), and hence the sex differences were abolished. (c) Cholesterol output was increased in both sexes, but this enhancement was significantly higher in female rats (from 0.75 to 1.31 and from 0.65 to 0.89 nmol/min per g liver, in females and males, respectively). (d) The fractional pool of phospholipid species secreted into bile was different in female compared with male rats. The percentage of phosphatidylcholine was higher in female than in male healthy rats. Streptozotocin treatment reversed this proportion, which suggests that changes in the phospholipid composition of the canalicular plasma membrane may play a role in the observed alterations in biliary lipid secretion during diabetes mellitus. Most of the above-described streptozotocin-induced changes were prevented by insulin replacement from the 3rd to the 6th days after streptozotocin injection. In summary, the present study describes alterations in sex differences in biliary lipid secretion of streptozotocin-induced diabetes. These changes are dependent on the insulin deficiency state rather than on a direct hepatotoxicity of the diabetogenic drug.
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Affiliation(s)
- J J Marin
- Department of Physiology and Pharmacology, University of Salamanca, Spain
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21
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22
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Yamazoe Y, Murayama N, Shimada M, Yamauchi K, Kato R. Cytochrome P450 in livers of diabetic rats: regulation by growth hormone and insulin. Arch Biochem Biophys 1989; 268:567-75. [PMID: 2521554 DOI: 10.1016/0003-9861(89)90324-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effects of pituitary and pancreatic hormones on the change in hepatic cytochrome P450s were studied in alloxan- or streptozotocin-induced male rats. In two major sex-specific forms, P450-male and P450(6 beta-1), the former was decreased in chronic (5 week) diabetes to only less than one-third of controls and the latter was also reduced in early (1 week) diabetes. In contrast, a main phenobarbital-inducible form, P450b, was enhanced 25- to 30-fold in these diabetic rats. 3-Methylcholanthrene-inducible P448H was also elevated 3-fold in alloxan-induced diabetes. These changes in hepatic contents of P450-male, P450-6 beta-1, and P450b, which are under the regulation of pituitary growth hormone, associated well with the reported results of time-dependent changes in growth hormone levels in diabetes (G.S. Tannenbaum (1981) Endocrinology 108, 76-82), suggesting that the change in growth hormone level is a factor responsible for alterations in hepatic cytochrome P450s. Normalizing effects of insulin on these forms were also studied. Treatment of diabetic rats with insulin reversed the decreased amounts of both P450-male protein and mRNA. Insulin also normalized hepatic contents of P450b, P4506 beta-1, and P448H. However, the treatment of hypophysectomized rats with insulin had no effect, and treatment of diabetic rats with growth hormone or a suppressing agent of somatostatin, cysteamine, showed trivial effects on P450-male and P450b. These results suggest that insulin does not act directly as a substitute of growth hormone, but exerts its effect indirectly through the normalization of a growth hormone-mediated process(es) in diabetic rats.
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Affiliation(s)
- Y Yamazoe
- Department of Pharmacology, School of Medicine, Keio University, Tokyo, Japan
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23
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LeBlanc GA, Waxman DJ. Feminization of rat hepatic P-450 expression by cisplatin. Evidence for perturbations in the hormonal regulation of steroid-metabolizing enzymes. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)37649-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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24
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Abstract
The hepatic content of two individual cytochrome P-450 enzymes was analyzed in spontaneously diabetic (BB/Wor) male rats. The major male-specific form, RLM5, was found to be slightly decreased in livers of male rats shortly after the onset of diabetes. In contrast, the level of RLM6 was elevated in livers of diabetic rats that had not received insulin and had become ketotic. These results confirm that the changes in some individual forms of cytochrome P-450 after chemical (streptozotocin) induction of diabetes are also seen in the spontaneously diabetic animal. The earlier observed alterations in cytochrome P-450 are therefore due to the state of diabetes and not to inductive or depressive effects of streptozotocin.
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Affiliation(s)
- L V Favreau
- Department of Pharmacology, University of Connecticut Health Center, Farmington 06032
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25
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Affiliation(s)
- P Skett
- Department of Pharmacology, University, Glasgow, Scotland, U.K
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26
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Smith DR, Rodway MR, Haniak WA, Bellward GD. Hepatic estrogen and androgen receptors and binding proteins in streptozotocin-diabetic male Wistar rats. Diabetologia 1987; 30:957-62. [PMID: 3325327 DOI: 10.1007/bf00295881] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have previously shown that there are decreases in the sex differences seen in certain hepatic drug and steroid metabolising enzymes in rats with early (4 day) streptozotocin-induced diabetes. We postulated that hepatic sex hormone receptors or binding proteins might be involved in modulation of the sex differences noted in metabolism. In the present study, we measured the binding kinetics of the hepatic cytosolic estrogen receptor and androgen receptor, along with the high capacity-low affinity estrogen binding protein. At 4 or 10 days post-streptozotocin (60 mg/kg intravenously), there was no change in the maximum binding capacity of the estrogen receptor, nor in the hormone affinity of any of the three proteins. However, the binding capacity of the androgen receptor and estrogen binding protein in the diabetic animals was decreased to less than half of control levels. This effect could not be reversed by hormone replacement with any of the following regimens: protamine zinc insulin, 10 U/kg subcutaneously once a day; Toronto insulin, 15 U/kg subcutaneously twice a day; testosterone enanthate, 1 mg/kg s.c. once a day; triiodothyronine, 30 micrograms/kg s.c. daily; ovine growth hormone: 0.02 U/h s.c., 30 micrograms s.c. 7 times daily, 30 micrograms i.v. 4 times daily; or various combinations of these hormones. Stress, such as 4 intravenous injections of saline per day, was noted to decrease the binding capacity of the estrogen binding protein. Therefore, we measured the basal serum corticosterone levels, which were not significantly different from control values in untreated or insulin-treated diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D R Smith
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
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27
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Grant MH, Duthie SJ. Conjugation reactions in hepatocytes isolated from streptozotocin-induced diabetic rats. Biochem Pharmacol 1987; 36:3647-55. [PMID: 3675622 DOI: 10.1016/0006-2952(87)90015-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The activities of three drug conjugation reactions, glutathione, glucuronic acid and sulphate conjugation and the synthesis of glutathione, have been measured in hepatocytes isolated from streptozotocin-induced male diabetic rats. The intracellular content of reduced glutathione (GSH) was decreased in diabetic rat hepatocytes compared with controls. Following depletion of the intracellular GSH stores with diethylmaleate, the resynthesis of GSH in the presence of 0.5 mM L-methionine, occurred faster in diabetic rat hepatocytes than in those from control rats indicating that the cystathione pathway may be more efficient in the diabetic animals. In contrast, there was no significant difference in the resynthesis of GSH between control and diabetic rat hepatocytes in the presence of L-cysteine. The GSH conjugation of 1-chloro-2,4-dinitrobenzene (CDNB) and 3,4-dichloronitrobenzene (DCNB) was deficient in diabetic rat hepatocytes, although only the effect on the former reaction was statistically significant (P less than 0.05). The Vmax for CDNB conjugation was significantly lower (P less than 0.05) in cytosolic fractions prepared from diabetic rat liver than in control rat liver fractions. This was accompanied by an increase in the affinity of the enzyme for CDNB. In contrast, the Vmax and Km for the conjugation of DCNB in cytosolic fractions were unaffected by the induced-diabetes. Glucuronic acid conjugation of both 1-naphthol and phenolphthalein was markedly deficient in diabetic rat hepatocytes. The intracellular concentrations of the cofactor for glucuronidation, UDP-glucuronic acid, were decreased in diabetic rat liver and this was thought to contribute to the defect in glucuronidation. The sulphation of 1-naphthol was not significantly altered by the induced diabetes. Deficiencies in glutathione and glucuronic acid conjugation in streptozotocin-induced diabetic rats may result in an increased susceptibility to xenobiotic induced cytotoxicity.
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Affiliation(s)
- M H Grant
- Department of Medicine and Therapeutics, University of Aberdeen, Foresterhill, U.K
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28
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Abstract
Insulin administration has previously been shown to reverse the effects of chemically-induced and spontaneous diabetes on hepatic drug and steroid metabolism in the rat. The complex network of the intact hormonal system of the body and its physiological feedback mechanisms makes it difficult to ascribe the effects seen to any particular hormones. The present study investigated the effect of insulin on hepatic steroid metabolism in the absence of other hormonal influences by using isolated rat liver cells. Insulin (10(-9) M) produced two peaks of increased enzyme activity in the hepatocytes (at 1/2 hr and 24 hr). Dose-response curves at 1/2 hr and 24 hr insulin preincubation suggest that these two peaks are probably generated by different mechanisms. The absence of any significant changes in cytochrome P-450 content after 1/2, 1 and 2 hr of insulin treatment indicates that the increase in steroid metabolizing enzyme activities is not due to an increase in de-novo enzyme synthesis. Our observations provide further evidence for the role played by insulin in the regulation of hepatic steroid and drug metabolism in the rat.
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Affiliation(s)
- A H Hussin
- Department of Pharmacology, University, Glasgow, Scotland, U.K
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29
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Favreau LV, Malchoff DM, Mole JE, Schenkman JB. Responses to insulin by two forms of rat hepatic microsomal cytochrome P-450 that undergo major (RLM6) and minor (RLM5b) elevations in diabetes. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47940-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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30
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Affiliation(s)
- G C Farrell
- Department of Medicine, University of Sydney, Westmead Hospital, Australia
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31
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Rouer E, Beaune P, Leroux JP. Immunoquantitation of some cytochrome P-450 isozymes in liver microsomes from streptozotocin-diabetic rats. EXPERIENTIA 1986; 42:1162-3. [PMID: 3770136 DOI: 10.1007/bf01941293] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Streptozotocin-diabetes in rats leads to a decrease of cytochrome P-450 UT-A (the major form in control rats) and an increase of cytochrome P-450 PB-B (the major one induced by phenobarbital treatment) in liver microsomes. The increased benzphetamine-N-demethylase activity can be related to the induction of cytochrome P-450 PB-B.
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32
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Longhurst PA, LaCagnin LB, Staats DA, Colby HD. Changes in hepatic drug metabolism in alloxan-diabetic male rabbits. Biochem Pharmacol 1986; 35:1768-71. [PMID: 3085677 DOI: 10.1016/0006-2952(86)90341-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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33
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Zysset T, Sommer L. Diabetes alters drug metabolism--in vivo studies in a streptozotozin-diabetic rat model. EXPERIENTIA 1986; 42:560-2. [PMID: 3086116 DOI: 10.1007/bf01946703] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The influence of experimental streptozotozin-induced diabetes on hepatic drug metabolism in vivo has been studied in rats, using 14CO2-exhalation after 14C-aminopyrine injection. Male diabetic rats showed a decreased (-18%), females an increased (+19%) 14CO2-exhalation compared to controls, indicating altered hepatic drug metabolism due to diabetes.
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34
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Morrison MH, Barber HE, Foschi PG, Hawksworth GM. The kinetics of 4-nitrophenol conjugation by perfused livers and hepatic microsomes from streptozocin-induced diabetic rats. J Pharm Pharmacol 1986; 38:188-94. [PMID: 2871153 DOI: 10.1111/j.2042-7158.1986.tb04542.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The formation of both glucuronide and sulphate conjugates of 4-nitrophenol is deficient in perfused livers from male diabetic rats. Experiments with 'native' hepatic microsomes demonstrated that the defect in glucuronidation is due to a decrease in the maximal velocity of the reaction. There is no alteration in the affinity of the glucuronyltransferase for 4-nitrophenol. Non-linear regression analysis of the 4-nitrophenol liver perfusate concentrations showed that the elimination follows saturable Michaelis-Menten kinetics. Clearance values in 'native' microsomal preparations and in perfused livers were calculated and found to be similar in both systems. This provides evidence that glucuronyltransferase is 'native' in the intact liver.
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35
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Ryan DE, Ramanathan L, Iida S, Thomas PE, Haniu M, Shively JE, Lieber CS, Levin W. Characterization of a major form of rat hepatic microsomal cytochrome P-450 induced by isoniazid. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(18)88984-0] [Citation(s) in RCA: 165] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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36
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Skett P, Joels LA. Different effects of acute and chronic diabetes mellitus on hepatic drug metabolism in the rat. Biochem Pharmacol 1985; 34:287-9. [PMID: 3966932 DOI: 10.1016/0006-2952(85)90139-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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37
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Morrison MH, Hawksworth GM. Glucuronic acid conjugation by hepatic microsomal fractions isolated from streptozotocin-induced diabetic rats. Biochem Pharmacol 1984; 33:3833-8. [PMID: 6439213 DOI: 10.1016/0006-2952(84)90048-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The hepatic glucuronidation of 1-naphthol and 4-nitrophenol (3-methylcholanthrene inducible substrates of glucuronyltransferase, GT 1) was found to be deficient in freshly prepared untreated "native" microsomes from streptozotocin-induced diabetic male rats. The defect was not observed in female rats. Moreover, the glucuronidation of 1-naphthol and 4-nitrophenol was higher in "native" microsomes from male control rats than in those from female controls. This sex difference in the glucuronidation of the GT 1 substrates was abolished by detergent activation of the transferase enzyme in vitro. Streptozotocin treatment did not alter the glucuronidation of paracetamol or phenolphthalein (phenobarbitone inducible substrates for GT 2). This diabetes-induced defect in the glucuronidation of GT 1 substrates was abolished by insulin treatment of the animals and was diminished or completely abolished by detergent activation of the transferase enzyme in vitro. Increased membrane constraint is proposed as the mechanism responsible for the transferase defect. 3-Methylcholanthrene induction abolished the streptozotocin-induced defect in 4-nitrophenol glucuronidation, whereas phenobarbitone did not. This is attributed to the differential effect of these inducers on the microsomal membrane.
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38
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Cook DE, Jackson JD, Past MR, Lang CM, Bullock LP. Drug metabolism in spontaneously diabetic guinea pigs. EXPERIENTIA 1984; 40:840-1. [PMID: 6381086 DOI: 10.1007/bf01951983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Both sexes of spontaneously diabetic guinea pigs exhibit hyperinsulinemia (greater than 4-fold normal). This diabetic state is associated with the inhibition of hepatic drug metabolism in males but not females.
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