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PubMed1997

[Effects of bFGF on succinate dehydrogenase level and oxygen consumption of skin flap in rats].

To investigate the effects of basic fibroblast growth factor (bFGF) on necrosis rate, succinate dehydrogenase level and oxygen consumption of the skin flap, 18 Wistar rats were divided into 2 groups. Caudally based skin flap was raised on the back of each rat. Nine micrograms bFGF or normal saline with heparin was instilled under the flaps respectively after closure of the wounds. After 7 days, the necrosis rate of each wound was measured. The result showed that in bFGF group, the average necrosis rate of skin flap was 18.2%, less than that of the control group (37.14%). Succinate dehydrogenase content and oxygen consumption in bFGF group were higher than those of the corresponding sites in the control group (P < 0.05). It was suggested that the use of bFGF resulted in the decrease rate of necrosis of skin flap, and it maintained higher succinale dehydrogenase level and oxygen consumption. It was concluded that bFGF would probably be valuable for clinical use.

Animals↗
PubMed1978

[Purification of 2 succinic semi-aldehyde reductases from the human brain].

Two succinic semi-aldehyde reductases (A and B) have been purified to electrophoretic homogeneity. Enzyme A, which is a monomer of molecular weight 40,000 +/- 5,000 reduces a wide range of aldehydes and is inhibited by some barbiturates and certain anticonvulsants. Enzyme B, which is a dimer of molecular weight 80,000 +/- 10,000, is very specific for succinic semi-aldehyde and is not inhibited by the aforementioned compounds.

Aldehyde Oxidoreductases↗
PubMed2002

X-ray diffraction and molecular simulation study of the crystalline and liquid states of succinic anhydride.

The crystal structure of succinic anhydride was studied at five temperatures between 100 K and the melting point by single-crystal X-ray diffraction. The temperature dependence of molecular libration tensors was determined. Intermolecular interactions, in particular through unusually close molecule-molecule contacts, are discussed, with a detailed calculation of electrostatic energies. A method for the adaptation of existing crystal force fields to molecular dynamics has been developed; the adapted force field was used to study molecular motion and rotational diffusion with increasing temperature. Equilibration of the crystalline system becomes impossible at a temperature very close to the experimental melting temperature, where a sudden transition to the liquid state occurs, and a partial kinetic picture of the melting process is obtained. After validation of the force field against experimental crystal data, the state equation of the liquid was predicted. Enthalpies of sublimation, melting, and vaporization were calculated. The dynamics of a solution of succinic anhydride in a nonpolar solvent was simulated, for a discussion of the aggregation process leading to demixing and to crystal nucleation.

Journal Article↗
PubMed1991

Disposition of methylprednisolone and its sodium succinate prodrug in vivo and in perfused liver of rats: nonlinear and sequential first-pass elimination.

The disposition of methylprednisolone (MP) and its prodrug succinate ester, methylprednisolone sodium succinate (MS), were examined both in vivo and in situ (perfused livers) in rats. In vivo studies included iv and oral dosing of 10 or 50 mg/kg of MP in both forms, while liver perfusion involved initial perfusate concentrations of 5 and 25 micrograms/mL of either compound. Steroid concentrations were measured by HPLC. In the intact rat, clearance (CL) values of both compounds were high, twice the hepatic plasma flow, and decreased by one-half after the high dose, indicating nonlinear kinetics. The volumes of distribution of MS and MP were essentially constant with dose. Incomplete availability of MP from iv MS (52-55%) and from the oral dose (10%) was found. Sequential first-pass metabolism was investigated in situ. Extensive hepatic extraction of MP (84%) occurred at the low dose, but decreased to 48% at the high dose, supporting in vivo observations of high CL and nonlinearity. Extraction of MS was also high (83%), but MP availability was slight (8%). The MS and MP data were fitted to a sequential first-pass model yielding an average fraction of MS metabolized-to-MP value of 0.22. The prodrug MS and the active metabolite MP thus demonstrate both systemic and hepatic nonlinearity in rats, and the low availability of MP from iv MS was due, in part, to sequential first-pass elimination. This factor is more extensive in rats than in other species.

Animals↗
PubMed2005

In vitro evaluation of biodegradable poly(butylene succinate) as a novel biomaterial.

Poly(butylene succinate) (PBSU) can be easily synthesized by condensation polymerization of the starting materials of succinic acid and butan-1,4-diol. It has good degradability and possesses excellent processability. Due to these advantages, PBSU was first evaluated in the present study for its potential application as a novel biomaterial. The in vitro biocompatibility of the PBSU was evaluated by monitoring proliferation and differentiation of osteoblasts cultured on the PBSU film substrates for different periods. The results showed that the PBSU was biocompatible as the osteoblasts could proliferate and differentiate on the PBSU plates. In addition, the hydrolytic degradation behavior of the PBSU films in the phosphate-buffered saline (PBS) was also investigated and the results suggested that the PBSU degraded in the PBS solution with the same behavior as that of the degradable poly(alpha-hydroxyesters). In addition to the biocompatibility and hydrolytic degradation, some physical properties, including hydrophilicity, and mechanical and thermal properties of the PBSU substrates, were also determined and the results revealed that the PBSU was hydrophilic and ductile with excellent processability. The biocompatibility of the PBSU, together with the advantages of hydrolytic degradability, hydrophilicity, and excellent processability, indicated that PBSU has the potential to be used as a biomaterial for tissue repair. [Diagram: see text] Alkaline phosphate activity of osteoblasts cultured on PBSU and TCPS substrates for different time periods.

Biocompatible Materials↗
PubMed2002

Role of extracellular signal-regulated kinase pathway in RRR-alpha-tocopheryl succinate-induced differentiation of human MDA-MB-435 breast cancer cells.

RRR-alpha-tocopheryl succinate (vitamin E succinate, VES) induces differentiation of human breast cancer cells. Previous studies ruled out transforming growth factor-beta and c-jun N-terminal kinase involvement in VES-induced differentiation but implicated extracellular signal-regulated kinases (ERKs). Here we show that dominant-negative mutants of either mitogen-activated protein kinase kinase (MEK) 1 or ERK1 blocked VES-induced differentiation of MDA-MB-435 cells, as measured by induction of cytokeratin 18 and p21 (Waf1/Cip1) proteins. Blockage of c-jun protein expression using c-jun antisense oligonucleotides or expression of an inducible dominant-negative c-jun mutant protein inhibited VES-induced differentiation. Elevated expression of wild-type c-jun alone was sufficient to induce cellular differentiation. A role for p21 (Waf1/Cip1) is implicated, in that p21 antisense oligomers blocked VES-induced differentiation. In summary, MEK1, ERK1, the transcription factor c-jun, and the cyclin-dependent kinase inhibitor p21 (Waf1/Cip1) play a part in VES-induced differentiation of human MDA-MB-435 breast cancer cells.

Breast Neoplasms↗
PubMed2000

Vitamin E succinate promotes breast cancer tumor dormancy.

BACKGROUND: Vitamin E succinate (VES) is the most potent antitumor analogue of vitamin E. Despite many reports of VES's antitumor activity in vitro, there is little information about its antitumor effects in vivo. MATERIALS AND METHODS: We investigated the effect of VES on the growth of human breast cancer cells in vitro and in vivo. RESULTS: VES decreased cell viability in MDA-MB-231 and MCF-7 human breast cancer cells. Although VES increased apoptosis in MDA-MB-231 cells, it had no effect on apoptosis in MCF-7 cells. The inhibitory effect of VES on cell growth was specific for the intact molecule because a markedly reduced effect was noted when either vitamin E or succinic acid was administered alone. VES inhibited the growth of MDA-MB-231 cells in nude mice. Also, VES was found to inhibit vascular endothelial growth factor (VEGF) gene expression in MDA-MB-231 cells. CONCLUSIONS: VES inhibits the growth of breast cancer cells in vitro and in vivo. This is the first report of VES inhibition of established tumor growth in vivo. The mechanism of VES's in vivo effects may involve inhibition of tumor angiogenesis since VES inhibits VEGF gene expression.

Animals↗
PubMed1998

Expression of the succinate dehydrogenase genes (sdhCAB) from the facultatively anaerobic paenibacillus macerans during aerobic growth

Paenibacillus (formerly Bacillus) macerans is capable of succinate oxidation under oxic conditions and fumarate reduction under anoxic conditions. The reactions are catalyzed by different enzymes, succinate dehydrogenase (Sdh) and fumarate reductase (Frd). The genes encoding Sdh (sdhCAB) were analyzed. The gene products of sdhA and sdhB were similar to the subunits of known Sdh and Frd enzymes. The hydrophobic subunit SdhC showed close sequence similarity to the class of Sdh/Frd enzymes containing diheme cytochrome b. From the sdhCAB gene cluster two transcripts were produced, one comprising sdhCAB, the other sdhAB. The transcripts were found only during aerobic growth, and the amount was directly proportional to Sdh activity, but inversely proportional to Frd activity.

Journal Article↗
PubMed2004

alpha-Tocopheryl succinate sensitizes established tumors to vaccination with nonmatured dendritic cells.

PURPOSE: Dendritic cells (DCs) are considered potential candidates for cancer immunotherapy due to their ability to process and present antigens to T cells and stimulate immune responses. However, DC-based vaccines have exhibited minimal effectiveness against established tumors in mice and human cancer patients. The use of appropriate adjuvants can enhance the efficacy of DC-based cancer vaccines in treating established tumors. METHODS: In this study we have employed alpha-tocopheryl succinate (alpha-TOS), a nontoxic esterified analogue of vitamin E, as an adjuvant to enhance the effectiveness of DC vaccines in treating established murine Lewis lung (3LL) carcinomas. RESULTS: We demonstrate that locally or systemically administered alpha-TOS in combination with nonmatured DCs injected intratumorally (i.t.) or subcutaneously (s.c.) significantly inhibits the growth of preestablished 10-day tumors (mean tumor volume of 77.5 +/- 17.8 mm3 on day 30 post-tumor injection) as compared to alpha-TOS alone (mean tumor volume of 471 +/- 68 mm3 on day 30 post-tumor injection). Additionally, the adjuvant effect of alpha-TOS was superior to that of cyclophosphamide (CTX). The mean tumor volume on day 28 post-tumor injection in mice treated with CTX+DCs was 611 +/- 94 mm3 as compared to 105 +/- 36 mm3 in mice treated with alpha-TOS+DCs. Analysis of purified T lymphocytes from mice treated with alpha-TOS+DC revealed significantly increased secretion of IFN-gamma as compared to T cells from the various control groups. CONCLUSION: This study demonstrates the potential usefulness of alpha-tocopheryl succinate, an agent nontoxic to normal cell types, as an adjuvant to augment the effectiveness of DC-based vaccines in treating established tumors.

Adjuvants, Immunologic↗
PubMed1982

Successful renal transplantation in a patient with anaphylactic reaction to Solu-Medrol (methylprednisolone sodium succinate).

Following the intravenous infusion of Solu-Medrol (methylprednisolone sodium succinate), anaphylactic shock developed in a 41 year old man on two consecutive occasions, six weeks apart. Intracutaneous testing with different components of he Solu-Medrol Mix-O-Vial demonstrated that the patient was allergic to methylprednisolone sodium succinate but not to other ingredients. In view of the recent increase in the popularity of steroid pulse therapy, we believe that all clinicians should be aware of this unusual and potentially fatal reaction to Solu-Medrol.

Adult↗
PubMed1982

Effects of Q metabolites and related compounds on mitochondrial succinate and NADH oxidase systems.

The effects of Q metabolites (Q acid-I, Q acid-II) and related compounds (dihydro Q acid-I, dehydro Q acid-II, QS-n, and their esters) on mitochondrial succinate and NADH oxidase systems were investigated. The activity restoring succinate oxidation in acetone-treated beef heart mitochondria was found to decrease with descending order of carbon number (n) of the side chain of the Q metabolites; activity was restored with Q acid-I (n = 7) to one-third as much as that with Q-7 and Q-10, but Q acid-II (n = 5) did not restore any activity. Of the related compounds with a carboxyalkyl group (QS-n), QS-16-QS-18 (n = 16-18) were found to be most active, and their activities were also correlated with n. The relationship between the restoration of activity and the partition coefficient was considered. NADH oxidation in pentane-treated beef heart submitochondrial particles could be restored with esters of low molecular weight quinones to the same extent as with Q-10, but not with the metabolites.

Animals↗
PubMed1976

Separation and properties of the NAD-linked and NADP-linked isozymes of succinic semialdehyde dehydrogenase in Euglena gracilis z.

Euglena gracilis z contained two succinic semialdehyde dehydrogenases (EC 1.2.1.16), one requiring NAD and the other NADP, and these isozymes were separated from each other and partially purified. The NAD-linked isozyme was relatively stable on storage at 5 degrees C whereas the NADP-linked one was extremely unstable unless 30% glycerol or ethyleneglycol was added. The optimum pH was 8.7 and optimum temperature 35-45 degrees C for both isozymes. They were inhibited by Zn2+ and activated, particularly the NAD-linked enzyme, by K+. Sulfhydryl reagents activated both isozymes. The Km values for succinic semialdehyde were 1.66 - 10(-4) M with the NAD-linked isozyme and 1.06 - 10(-3) M with the NADP-linked one. The NADP-linked isozyme was induced by glutamate while the NAD-linked one was not. Probable roles of these isozymes in the physiology of Euglena gracilis are discussed.

Aldehyde Oxidoreductases↗
PubMed1996

Inactivation of an NADPH-dependent succinic semialdehyde reductase by o-phthalaldehyde.

Incubation of an NADPH-dependent succinic semi-aldehyde reductase from bovine brain with o-phthalaldehyde resulted in a time-dependent loss of enzyme activity. The inactivation followed pseudo first-order kinetics with the second-order rate constant of 28 M(-1) s(-1). The inactivation was prevented by preincubation of the enzymes with NADPH, but not by succinic semialdehyde. There was a linear relationship between isoindole formation and the loss of enzyme activity. Spectrophotometric studies indicated that complete inactivation of the enzyme resulted from the formation of one isoindole derivative per molecule of enzyme, which was formed from the reaction of cysteine and lysine residues with o-phthalaldehyde at or near the enzyme active site.

Animals↗
PubMed1983

The effect of oral estriol succinate therapy on the endometrial morphology in postmenopausal women: the significance of fractionation of the dose.

Postmenopausal women were given estriol succinate orally in a daily dose of 4 mg X 2 for 14 days or 4 mg X 2, 8 mg X 1 and 2 mg in the morning + 2 mg at noon + 4 mg in the evening for 4 wk. Each group consisted of 4 women. The effect of the estrogen treatment was estimated by the endometrial curettage samples taken both before and after the hormone treatment. The curettage samples were studied by both light and electron microscopy. The results showed that a treatment period of 4 wk was necessary to obtain any effect. When 8 mg of estriol succinate was given in a single dose only a slight effect was obtained on the endometrium but when the same dose was divided in 2 daily 4 mg parts, the endometrium showed clearly proliferative changes. Thus estriol is able to produce the same endometrial effect as estradiol. Ultrastructurally the hormone treatment caused an increase in the cytoplasm of the endometrial epithelial cells. Also, whorls of cytoplasmic microfilaments often appeared near the nucleus of the cells.

Aged↗
PubMed1991

Controlled intraoral delivery of hydrocortisone sodium succinate.

Controlled release of hydrocortisone sodium succinate from a device consisting of a drug containing a core of polymethyl methacrylate was achieved by the use of a design incorporating impermeable barriers to drug diffusion and the use of a semipermeable membrane. Initial in vivo study showed sustained intraoral delivery of hydrocortisone sodium succinate during a 6-day period.

Administration, Oral↗
PubMed1981

Bronchospasm caused by intravenous hydrocortisone sodium succinate (Solu-Cortef) in aspirin-sensitive asthmatics.

Eleven patients with intrinsic asthma and aspirin sensitivity were challenged with intravenous hydrocortisone sodium succinate (Solu-Cortef; the Upjohn Co., Kalamazoo, Mich.). Three patients showed definite evidence of bronchospasm, which was easily reversed by subcutaneous administration of epinephrine. Evidence is presented which suggests that this reaction was not caused by other constituents of the preparation but rather was caused by Solu-Cortef alone. No atopy was demonstrated in the group as a whole, and the reaction observed was probably nonallergic in nature. We suggest the replacement of intravenous hydrocortisone sodium succinate with dexamethasone in the treatment of such a population.

Adult↗
PubMedDate not supplied

In vivo effect of acetyl-L-carnitine on succinate oxidation, adenine nucleotide pool and lipid composition of synaptic and non-synaptic mitochondria from cerebral hemispheres of senescent rats.

The effect of acetyl-L-carnitine on succinate oxidation, adenine nucleotide pool and lipid composition of synaptic and 'free', non-synaptic, mitochondria in cerebral hemispheres of senescent rats has been studied. Fisher rats (24- or 28-month-old) were treated with acetyl-L-carnitine (300 mg/kg body wt., intraperitoneally (i.p.)) 3 h before being killed. Oxygen consumption was measured using succinate as a substrate; adenine nucleotides and lipids were analyzed by high performance liquid chromatography (HPLC). Acetyl-L-carnitine reverses, in synaptic mitochondria, the age-related decrease in the respiratory control ratio due to a higher state 4 respiration rate. Administration of acetyl-L-carnitine to senescent rats does not affect the total adenine nucleotide pool of synaptic and non-synaptic mitochondria which was unchanged with age. Finally, pretreatment of senescent rats with acetyl-L-carnitine brings the cholesterol and phospholipid contents of synaptic mitochondria, reduced in senescent rats, to the adult level; pretreatment of adult rats has no such effect. Altogether these results suggest that acetyl-L-carnitine is able to reverse age-related deficits of brain mitochondria.

Journal Article↗
PubMed1994

2-Methylbutyryl-CoA: succinate acyl-CoA transferase activity and function in Ascaris suum muscle.

A branched-chain acyl-CoA transferase activity which transfers coenzyme A from either 2-methylbutyryl or 2-methylvaleryl-CoA to succinate is present in the muscle mitochondria from the intestinal nematode, Ascaris suum. Its physiological function is discussed. This activity appears to differ from the previously described acetyl-CoA: propionate and propionyl-CoA:succinate acyl-CoA transferases on the basis of heat stability, substrate specificity and the requirement of a "factor" from boiled Ascaris mitochondria for optimal activity of only the branched-chain acyl-CoA transferase. The "factor" has been recovered from HPLC and some of its properties examined. It could not be replaced by a crude soluble fraction from rat liver mitochondria, or by adenine, guanine or inosine di- or triphosphates. Activity was lost upon ashing, but was not affected by treatment with either pepsin or chymotrypsin.

Animals↗