Propionyl-L-carnitine as potential protective agent against adriamycin-induced impairment of fatty acid beta-oxidation in isolated heart mitochondria.

Propionyl-L-carnitine (PLC), a natural short-chain derivative of L-carnitine, has been tested in this study as a potential protective agent against adriamycin (ADR)-induced cardiotoxicity in isolated rat heart myocytes and mitochondria. In cardiac myocytes, ADR (0.5 mM) caused a significant (70%) inhibition of palmitate oxidation, whereas, PLC (5 mM) induced a significant (49%) stimulation. Addition of PLC to ADR-incubated myocytes induced 79% reversal of ADR-induced inhibition of palmitate oxidation. In isolated rat heart mitochondria, ADR produced concentration-dependent inhibition of both palmitoyl-CoA and palmitoyl-carnitine oxidation, while PLC caused a more than 2.5-fold increase in both substrates. Preincubation of mitochondria with 5 mM PLC caused complete reversal of ADR-induced inhibition in the oxidation of both substrates. Also ADR induced concentration-dependent inhibition of CPT I which is parallel to the inhibition of its substrate palmitoyl-CoA. In rat heart slices, ADR induced a significant (65%) decrease in adenosine triphosphate (ATP) and this effect is reduced to 17% only by PLC. Results of this study revealed that ADR induced its cardiotoxicity by inhibition of CPT I and beta-oxidation of long-chain fatty acids with the consequent depletion of ATP in cardiac tissues, and that PLC can be used as a protective agent against ADR-induced cardiotoxicity.

Acute and chronic effects of adriamycin on fatty acid oxidation in isolated cardiac myocytes.

This study was designed to determine if acute (in vitro) or chronic (in vivo) adriamycin inhibits cardiac fatty acid oxidation and if so at what sites in the fatty acid oxidation pathway. In addition, the role of L-carnitine in reversing or preventing this effect was examined. We determined the effects of adriamycin in the presence or absence of L-carnitine on the oxidation of the metabolic substrates [1-14C]palmitate. [1(-14)C] octanoate. [1(-14)C]butyrate, [U-14C]glucose, and [2(-14)C]pyruvate in isolated cardiac myocytes. Acute exposure to adriamycin caused a concentration- and time-dependent inhibition of carnitine palmitoyl transferase 1 (CPT 1) dependent long-chain fatty acid, palmitate, oxidation. Chronic exposure to (18 mg/kg) adriamycin inhibited palmitate oxidation 40% to a similar extent seen in vitro with 0.5 mM adriamycin. Acute or chronic administration of L-carnitine completely abolished the adriamycin-induced inhibition of palmitate oxidation. Interestingly, medium- and short-chain fatty acid oxidation, which are independent of CPT 1, were also inhibited acutely by adriamycin and could be reversed by L-carnitine. In isolated rat heart mitochondria, adriamycin significantly decreased oxidation of the CPT 1 dependent substrate palmitoyl-CoA by 50%. However, the oxidation of a non-CPT 1 dependent substrate palmitoylcarnitine was unaffected by adriamycin except at concentrations greater than 1 mM. These data suggest that after in vitro or in vivo administration, adriamycin, inhibits fatty acid oxidation in part secondary to inhibition of CPT 1 and/or depletion of its substrate, L-carnitine, in cardiac tissue. However, these findings also suggest that L-carnitine plays an additional role in fatty acid oxidation independent of CPT 1 or fatty acid chain length.

Pharmacokinetic profile of methotrexate and 5-fluorouracil in normal and bilharzial-infested mice.

The pharmacokinetics of two commonly used anticancer drugs, methotrexate (MTX) and 5-fluorouracil (5-FU), were investigated in normal and bilharzial-infested mice. Liver glucose-6-phosphatase activity and antipyrine clearance were used as parameters of liver function. Liver glucose-6-phosphatase activity was significantly reduced in bilharzial-infested mice compared with the normal controls. Bilharzial infestation caused a significant reduction in the elimination (beta) and clearance rate (Cl) of antipyrine, whereas its elimination half-life (t1/2 beta) was increased in comparison with the normal controls. A similar pattern was also obtained after MTX and 5-FU administration in bilharzial mice, compared to controls. These results indicate that hepatic bilharziasis causes a significant reduction in the hepatic clearance and elimination of MTX and 5-FU, whereas their areas under the concentration-time curve were significantly increased. These findings may have to be considered in the treatment of bilharzial cancer patients.

Hyperthermic potentiation of cisplatin cytotoxicity on solid Ehrlich carcinoma.

BACKGROUND: Hyperthermia produces marked effects on many biochemical parameters of tumor cells and has been reported to potentiate the effect of many drugs. We therefore evaluated the possible synergistic effect between hyperthermia and cisplatin against solid Ehrlich carcinoma. The study was based on the measurement of some biologic characteristics in tumor tissues, namely: DNA, RNA, and protein content and their rate of synthesis as parameters for nuclear damage; total lipids and cholesterol as parameters for membrane damage; acid-phosphatase and acid-ribonuclease as parameters for lysosomal damage; and tumor volume as a direct parameter for tumor growth. METHODS: Treatment of solid Ehrlich carcinoma by hyperthermia at 43 degrees C for 30 min for 3 successive days produced a 41.5% decrease in tumor volume, as well as a significant decrease in nucleic acids, protein contents and their rate of synthesis, in total lipids and cholesterol, and in acid-phosphatase and acid-ribonuclease. Chemotherapeutic management of the tumor by 5 mg/kg x 3 of cisplatin alone showed a continuous increase in tumor volume but at a lower rate than that of the untreated control. However, when cisplatin was given 1 h prior to hyperthermia, the tumor volume was significantly decreased by 82.6%. RESULTS: The effects observed on all the investigated parameter were intensified when cisplatin was combined with hyperthermia. The results obtained suggest that hyperthermia may enhance the penetration of cisplatin to its target site inside the tumor cells due to a membrane-damaging effect. The enhanced lethality of cisplatin on tumor cells may also be due to the inhibition of DNA repair processes by hyperthermia.

Distribution and toxicity of 5-fluorouracil after intraperitoneal and anal submucosal administration.

The correlation of 5-fluorouracil (5-FU) distribution and its toxicity had been investigated in Albino rats. H3-5-FU was administrated either by intraperitoneal (I.P.) or anal submucosal (A.sm.) route. 5-FU was promptly distributed in different organs with marked accumulation in the pelvic area after A.sm. and in liver and kidney after I.P. administration. Acute toxicity (L.D. 50) was stronger after I.P. (63 mg/kg compared with 80 mg/kg after A.sm.). Side effects expressed in elevation of transaminase and alkaline phosphatase and increase in liver tissue glucose-6-phosphatase and total white blood count were much pronounced after I.P. administration. The results suggest the possibility of using A.sm. route for administration.

Effects of jurak smoke condensate on enzyme activity of the mouse.

The effect of jurak smokes condensate on the activities of alkaline phosphatase, gluoce-6-phosphatase, 5'-nucleotidase, and cholinesterase of mouse liver and small intestine was investigated. Jurak smoke condesate was administered orally by stomach tube five times weekly over a three-month period. Fifteen animals were used at 1, 2, and 3 months after the start of the administration, with 5 animals killed on days 1, 5, and 9, and the liver and small intestine removed for enzyme assays. The activities of all four enzymes, which are known to be sensitive to toxic agents, were significantly affected. These results indicate that the low content of tobacco leaves in jurak paste and the filtration of the smoke by water in the sheesha reservoir are not sufficient to make the smoke inhaled by smokers risk free.

Potentiation of therapeutic effect of methanesulphonate and protection against its organ cytotoxicity by vitamin C in Ehrlich ascites carcinoma bearing mice.

The effect of vitamin C upon the therapeutic index and side effects produced by methanesulfonate of aminoglycols (drug 864T, NSC 140117) had been evaluated in a laboratory system. The antitumor action of 864T, vitamin C and their combination were evaluated in Ehrlich ascites carcinoma (EAC) cells in vivo. Tissue toxicity was assessed using liver and intestinal DNA, RNA, protein contents and their synthesis as parameters. In addition, G-6-pase, 5-Nase and Alk, pase activity levels in both tissues were also measured. Drug 864T (200 mg/kg) produced 50 percent long-term survivors in tumor bearing mice in addition to 10 percent early mortality while in combination with vitamin C (250 mg/kg x 6), there was 80 percent long term survivors with no mortality related to drug toxicity. No toxicity, in all the parameters used, was observed when 864T was given in combination with vitamin C. Drug 864T alone produced a significant decrease in protein content of both liver and intestinal tissue while in combination with vitamin C normal levels were maintained. In addition, all the parameters used were either elevated or decreased by 864T treatment and returned to normal levels in combination with vitamin C. This study proved that vitamin C may be useful not only to potentiate the effect of anticancer drug 864T on the Ehrlich ascites carcinoma but also to antagonize the side effects of the drug.

Escherichia coli infection of the urinary bladder: induction of tumours in rats receiving nitrosamine precursors and augmentation of bladder carcinogenesis by N-nitrosobutyl (4-hydroxybutyl)amine.

Experimental introduction of Escherichia coli type 04 into the subserosa of the urinary bladder of female Fischer 344 rats produced chronic bacterial infection in more than 90% of animals. Groups of rats with bacterial infection were given sodium nitrate and either piperazine (Group 1) or dibutylamine (Group 2) in the drinking-water. Control, noninfected animals received nitrate and either piperazine (Group 3) or dibutylamine (Group 4). At 40 weeks, transitional-cell carcinomas of the bladder were detected in 9/30 rats in Group 1 compared to 0/34 in Group 3 (p less than 0.0005), and in 11/34 rats in Group 2 compared to 0/32 in Group 4 (p less than 0.0003). Early changes were examined by scanning and transmission electron microscopy as well as autoradiography. Preneoplastic liver foci were detected in infected groups of animals receiving amine and nitrate, indicating reabsorption of the carcinogen synthesized in situ to induce distant organ transformation. In another experiment, E. coli infection augmented bladder carcinogenesis by N-nitrosobutyl(4-hydroxybutyl)amine (NBHBA), as indicated by earlier appearance of bladder tumours (six weeks compared to nine weeks) and, after 25 weeks, higher incidences of transitional-cell carcinomas (41/46 compared to 39/53, p less than 0.05), squamous metaplasia (43% compared to 9%, p less than 0.0001), glandular metaplasia (26% compared to 13%, p less than 0.05) and muscle invasion (30% compared to 11%, p less than 0.01) in the E. coli-infected group receiving carcinogen compared to the noninfected group receiving carcinogen, respectively. These results indicate that bacterial infection of the urinary bladder may play a major role in bladder carcinogenesis, both by helping in-situ nitrosamine synthesis and by augmenting carcinogenesis by nitrosamines.

Anal submucosal injection: a new route for drug administration in pelvic malignancies. Part I. Experimental study of misonidazole distribution in serum and tissues, with special reference to urinary bladder. Preliminary report.

The anal and oral administration routes were compared in 30 rats to study the distribution of misonidazole, a radiation sensitizer, in the serum and tissues with special reference to the urinary bladder. 14C-labelled misonidazole was administered in a dose of 0.2 ml water/100 gm body weight containing 1 mu Ci misonidazole. The dose was given orally by stomach tube in 15 rats, and was injected in the submucosa of the anal canal in another 15. Animals were then killed after 15, 30, 60, or 120 minutes or after 24 hours. Organs were dissected, and radioactivity was determined in each by the internal standard method. The study has shown that the highest drug concentration in the bladder tissue relative to the serum was achieved with the anal submucosal route. Its level was eight and five times that of the serum 15 and 30 minutes after administration, respectively, in contrast to the oral route in which the drug concentration was one-quarter and equal to the serum level at the same time intervals. The anal route would thus provide the adequate channel required for misonidazole to promote radiation responsiveness in bladder carcinoma.

Serum estrogen level in Egyptian breast cancer patients.

In menstruating 20-29 year old breast cancer patients, the total estrogen level showed a significant increase in the early follicular phase compared to normal healthy subjects. Such a difference was not observed in 30-45 year-old patients. A nonsignificant decrease was observed in the estradiol level of premenopausal breast cancer patients compared to normal healthy subjects. However, in postmenopausal breast cancer patients, the total estrogen level as well as the estradiol level showed a significant increase compared to that of normal healthy subjects.

Sensitive fluorimetry of adenine-containing compounds with high-performance liquid chromatography.

A definitive method to determine adenine compounds simultaneously was established by introducing a new fluorescent reagent into high-performance liquid chromatography. Bromoacetaldehyde was the best reagent among the haloacetaldehydes examined. A quantitative reaction was obtained even for unstable ADP and ATP. A high resolution of adenine nucleotides was obtained using a column of Hitachi gel No. 3012-N. The method was applied to the measurement of cyclic AMP in urine, and ADP and ATP in brain and blood. Further, the sensitivity of the method was increased by a new fluorescence spectrophotometer constructed for micro-HPLC. Femtomole amounts of the adenine nucleotides were clearly separated.

Effect of new anticancer methanesulfonates on different biochemical parameters of mouse liver.

The comparative effect to two chemically related new synthesized anticancer drugs namely 3,3'-(methylimino) di(l-propanol)dimethanesulfonate(ester)diphenyl disulfonate, No. 838 D (NSC, 140-115) and 3,3' iminodi-l-propanol dimethanesulfonate(ester)p-toluene disulfonate, No. 864 T (NSC, 140-117), on liver DNA, RNA, lipids and glucose-6-phosphatase, after single 100 mg i.p. injection was studied. Both drugs significantly reduced DNA, RNA and total lipid content on day one and two after administration. Normal levels were regained on day three. Both drugs did not cause a decrease in glucose-6-phosphatase activity level, on the contrary, the enzyme was significantly elevated on day three after administration. The present results demonstrate that these drugs induce no severe or permanent damage to hepatic cells in the administered dose.

Intravesical administration of misonidazole in bladder carcinoma.

Using 11C labelled material, the diffusion of the hypoxic cell sensitizer misonidazole was tested in 19 patients with carcinoma of the bladder following its intravesical administration. Increasing concentration gradients were tested. Evidence was provided that a 20 ml solution containing 200 mmol/l of misonidazole is followed by high concentrations of the drug in the superficial as well as in deep parts of the tumour. The corresponding serum concentration was extremely low. It was concluded that this route of administration provides high local concentrations of the drug that may result in a significant therapeutic enhancement if utilized as an adjuvant to external irradiation.

A study on the etiological factors of bilharzial bladder cancer in Egypt. 6. The possible role of urinary bacteria.

A correlation was obtained between a positive nitrite test in urine and the severity of urinary bacterial infection. Bacteria isolated from the urine of bilharzial or bladder cancer patients were found to be rich in nitrate reductase activity. "Escherichia coli" was the most common microorganism isolated from these specimens. Urine and several urinary constituents activate bacterial nitrate reductase. beta-Glucuronidase activity in the urine of patients with chronic "Schistosoma haematobium" infection and bladder cancer was measured and shown to be significantly greater than that of urine of normal control subjects. Urinary bacterial infection was shown to be the source of the increased urinary level of enzyme activity at pH 7.0.

A study on the etiological factors of bilharzial bladder cancer in Egypt: 4. beta-carotene and vitamin A level in serum.

The possible role of vitamin A in the pathogenesis of bilharzial bladder cancer among Egyptians, particularly as it relates to the histopathologic tumor type, was investigated. Bilharzial patients and bladder cancer patients with squamous cell carcinoma, the most prevalent type in Egypt, showed significantly lower levels of vitamin A than normal male subjects. In contrast bladder cancer patients with transitional cell carcinoma had levels that were not significantly different from normal male subjects. The possible role of vitamin A in the etiology of bilharzial bladder cancer is discussed.

A study on the etiological factors of bilharzial bladder cancer in Egypt: 5-urinary nitrite in a rural population.

Urinary nitrite was present in 5.6% of 2379 individuals from a rural population infested with "Schistosoma haematobium". A higher frequency was observed in symptomatic patients with active bilharzial cystitis (25%) and patients with bladder cancer associated with schistosomiasis (66.2%); conversely, urinary nitrite was absent in normal urban individuals. The frequency of urinary nitrite was higher in females (6.4%) than males (4.6%), and was more frequent in adults than extremes of age. The presence of urinary nitrite was associated with urinary infection and was commonly accompanied by cellular atypia in urine, in the form of dysplasia. Under these circumstances, carcinogenic nitrosamines are liable to be produced in the bladder from urinary nitrite and amines. These observation support the possible role of urinary bacterial infection, commonly associated with bilharzial cystitis, in bladder carcinogenesis.

Misonidazole in the preoperative and radical radiotherapy of bladder cancer.

Measurement of intercapillary distances suggests the presence of significant cell hypoxia in Bilharzial bladder cancer. This tumor seems to be capable of reoxygenation in view of the existence of a correlation between prognosis and immediate tumor shrinkage after irradiation. Two programs are presented: 1) Use of misonidazole with concentrated preoperative irradiation where the reoxygenation properties are not used fully. A prospective randomized study is presented whereby cystectomy alone is compared with cystectomy plus preoperative irradiation (6.5 Gy X 2F/1 week) with or without misonidazole. the drug is given either orally (in two doses 3 g/m2 each given 3.5 hours prior to each fraction; blood levels: 90-110 micrograms/ml) or intravesically. The intravesical administration is designed in the light of penetration studies and seems to have the advantage of the complete lack of systemic drug toxicity. Twenty-eight patients were included in this study and no drug toxicity was recorded. A second preoperative irradiation study is presented whereby cystectomy alone is compared with cystectomy plus preoperative irradiation (4.0 Gy X 5F) with or without misonidazole in individual doses of 2 g/m2. 2) Two radical radiotherapy regimes are presented. One protocol involves a split course (SC) protracted regime making full use of spontaneous reoxygenation. The drug is given in 0.5 g/m2 daily doses (total dose 14 g/m2 spread over 61 days, blood level: 15-20 micrograms/ml). A second protocol involves hyperfractionation stimulating continuous low-dose-rate irradiation. Higher blood levels are attained (60-80 micrograms/ml) after daily doses of 2 g/m2 (total dose: 14 g/m2 spread over 35 days). In a phase II study using SC technic, reversible grade 1 peripheral neuropathy was encountered in 5 of 22 patients. Complete tumor regression 3 months after irradiation was achieved in 18 of 22 patients with 3T tumors. No neuropathy was encountered in four patients subjected to the HF regimen who also showed complete tumor regression.