Synthesis in the rat

Schmidt, C.J., and Taylor, V.L. Acute effects of methylenedioxymethamphetamine (MDMA) on 5-HT synthesis in the rat brain. 

Tohyama, Y., F. Yamane, M. Fikre-Merid, P. Blier, and M. Diksic. Effects of Serotine Receptors Agonists, TFMPP and CGS12066B, on Regional Serotonin Synthesis in the Rat Brain An Autoradiographic Study. Journal of Neurochemistry 80, no. 

Cell Proliferation. Increased liver weight is a typical response in rodents exposed to DEHP and other peroxisome proliferators. This response is largely due to a transient increase in replicative DNA synthesis and cell division. Although considered a weak inducer of cell proliferation, DEHP causes an almost immediate increase in cell division in rats and mice (Busser and Lutz 1987 Smith-Oliver and Butterworth 1987). A single dose of 664 mg/kg DEHP produced a significant increase in DNA synthesis in the rat liver, as indicated by the incorporation of radioactive thymidine into polynucleotides during the first 24 hours (Busser and Lutz 1987). In mice, a dose of 500 mg/kg stimulated mitosis within 24 hours of... 

Diet or exercise had no effect on carcass cholesterol concentration in Fischer 344 rats fed a hypercholesterolemic diet (71). However, total carcass cholesterol tended to be lower in exercised rats than in sedentary rats. Carcass cholesterol concentration was similar between exercised and sedentary rats, but the body weights of sedentary rats were higher. Both sedentary and exercised rats fed the hypercholesterolemic diet had equivalent food, and hence cholesterol intakes. These data suggest that exercise increases cholesterol excretion and/or degradation, or decreases cholesterol synthesis in the rat. 

Conney AH, Miller EC, Miller JA. 1956. The metabolism of methylated aminoazo dyes. V. Evidence for induction of enzyme synthesis in the rat by 3-methyl-cholanthrene. Cancer Res. 16 450-59... 

McLean, P., Reid, E., and Gurney, M. W., Effect of azo-dye carcinogenesis on enzymes concerned with urea synthesis in the rat. Biochem. J. 91, 464-473 (1964). McLean, P., and Rossi, F., Changes in the activities of urea-cycle enzymes after the administration of carbon tetrachloride. Biochem. J. 91, 261-270 (1964). McMurray, W. C., Mohyuddin, F., Bayer, S. M., and Rathbun, J. C., Citrul-linuria a disorder of amino acid metabolism associated with mental retardation. Int. Copenhagen Congr. Sci. Study Meat. Retard., Proc. 3rd 1, 117 (1964). McMurray, W. C., Rathbun, J. C., Mohyuddin, F., and Koegler, S. J., Citrul-linuria. Pediatrics 32, 347-357 (1963). 

Lu SC, Ge J, Kuhlenkamp J, Kaplowitz N (1992) Insulin and glucocorticoid dependence of hepatic y-glutamylcysteine synthetase and GSH synthesis in the rat studies in cultured hepatocytes and in vivo. J Clin Inv 90 524-532... 

Price, R. J., Evans, J. G., and Lake, B. G. (1992). Comparison of the effects of nafenopin on hepatic peroxisome proliferation and repUcative DNA synthesis in the rat and Syrian hamster. Food Chem Toxicol 30, 937-944. 

Spranger, M., Lindholm, D., Bandtlow, C., Heumann, R., Gnahn, H., Naher-Noe, M. and Thoenen, H. (1990) Regulation of nerve growth factor (NGF) synthesis in the rat central nervous system comparison between the effects of interleukin-1 and various growth factors in astrocyte cultures and in vivo. Eur. J. Neurosci. 2 69-76. 

The natural response to lowered levels of plasma thyroid hormones is for TSH production to increase with rapid growth of the thyroid gland and increased thyroglobu-lin synthesis. In the rat, the thyroid gland becomes desensitized to the effects of more TSH, and the weight of the thyroids stops increasing to the same extent. During this plateau period, some thyroid cells mutate and this leads to the development of thyroid... 

The effect of glucan on survival time and eicosanoid synthesis in the rat faecal peritonitis (LDioq) model has also been assessed . A high dose of glucan decreased survival time from 11.5 0.4 h to 7.3 0.5 h during sepsis... 

Threlfall, G., Taylor, D. M., and Buck, A. T., 1967, Studies of the changes in growth and DNA synthesis in the rat kidney during experimentally induced renal hypertrophy. Am J. 

Levine, R. J., Sato, T. L., and Sjoerdsma, A., 1965, Inhibition of histamine synthesis in the rat by a-hydrazino analog of histidine and 4-bromo-3-hydroxy benzyloxyamine, Biochem. Pharmacol. 14 139-149. 

One study reported by Pal et al. (1975) indicated that lead toxicity impaired vitamin C synthesis in the rat. This finding is of no apparent significance to human nutrition because ascorbic acid is required in the human diet. Fox et al. (1980) have demonstrated that the addition of vitamin C to the diets of Japanese quail protected against high toxic levels of cadmium and decreased the concentration of cadmium in the liver and kidneys as compared to unsupplemented controls fed very low dietary levels of cadmium (Fox et al., 1970). Vitamin C increased the absorption of iron in the animal studies this increase probably was responsible for the observed protection against cadmium. 

The results of Shereshevskaya s (1962, 1963) experiments to study the effect of cortisone on RNA synthesis in the rat liver were somewhat unexpected. She observed inhibition of RNA synthesis in the liver after injections of cortisone except in old rats, in which these injections produced some stimulation of RNA synthesis. However, her experiments were performed on nonadrenalectomized rats, so that injections of the hormone evidently produced too high concentrations in the body. In old rats, the functions of the endocrine glands were weakened, and this led to the stimulatory effect. 

Studies on the development pattern of rat hepatic HMG-CoA reductase levels indicate that the rise which follows weaning from the low reductase levels of suckling to adult daytime levels involves processes other than protein synthesis, and may include relief of in vivo inhibition of the enzyme. The supernatant fraction of suckling rat liver contains such an inhibitor of HMG-CoA reductase which may possibly originate in the milk. Whereas in rat liver the HMG-CoA reductase activity is located exclusively in the microsomal fraction, in the intestinal mucosa the enzymic activity is apparently present in both mitochondrial and microsomal fractions. The properties of the microsomal HMG-CoA reductase enzymes from both tissues have also been compared. Previous in vitro evidence for the existence of a circadian rhythm in the rate of hepatic cholesterol synthesis in the rat has been confirmed in vivo by measuring the conversion of both [ C]acetate and H,0 into non-saponifiable material, which in control experiments contained approximately 70% cholesterol. The circadian changes observed were very similar to changes in the activity of hepatic microsomal HMG-CoA reductase. 

Baylis, C., Mitruka, B., and Deng, A. (1992). Chronic blockade of nitric oxide synthesis in the rat produces systemic hypertension and glomerular damage. J. Clin. Invest. 90, 278-281. 

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