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Biomedical subjects

A Perin

Publications and source records attributed to A Perin.

At least 73 records · Page 4Linked to original sources
PubMed1985

Regulation of diamine oxidase expression by beta 2-adrenoceptors in normal and hypertrophic rat kidney.

The administration of preferential adrenergic receptor antagonists to uninephrectomized rats revealed the beta 2-adrenergic mediation in diamine oxidase activity increase that occurs in the remaining kidney undergoing compensatory hypertrophy. In fact, beta 1, beta 2- or beta 2, but not alpha 1-, alpha 2-, or beta 1-receptor-blocking agents prevented this enzyme enhancement. Further studies with adrenoceptor agonists, such as epinephrine (alpha 1, alpha 2, beta 1, beta 2), isoproterenol (beta 1, beta 2) or terbutaline (beta 2) showed that also in normal rat kidney diamine oxidase activity is under the control of catecholamine-beta 2-receptors through a mechanism that involves new synthesis of mRNA and protein. Theophylline, an inhibitor of phosphodiesterase, or forskolin, an activator of adenyl cyclase, increased diamine oxidase activity as does epinephrine or nephrectomy. Thus, catecholamine-triggered beta 2-receptors coupled to adenyl cyclase are involved in the regulation of diamine oxidase activity in normal and hypertrophic rat kidney.

Adrenergic Agonists↗
PubMed1984

Stimulation of hepatic and renal diamine oxidase activity after acute ethanol administration.

The effect of a single administration of ethanol (2 g/kg body weight) on hepatic and renal diamine oxidase activity was studied in fasted rats. Diamine oxidase activity significantly increased in liver and kidney 6 h after ethanol intubation. Pyrazole (an inhibitor of alcohol dehydrogenase), cycloheximide or actinomycin D (inhibitors of macromolecular syntheses), as well as prior adrenalectomy, prevented the ethanol-induced stimulation of diamine oxidase in the liver, but not in the kidney. The results demonstrated that the enhancement of diamine oxidase activity in the liver was due to an enzyme induction mediated by alcohol metabolism as well as by adrenals. In contrast, the stimulation of diamine oxidase activity in the kidney did not depend on synthesis of new enzyme molecules and was not mediated by ethanol metabolism or adrenal hormones.

Amine Oxidase (Copper-Containing)↗
PubMed1983

Polyamine levels and diamine oxidase activity in hypertrophic heart of spontaneously hypertensive rats and of rats treated with isoproterenol.

Polyamine levels and diamine oxidase (EC 1.4.3.6) activity were studied in hypertrophic heart of spontaneously hypertensive rats as well as in the heart of Wistar rats during the development and regression of cardiac hypertrophy induced by isoproterenol administration. In spontaneously hypertensive rats, putrescine content and diamine oxidase activity were higher than those found in normotensive Kyoto-Wistar control rats. During the development of cardiac hypertrophy induced by isoproterenol, there was an increase in polyamine content and diamine oxidase activity. The administration of cycloheximide or actinomycin D prevented the increase in diamine oxidase activity during the first 24 h after isoproterenol administration, demonstrating that the rise in diamine oxidase activity was due to synthesis of new enzyme. Following the cessation of isoproterenol treatment, cardiac hypertrophy regressed and polyamine levels and diamine oxidase activity diminished toward control values. The administration of aminoguanidine to isoproterenol-treated rats caused in the heart an inhibition of diamine oxidase activity that led to an increase in putrescine level beyond the values found in animals given isoproterenol alone. The results suggest that the enhancement of diamine oxidase activity plays a role in the regulation of putrescine level in hypertrophic heart.

Amine Oxidase (Copper-Containing)↗
PubMed1982

Diamine oxidase activity induction in regenerating rat liver.

The synthesis and turnover of diamine oxidase (EC 1.4.3.6) activity was studied in regenerating rat liver after partial hepatectomy using inhibitors of protein and RNA syntheses. The administration to animals of cycloheximide or actinomycin D prevented the increase in diamine oxidase activity normally observed during the first hours after hepatectomy. The study of the turnover rate of diamine oxidase with cycloheximide demonstrated that the half-life of this enzyme was about 15 h in normal and regenerating liver. These results suggest that the rise in diamine oxidase activity in regenerating rat liver was due to the synthesis of new enzyme rather than to a lengthening of its turnover.

Amine Oxidase (Copper-Containing)↗
PubMed1982

Induction of diamine oxidase activity in rat kidney during compensatory hypertrophy.

Diamine oxidase (EC 1.4.3.6) activity, measured as [14C]delta1 -pyrroline formation from [14C]putrescine, was studied in homogenates of rat kidney during compensatory hypertrophy after unilateral nephrectomy. Acetaldehyde and to a lesser degree phenobarbital, at concentrations which did not modify the activity of a preparation of hog kidney diamine oxidase, increased delta1 -pyrroline formation in kidney homogenate, which suggests that aldehyde-metabolizing enzymes present in this tissue may interfere with the yield of delta1 -pyrroline formation and that the use of acetaldehyde may give better information on kidney diamine oxidase activity. Other inhibitors of aldehyde-metabolizing enzymes such as chloral hydrate, disulfiram, and pyrazole cannot be used for diamine oxidase determination since they stimulated or depressed this enzyme activity. In rat kidney undergoing compensatory hypertrophy the levels of putrescine, spermidine, and spermine increased rapidly and were followed by an increase in diamine oxidase activity that presented a first peak on day 2 and a second peak on day 6. The administration of cycloheximide or actinomycin D to nephrectomized rates prevented the increase in diamine oxidase activity. The study of the turnover rate of diamine oxidase with cycloheximide demonstrated that the half-life of this enzyme was about 14 h in normal and hypertrophic kidney. The results suggest that the increase in diamine oxidase activity in renal hypertrophy was due to the synthesis of new enzymes rather than to slowing of its degradation.

Acetaldehyde↗
PubMed1981

Diamine oxidase activity in regenerating rat liver and in 4-dimethylaminoazobenzene-induced and Yoshida AH 130 hepatomas.

Diamine oxidase (EC 1.4.3.6) activity, measured as delta 1-[14C]pyrroline formation from [14C]putrescine, was studied in homogenates of regenerating liver and of 4-dimethylaminoazobenzene-induced by Yoshida AH 130 hepatomas of rat. The addition in the incubation medium of acetaldehyde increased delta 1-pyrroline formation in normal and regenerating liver that contained aldehyde dehydrogenase but not in hepatomas where this enzymatic activity was very low or virtually absent. Acetaldehyde did not modify the activity of a preparation of hog kidney diamine oxidase, while chloral hydrate and disulfiram, respectively, enhanced and depressed the activity of this enzyme. These results suggest that aldehyde-metabolizing enzymes present in homogenate may interfere with the amount of delta 1-pyrroline formation and that the use of acetaldehyde may give better information on tissue diamine oxidase activity. Diamine oxidase activity, which was very low in normal liver, increased rapidly in regenerating liver and reached maximum values between 16 and 48 hr after hepatectomy. A large increase in diamine oxidase activity, as compared to the values of normal liver, was also observed in 4-dimethylaminoazobenzene and Yoshida ascites hepatomas.

Acetaldehyde↗
PubMed1978

Changes in polyamine levels and protein synthesis rate during rat liver carcinogenesis induced by 4-dimethylaminoazobenzene.

The concentrations of putrescine, spermidine, and spermine in liver of rats fed on 4-dimethylaminoazobenzene and in the resultant hepatomas were found to be significantly higher than were those observed in normal liver from rats of the same strain, sex, and age. These modifications were due to the carcinogen and not to the special low-riboflavin diet used to obtain the carcinogenic effect of 4-dimethylaminoazobenzene. The first change observed during liver carcinogenesis was the early increase in the putrescine level, followed by an increase of spermidine and spermine, which reached maximum levels in growing hepatomas. A significant increase of urinary polyamines was also observed in tumor-bearing rats. Experiments on leucine incorporation into proteins of tissue slices, which were obtained from the same tissues on which polyamine determinations were carried out, showed that in rat liver carcinogenesis the rate of protein synthesis was well correlated with the polyamine levels. These results suggest that polyamines may play a role in the process of carcinogenesis and in tumor protein synthesis in vivo.

Animals↗
PubMed1978

Carcinostatic effect of aliphatic aldehydes and aldehyde dehydrogenase activity in Ehrlich carcinoma, Sarcoma 180, and Yoshida AH 130 hepatoma.

The antitumor activity of 2,3-dihydroxybutyraldehyde on Ehrlich carcinoma, Sarcoma 180, and Yoshida AH 130 hepatoma, as well as the aldehyde dehydrogenase activity in these tumors, was studied. 2,3-Dihydroxybutyraldehyde at nontoxic doses (500 mg/kg body weight i.p. daily for 7 days) slowed down the growth of solid and ascites tumors in mice. The treatment completely prevented the development of Yoshida ascites hepatoma in several rats. 2,3-Dihydroxybutyraldehyde, although it did not influence the growth of Ehrlich carcinoma transplanted in the brain of mice, significantly decreased in the lungs of these animals the number of viable tumour cells that derived from the primary tumor. All the tested tumors, which were sensitive to the action of 2,3-dihydroxybutyraldehyde, were virtually devoid of aldehyde dehydrogenase activity. These results suggest a possible relationship between the lack of this enzyme activity and the antitumor activity of aliphatic aldehydes.

Aldehyde Oxidoreductases↗