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Biomedical subjects

J Frendo

Publications and source records attributed to J Frendo.

At least 19 recordsLinked to original sources
PubMed1993

Seasonal variation in the activity of 3-mercaptopyruvate sulphurtransferase of the frog (Rana temporaria) liver.

1. Annual changes in the mitochondrial and cytosolic activity of MPST, GDH as a mitochondrial marker, and total protein content, were studied in frog (Rana temporaria) liver cells. 2. The variation in the MPST activity in mitochondria, regardless of the sex of the studied animals, is evidently under the influence of the thyroid gland activity, oxygen consumption and ambient temperature. 3. In the cytosol of the frog liver cells, seasonal changes of MPST specific activity seemed to be related to the production of mitochondrial iron-sulphur protein and to the protein-dependent metabolism during the fasting period.

Animals↗
PubMed1992

Seasonal changes in the activity of rhodanese in frog (Rana temporaria) liver.

1. The investigators studied annual changes in rhodanese activity in mitochondria and cytosol of frog liver cells (Rana temporaria) and found that the value of the enzyme-specific activity was higher in mitochondria than in cytosol, showing significant seasonal fluctuations. 2. The character of changes in the rhodanese activity in mitochondria, regardless of the sex of the studied animal, was demonstrated to be dependent upon the seasonal changes in frog thyroid gland function. 3. In the supernatant fraction of R. temporaria liver homogenate, seasonal changes of rhodanese specific activity seemed to be related to changes in hepatic function.

Acclimatization↗
PubMed1992

The effect of cAMP and some sulphur compounds upon the activity of mercaptopyruvate sulphurtransferase and rhodanese in mouse liver.

The aim of the experiments was to evaluate the effect of administration of cysteine, methionine, thiocystine, and thiosulphate upon the activity of mercaptopyruvate sulphurtransferase (MPST) and rhodanese in mouse liver. It was found that rhodanese activity increased following thiocystine and methionine administration and showed a smaller increase after cysteine and thiosulphate. The MPST activity significantly increased after cysteine and to a lesser extent after thiocystine and thiosulphate. On the other hand, methionine seemed to exert no effect upon the enzymatic activity. The results suggested that methionine metabolic cycle in mouse liver proceeded from cysteine to sulphane sulphur as thiocystine and, therefore, these three compounds increased rhodanese activity. Thiosulphate seemed rather to be involved in metabolic changes related to maintaining the stability of the physiological thiosulphate level and activated both the enzymes.

Animals↗
PubMed1986

Coronary circulation and myocardial metabolism in dilated cardiomyopathy.

Chest pain is a frequent complaint in patients with dilated cardiomyopathy (DCMP). Myocardial blood flow, coronary circulation parameters and coronary sinus lactate content were measured in 14 patients with DCMP and 10 healthy subjects. Myocardial blood flow in DCMP was 53.1 +/- 3.3 vs. 66.3 +/- 4.9 ml/min/100 g in the control group (p less than 0.05), coronary driving pressure was 59.1 +/- 4.6 vs. 72.8 +/- 8.8 mmHg (p less than 0.01). Subendocardial flow index (DPTI/TTI) in DCMP was 0.76 +/- 0.12 vs. 1.15 +/- 0.19 (p less than 0.01). The lactate content in coronary sinus blood was greater (1.93 +/- 0.45 mmol/l) than in the control group (1.43 +/- 0.48) (p less than 0.05). These results suggest that in DCMP myocardial blood flow is decreased, and in the majority of patients lactate is produced. Thus, it is possible that pain in DCMP is of anginal origin.

Adolescent↗