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Biomedical subjects

T Aoyagi

Publications and source records attributed to T Aoyagi.

At least 325 records · Page 18Linked to original sources
PubMed1985

Bestatin, a microbial aminopeptidase inhibitor, inhibits DNA synthesis induced by insulin or epidermal growth factor in primary cultured rat hepatocytes.

Bestatin, a microbial aminopeptidase inhibitor, inhibited insulin- or epidermal growth factor-induced DNA synthesis and cell proliferation in primary cultured hepatocytes of rats. The aminopeptidase inhibitor also affected the growth of FM3A or LOBN cells of mice, when it is included in the culture media at the concentration of 0.5 mg/ml. These results suggest the important role of the bestatin-sensitive aminopeptidase(s) in the process of DNA synthesis and proliferation of animal cells.

Aminopeptidases↗
PubMed1985

Relation of blood glucose levels to the changes in plasma levels of various hydrolytic enzymes in diabetic patients.

Plasma levels of various hydrolytic enzymes in diabetic patients, as diagnosed by their blood glucose levels, were compared with those of control subjects. Most of the levels of the aminopeptidase activities examined were significantly increased, while those of angiotensin-converting enzyme (ACE) and esterase decreased, in diabetic patients. The results of multivariate analysis suggest that the increased aminopeptidase activities are related rather to secondary organ lesions than to the primary pancreatic lesion. It seems that the blood glucose level is not necessarily a good indicator of metabolic abnormalities underlying this pathological condition.

Acetylcholinesterase↗
PubMed1985

Influence of angiotensin-converting enzyme inhibitor, foroxymithine, on dynamic equilibrium around the renin-angiotensin system in vivo.

To understand the in vivo actions of angiotensin-converting enzyme (ACE) inhibitors, a prolonged study was performed in rabbits over a half year, using one of such inhibitors, foroxymithine. During the initial 2 months of the inhibitor administration, the serum level of ACE was suppressed. Thereafter, probably triggered by the consequent sharp rise in the plasma renin activity (PRA) level, the ACE level regained its initial value. Thus the close correlation between the levels of PRA and ACE seen in the control animal was entirely broken by this inhibitor. A multivariate study indicated that the inhibitor drastically changed the normal networks of peptide metabolism in vivo. These results are compatible with the notion that the ACE inhibitor blocks the regulatory mechanisms of the renin-angiotensin system in vivo.

Angiotensin I↗
PubMed1985

Systemic changes in hydrolytic enzyme activities in mice affected with murine leprosy.

In order to investigate the behavior of hydrolytic enzymes in chronic infections, the activities of 17 hydrolytic enzymes were tested in limb muscles, heart muscle, spleen, liver, and kidney of lepromatous mice infected with Mycobacterium lepraemurium (M. lepraemurium) and their controls. Typical increases in those enzymatic activities were seen in spleen and liver, where pathological changes were the most pronounced, especially at the 11th week after the inoculation of the bacilli. At the 16th week, the enzymatic changes became less remarkable probably because of the decreased viability of tissues in these organs. The enzymatic changes observed could not be explained as due to bacterial enzymes. These findings are compatible with the notion that the increases in hydrolytic enzyme activities are related to tissue damage caused by murine leprosy.

Animals↗
PubMed1985

Effect of esterastin, an acid lipase inhibitor, on the free and esterified cholesterol contents of cultured aortic smooth muscle cells treated with LDL and cholesterol ester liquid crystals.

The effects of esterastin, an acid lipase inhibitor, on the free and esterified cholesterol contents of cultured smooth muscle cells from pig aorta were examined. The post-nuclear supernatant fraction of the cell homogenate showed maximum acid cholesterol esterase activity at pH 4.5, and 50% of this activity was inhibited by 0.31 microM esterastin. During a 48 h incubation with esterastin, the esterified cholesterol content of the cells increased to about 13 times that of control cells in the presence of low density lipoprotein and to 7 times that of control cells in the presence of cholesterol oleate liquid crystals. The ratio of esterified to free cholesterol also increased to about 5 times the control value in both conditions.

Animals↗
PubMed1985

Dissociation of creatine kinase activity from hydrolytic enzyme activities in muscle of dystrophic mice.

Time course studies were done to reexamine the age-dependency of intramuscular enzymatic changes in dystrophic mice. Most of the activities of hydrolytic enzymes in dystrophic mice were elevated in comparison to the controls throughout the span of 8 weeks which was examined. In contrast, the activity of creatine kinase remained depressed throughout the same period. This tendency was similarly seen in the muscles of forelimb and hindlimb but not in heart muscle. The observations are compatible with the notion that the increased activities of hydrolytic enzymes are causally related to the destruction of muscular tissue, leading to the malfunction of contractile machinery in the dystrophic muscles.

Animals↗
PubMed1984

Electrophoretic study of keratin polypeptides in chemically-induced oral carcinomas in the hamster.

Comparison was made of the electrophoretic keratin polypeptide patterns of normal hard palate epithelia from three hamsters and of eight palatal squamous cell carcinomas induced by 7,12-dimethylbenz(a)anthracene (DMBA) treatment. Keratin polypeptides from normal epithelia had a molecular weight range of about 48,000 to 70,000. In the tumour extracts, the large polypeptides (above 61,000) found in the normal epithelia were absent, but the majority of other small polypeptides below 61,000 were expressed. Three as yet undefined polypeptides, in the range of 40,000 to 70,000, were detected in tumour extracts, but not in extracts of normal palatal mucosa. The keratin polypeptide electrophoretic alterations in carcinomas of hamster palatal mucosa are similar to those reported for extra-oral carcinomas in other animal species.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1984

Role of intramuscular enzymatic changes in the development of muscular weakness in rats with experimental allergic neuritis.

We investigated the role of intramuscular enzymatic changes in the development of muscular weakness in rats suffering from experimental allergic neuritis. At an initial stage without apparent clinical symptoms, enzymatic changes of similar types occurred in the muscles of the forelimbs and hind limbs. At a later stage when the weakness appeared in the hind limb but not in the forelimb, dissociation of the pattern of the enzymatic changes occurred between the two limbs. Comparison of the intramuscular enzymatic changes between the two stages and between the two limbs suggested that the increased activities of aminopeptidases and endopeptidases play some important roles in the development of muscular weakness in this experimental model. Low molecular weight protease inhibitors may thus be worthy of a trial in this disease condition.

Aging↗