THE EFFECT OF AGE, SEX, AND PREVIOUS PREGNANCY ON OXYGEN UPTAKE OF MAMMARY TISSUE OF MICE OF THE C57BL, A, AND C3H STRAINS

1953 ◽  
Vol 31 (5) ◽  
pp. 400-405
Author(s):  
Jules Tuba ◽  
Herbert E. Rawlinson ◽  
Lorna G. Shaw ◽  
M. Shirley Fraser ◽  
Irmgaard Jeske
Keyword(s):  
Enzyme Activity ◽  
Oxygen Uptake ◽  
Tumor Tissue ◽  
Significant Rise ◽  
Mammary Tissue ◽  
Previous Pregnancy ◽  
Enzyme Systems ◽  
Effect Of Age ◽  
Mammary Tumor Tissue ◽  
Usual Pattern

Oxygen uptake of mammary tissue of mice of the C57BL, A, and C3H strains has been studied in the presence [Formula: see text] and in the absence of p-phenylenediamine (Qo2). In general, these values are affected significantly by the age, sex, breeding history, and strain of the animals. The effect of these factors on enzyme activity has been observed with a number of enzyme systems and once more emphasizes their importance in evaluating data obtained in animal enzyme studies. A notable departure from the usual pattern for the Qo2 values was observed with mice of the C3H strain. There was a significant rise in the Qo2 values and a diminution in the cytochrome reserves [Formula: see text] for breeder females about the time spontaneous mammary tumors begin to appear. A similar elevation in Qo2, and diminution in reserves of the cytochrome system, appeared in mammary tumor tissue obtained from C3H females. The situation for virgin females is much the same with regard to the Qo2 and [Formula: see text] values of mammary tissue. The males of this strain manifest an abnormal elevation in Qo2 values but there is no diminution in [Formula: see text] levels.

THE EFFECT OF AGE, SEX, AND PREVIOUS PREGNANCY ON THE OXYGEN UPTAKE OF RAT MAMMARY TISSUE

1952 ◽  
Vol 30 (1) ◽  
pp. 14-17
Author(s):  
Jules Tuba ◽  
M. Shirley Fraser
Keyword(s):  
Oxygen Consumption ◽  
Breast Tissue ◽  
Female Rats ◽  
Mammary Tissue ◽  
Previous Pregnancy ◽  
Consumption Values ◽  
Group 12 ◽  
History Of ◽  
Normal Rat ◽  
Effect Of Age

The effect of age, sex, and breeding on oxygen consumption and response to p-phenylenediamine of normal rat mammary tissue has been studied. Oxygen consumption values [Formula: see text] are significantly higher for breeder females than for virgin females or males. The endogenous oxygen consumption by breast tissue of virgin rats more closely resembles that of males than of breeder females. There is a significant lowering of [Formula: see text] with age in all the animals. Oxygen consumption in the presence of p-phenylenediamine [Formula: see text] is not significantly different for mammary tissue of males and breeders of the youngest age group (12–25 weeks) but it is higher for virgins of the same age. A highly significant fall in [Formula: see text] to approximately equal levels appears at a comparatively early age (30–50 weeks) in males and virgins, but this does not occur in the breeder female rats until the ability to reproduce has diminished or ceased (50 weeks and over). Reserves of the cytochrome system [Formula: see text] are lower in breeders than in males or virgins and are decreased by age in the latter two groups. These studies indicate the importance of considering age, sex, and breeding history of animals used for mammary tissue respiratory studies.

Preparation of enzymatically highly active pegylated-D-amino acid oxidase and its application to antitumor therapy

2021 ◽  
Vol 18 ◽  
Author(s):  
Hideaki Nakamura ◽  
Appiah Enoch ◽  
Shotaro Iwaya ◽  
Sakura Furusho ◽  
Shoko Tsunoda ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Antitumor Effect ◽  
Tumor Tissue ◽  
Acid Oxidase ◽  
Antitumor Therapy ◽  
Amino Acid Oxidase ◽  
Tumor Bearing ◽  
Highly Active ◽  
High Enzyme ◽  
High Enzyme Activity

Background: D-amino acid oxidase (DAO) is an H2O2-generating enzyme, and tumor growth suppression by selective delivery of porcine DAO in tumors via the cytotoxic action of H2O2 has been reported. DAO isolated from Fusarium spp. (fDAO) shows much higher enzyme activity than porcine DAO, although the application of fDAO for antitumor treatment has not yet been determined. Objective: The purpose of this study was to prepare enzymatically highly active pegylated-fDAO, and to determine whether it accumulates in tumors and exerts a potent antitumor effect in tumor-bearing mice. Methods: Polyethylene glycol (PEG; Mw. 2000) was conjugated to fDAO to form PEGylated fDAO (PEG-fDAO). PEGfDAO was intravenously administered into S180 tumor-bearing mice, and the body distribution and antitumor activity of PEG-fDAO was determined. Results: The enzyme activity of PEG-fDAO was 26.1 U/mg, which was comparable to that of fDAO. Intravenously administered PEG-fDAO accumulated in tumors with less distribution in normal tissue except in the plasma. Enzyme activity in the tumor was 60–120 mU/g-tissue over 7–20 h after i.v. injection of 0.1 mg of PEG-fDAO. To generate the H2O2 in the tumor tissue, PEG-fDAO was intravenously administered, and then, D-phenylalanine was intraperitoneally administered after a lag time. No remarkable tumor suppression effect was observed under conditions used in this study, compared to the non-treated group. Conclusion: The results suggest that PEG-fDAO maintained high enzymatic activity after pegylation. Treatment with PEGfDAO conferred high enzyme activity on tumor tissue; 3–6 fold higher than that of previously reported pDAO; however, high enzyme activity in the plasma limited repeated treatment owing to lethal toxicity, which seemingly led to poor therapeutic outcome. Overall, the use of PEG-fDAO is promising for antitumor therapy, although the suppression of DAO activity in the plasma would also be required rather than only the increase in DAO activity in the tumor for an antitumor effect.

Effect of Age and Postoperative Time on Cytochrome P450 Enzyme Activity Following Liver Transplantation

2005 ◽  
Vol 45 (6) ◽  
pp. 666-673 ◽  
Author(s):  
Shanshan Liu ◽  
Reginald F. Frye ◽  
Robert A. Branch ◽  
Raman Venkataramanan ◽  
John J. Fung ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Enzyme Activity ◽  
Cytochrome P450 ◽  
Cytochrome P450 Enzyme ◽  
P450 Enzyme ◽  
Postoperative Time ◽  
Effect Of Age

Antioxidant enzymes of the human retina: effect of age on enzyme activity of macula and periphery

1996 ◽  
Vol 15 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Monica A. De La Paz ◽  
Jian Zhang ◽  
Irwin Fridovich
Keyword(s):  
Enzyme Activity ◽  
Antioxidant Enzymes ◽  
Human Retina ◽  
Effect Of Age

Studies of the enzyme activity of Bact. lactis aerogenes (Aerobacter aerogenes) - I. The effects of cellular disruption on the activities of some typical enzymes

1964 ◽  
Vol 160 (978) ◽  
pp. 25-41 ◽  
Keyword(s):  
Enzyme Activity ◽  
Cell Surface ◽  
Normal Activity ◽  
Ultrasonic Vibrations ◽  
Aerobacter Aerogenes ◽  
Enzyme Systems ◽  
Actual Location

When cells of Bact. lactis aerogenes (Aerobacter aerogenes) are disrupted by exposure for various times ( a ) to benzene, or ( b ) to ultrasonic vibrations the activity of some representative enzyme systems changes according to one of two patterns. In pattern I it rises to a maximum from which it then declines; in pattern II it falls from the start, the rate of fall varying from enzyme to enzyme. β -galactosidase and asparagine deaminase show pattern I and catalase pattern II, whichever method of disruption is used. Non-induced dehydrogenases in ( b ) show pattern I while fully mobilized dehydrogenases show pattern II. All are very rapidly inactivated in ( a ). Discussion of the results suggests that the susceptibility of the enzyme to damage may be a function of its complexity, and that the pattern of inactivation depends upon how far the normal activity is limited by rate of access, this in turn depending partly upon the actual location of the enzyme, which in some cases is in or near the cell surface.

THE INFLUENCE OF ADRENALECTOMY UPON THE ACTIVITY OF THE HEXOSEMONOPHOSPHATE SHUNT IN THE LIVERS AND MAMMARY GLANDS OF LACTATING RATS

1960 ◽  
Vol 38 (1) ◽  
pp. 1265-1273 ◽  
Author(s):  
J. S. Willmer
Keyword(s):  
Enzyme Activity ◽  
Considerable Increase ◽  
Mammary Glands ◽  
Mammary Tissue ◽  
Hepatic Tissue ◽  
Phosphogluconate Dehydrogenase ◽  
Growth Changes ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Adrenalectomized Rats ◽  
Hepatic Level

The development of the hexosemonophosphate shunt in mammary tissue and liver of lactating rats has been studied. A sixfold increase in mammary glucose-6-phosphate dehydrogenase levels between parturition and weaning was accompanied by a considerable increase in 6-phosphogluconate dehydrogenase activity. The hepatic level of the former enzyme was also elevated 11-fold during this period. Adrenalectomy at parturition, or on the 3rd, 6th, 9th, or 14th days of lactation, depressed the activity of this pathway in mammary gland, a lowered level being observed in all cases after operation. A slight increase in enzyme activity was found in hepatic tissue in the immediate postoperative period; this was succeeded by a decrease.These results are discussed in relation to the growth changes observed in groups of unoperated and adrenalectomized rats.

EFFECT OF AGE AND SEX ON OXYGEN UPTAKE BY ADULT MOSQUITOES

1962 ◽  
Vol 5 (4) ◽  
pp. 244-248 ◽  
Author(s):  
MARIASSA BAT-MIRIAM ◽  
RACHEL GALUN
Keyword(s):  
Oxygen Uptake ◽  
Effect Of Age ◽  
Age And Sex
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