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K D Courtney

Publications and source records attributed to K D Courtney.

35 records · Page 2Linked to original sources
PubMed1981

2,4,5-T effects on cardiac and serum lactic dehydrogenase (LDH) and creatine kinase (CK) isozymes. I. Maternal enzyme activities and isozyme profiles.

Pregnant mice were exposed to 100 mg/kg 2,4,5-T, IG, on gestation days 6 through 17, and sacrificed on postpartum day 1 or 21. Toxicologic evaluation showed no changes in body weight, heart weight, heart to body weight ratio, or cardiac supernate protein between corn oil control and 2,4,5-T treated mice on days 1 or 21 postpartum (pp). There were no effects of 2,4,5-T treatment on the total LDH enzyme activity of cardiac supernate on day 1 or 21pp. Serum LDH total activity was depressed on day 1pp and comparable to control values on day 21pp. Cardiac CK total activity was elevated on day 1pp, but not on day 21pp. Serum CK total activity on day 1 was comparable to control values; however, on day 21, a significant decrease in activity was observed. Cardiac LDH and CK isozyme profiles were normal on days 1 and 21pp. The serum LDH isozyme profile was normal at both times. The serum CK isozyme profile on Day 1 was markedly altered by athe appearance of two aberrant isozyme bands while on day 21, there was a profile shift with an increase in the BB band and a compensatory decrease in the MM band. These changes in creatine kinase suggest metabolic or pathologic changes in the cardiac muscle.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1981

2,4,5-T effects on cardiac and serum lactic dehydrogenase (LDH) and creatine kinase (CK) isozymes. II. Neonatal enzyme activities and isozyme profiles.

Neonates from CD-1 mice, which were treated during gestation with 100 mg/kg of 2,4,5-T, were studied from day 1 to 30 postpartum (pp) for effects on cardiac development by determining total cardiac activities and isozyme profiles of LDH and CK. On day 1pp, the total activities and isozyme profiles of LDH of the neonatal hearts were normal. During the developmental period of day 7 through 15, changes were noted in the developmental pattern of LDH isozymes some of which continued to day 30. The CK isozyme profile on day 1pp showed a significant change and changes continued throughout the lactational period. During this period, the normal developmental isozyme patterns of LDH and CK were altered by prenatal exposure to 2,4,5-T suggesting metabolic derangement or pathological changes in the neonatal heart.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1978

Isozyme profiles of lactic dehydrogenase and creatine phosphokinase in neonatal mouse hearts.

Isozyme profiles of lactic dehydrogenase (LDH) and creatine phosphokinase (CPK) were determined in cardiac tissue of mice during postnatal development. LDH isozymes 1 and 5 showed a definite developmental change, achieving the adult values by 20 days of age, while the other three isozymes showed no change. During the first 2 postnatal weeks, a developmental change was seen in the activities of the 'mito' and MB isozymes of CPK, with the adult profile being established by day 20. CPK isozymes MM and BB did not change during this interval.

Age Factors↗
PubMed1977

Prenatal effects of herbicides: evaluation by the prenatal development index.

The herbicides 2,4-D and 2,4,5-T and many of the esters of these compounds produced cleft palates in CD-1 mice. Silvex and Agent Orange also produced cleft palates. Depending on the dose and means of administration variable responses relating to the production of cleft palates, effect on fetal weight, and effect on fetal mortality were obtained. In order to view these data comprehensively, the Prenatal Development Index was determined. This index was computed from the incidence of malformed fetuses, fetal mortality and fetal body weight. This made it possible to evaluate data from some experiments with feto-toxic doses of compounds in which the high incidence of fetal mortality and consequently low incidence of viable fetuses obscured the response.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1970

Teratogenic evaluation of 2,4,5-T.

The herbicide 2,4,5-trichlorophenoxyacetic acid is teratogenic and fetocidal in two strains of mice when administered either subcutaneously or orally and in one strain of rats when administered orally. The incidences of both cystic kidney and cleft palate were increased in the C57BL/6 mice as well as the incidence of cleft palate in the AKR mice. The incidence of cystic kidney was also increased in the rats. In addition, an increase in the ratio of liver weight to body weight in the mouse fetus and the occurrence of hemorrhagic gastrointestinal tract in the rat fetus suggest that this compound also has fetotoxic properties.

Abnormalities, Drug-Induced↗