Characterization of particulate cyclic nucleotide phosphodiesterases of rat kidney

Inwegen, R. G. Van; Swafford, Richard L.; Strada, Samuel J.; Thompson, W. J.

doi:10.1016/0003-9861(77)90171-0

Cited by 21 publications

(5 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…supernatant of dog kidney by preparative DEAE-cellulose chromatography. Kidney tissue was chosen because it has a relatively high specific activity compared to other tissues and because it has a relatively high percentage of soluble vs. particulate high-affinity enzyme activity (Van Inwegen et al, 1977). Approximately 75% of the activity measured with 0.25 ^M cAMP as substrate was recovered in the 100000?…”

Section: Resultsmentioning

confidence: 99%

Purification and characterization of high-affinity cyclic adenosine monophosphate phosphodiesterase from dog kidney

Thompson¹,

Epstein²,

Strada³

1979

Biochemistry

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Purification and characterization of high-affinity cyclic adenosine monophosphate phosphodiesterase from dog kidney

Thompson¹,

Epstein²,

Strada³

1979

Biochemistry

View full text Add to dashboard Cite

“…Ca++ in low concentrations, is necessary for action of endogenous protein activators of phosphodiesterases (29,207). VanInwegen et al (202) has also shown recently that Ca++ markedly enhances th;-activation of cyclic AMP hydrolysis by cyclic GMP with high affinity, kidney membrane cyclic AMP phosphodiesterase. Prolonged high levels of cyclic AMP have been shown in vitro to increase phosphodiesterase activity (50,121).…”

Section: Degradation Of Cyclic Nucleotidesmentioning

confidence: 93%

“…The activities of these phosphodiesterases can be modulated by a number of factors (5,27,187,199,202,213,214). Mg++ and Mn++ will produce optimal activity of these enzymes in fresh preparations; in stored preparations, Mg++ is more effective.…”

Section: Degradation Of Cyclic Nucleotidesmentioning

confidence: 98%

See 1 more Smart Citation

Regulation of Cyclic AMP and Cyclic GMP in Morris Hepatomas and Liver

Hickie

1978

Morris Hepatomas

View full text Add to dashboard Cite

SUMMARYStudies on the regulation of tissue levels and action of adenosine 3':5'-monophosphate (cyclic AMP) and cyclic guanosine 3':5'-monophosphate (cyclic GMP) in Morris hepatomas and liver have been reviewed. Though the data is incomplete in some areas, the following generalizations can be made. A prominent difference between Morris hepatomas and normal liver, in relation to cyclic AMP formation, is the decreased responsiveness of tumor adenylyl cyclase to glucagon. This characteristic is most marked in rapidly growing hepatomas and appears to be associated with diminished plasma membrane binding of glucagon; regenerating liver and fetal liver resemble hepatomas in their responsiveness to glucagon. The responsiveness of adenylyl cyclase to epinephrine is, in contrast, generally enhanced in hepatomas as well as in regenerating and fetal liver. Marked increases in particulate guanylyl cyclase activities, relative to corresponding soluble activities, are seen consistently in Morris hepatomas and in regenerating and fetal liver; in the latter tissues, increases in plasma membrane guanylyl cyclase activities can be correlated with increased proliferative activity. Although the total cyclic AMP phosphodiesterase activities are significantly reduced in all Morris hepatomas examined, the activities of the high affinity (low Km) cyclic AMP phosphodiesterase in plasma membranes from some Morris hepatomas are higher than those of normal liver. The degradation of cyclic GMP by Morris hepatomas is also impaired, most notably in the particulate fractions. In regenerating and fetal liver the activities of cyclic AMP and cyclic GMP phosphodiesterases are, in contrast, not changed appreciably. The ratios of cyclic GMP levels, relative to cyclic AMP, tend to be higher in Morris hepatomas than in normal liver. Though these ratios are highest in rapidly growing hepatomas, the correlation between cyclic nucleotide levels and tumor growth rate is not strong. The correlation between cyclic GMP/cyclic AMP ratios and hepatocyte proliferation is controversial at this time; the most recent studies on regenerating liver suggest that these ratios are increased prior to the proliferative phase. Only a few studies have been carried out on cyclic nucleotide binding proteins and kinases. These studies indicate that: cytosols from rapidly growing hepatomas have a reduced ability to bind cyclic AMP with increased (?) binding of cyclic GMP; there is a positive correlation between cyclic AMP binding and tumor sensitivity to growth inhibition by dibutyryl cyclic AMP; cytosol fractions from rapidly growing hepatomas generally have reduced cyclic AMP dependent protein kinase activities and increased endogenous (cyclic AMP independent) kinase activities.

show abstract

“…However, when the chelator was added to the incubation medium together with cGMP, the stimula- Brush border membranes were prepared by two different procedures, as described in Materials and Methods, and these are designated Method I and II. Previously, cGMP was found to stimulate cAMP hydrolysis by particulate fractions from several different tissues [8] and EGTA was found to enhance the cGMP-stimulated hydrolysis by cytosolic phosphodiesterases [36,17]. Values are means • of four (brush border) or eight (basal-lateral membranes) determinations.…”

Section: Cyclic Nucleotide Activation and Inhibitionmentioning

confidence: 99%

Cyclic nucleotide phosphodiesterases of the renal cortex

Sacktor

1977

J. Membrain Biol.

View full text Add to dashboard Cite

Characterization of particulate cyclic nucleotide phosphodiesterases of rat kidney

Cited by 21 publications

References 30 publications

Purification and characterization of high-affinity cyclic adenosine monophosphate phosphodiesterase from dog kidney

Purification and characterization of high-affinity cyclic adenosine monophosphate phosphodiesterase from dog kidney

Regulation of Cyclic AMP and Cyclic GMP in Morris Hepatomas and Liver

Cyclic nucleotide phosphodiesterases of the renal cortex

Contact Info

Product

Resources

About