1
|
|
2
|
Giembycz MA, Barnes PJ. Selective inhibition of a high affinity type IV cyclic AMP phosphodiesterase in bovine trachealis by AH 21-132. Relevance to the spasmolytic and anti-spasmogenic actions of AH 21-132 in the intact tissue. Biochem Pharmacol 1991; 42:663-77. [PMID: 1650218 DOI: 10.1016/0006-2952(91)90330-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The ability of a papaverine-derived bronchodilator, AH 21-132, to inhibit cyclic nucleotide hydrolysis and to increase the cAMP content and the activity of cAMP-dependent protein kinase (A-kinase) was evaluated in bovine tracheal smooth muscle (BTSM) and related to the mechanical effects elicited by this compound in vitro. AH 21-132 (100 nM-1 mM) produced a concentration-related relaxation of BTSM pre-contracted with methacholine (MCh) that was subject to marked functional antagonism. AH 21-132 (100 microM) also displayed anti-spasmogenic activity preventing the generation of tone induced by low, but not high, concentrations of MCh. Neither the spasmolytic nor anti-spasmogenic effects of AH 21-132 were antagonized by the beta 2-adrenoceptor blocking drug ICI 118551 (50 nM). Three Ca(2+)- and calmodulin-independent cyclic nucleotide phosphodiesterases (PDE) were resolved from the soluble fraction of BTSM homogenates by Q-Sepharose anion exchange chromatography. These PDEs were identified by kinetic and inhibitor sensitivity criteria as the Type II (cGMP-stimulated), Type IV (Ro 20-1724-inhibited) and Type V (cGMP-specific) isoenzymes. A small amount (approximately 5%) of a Type III PDE seemed to be present but this was not identified with certainty. AH 21-132 selectively inhibited Type IV PDE in a competitive manner with an IC50 and KI of 3.7 and 2.7 microM, respectively. AH 21-132 similarly increased the cAMP content (from 5.3 to 23.1 pmol/mg protein after 1 mM AH 21-132) and activated A-kinase (from 29.6% to 53.5% after 1 mM AH 21-132) in intact BTSM over the same concentration range at which this compound influenced tone. In addition, AH 21-132 in high concentrations (greater than 100 microM), while exerting no direct effect on A-kinase itself, markedly potentiated (ca. four-fold at 3 mM AH 21-132) the ability of cAMP to activate A-kinase without affecting the affinity of cAMP for this enzyme. It is concluded that the spasmolytic and anti-spasmogenic effects of AH 21-132 in BTSM may be related, in part, to its ability to inhibit Type IV PDE, increase the intracellular cAMP content and so activate A-kinase. A cyclic nucleotide-dependent mechanism is therefore proposed. In addition, the ability of AH 21-132 to augment cAMP-dependent phosphorylation in a cell-free system, when Type IV PDE is inhibited fully, provides the possibility that the observed relaxation elicited by high concentrations of AH 21-132, while cAMP-dependent, does not require any further increase in the intracellular cAMP concentration.
Collapse
Affiliation(s)
- M A Giembycz
- Department of Thoracic Medicine, National Heart and Lung Institute, Royal Brompton Hospital, London, U.K
| | | |
Collapse
|
3
|
von der Leyen H. Phosphodiesterase inhibition by new cardiotonic agents: mechanism of action and possible clinical relevance in the therapy of congestive heart failure. KLINISCHE WOCHENSCHRIFT 1989; 67:605-15. [PMID: 2671473 DOI: 10.1007/bf01718141] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cyclic AMP is known as a secondary messenger regulating the myocardial force of contraction. For the degradation of cAMP multiple forms of PDE within the cell are described, which vary according to substrate specificity, kinetic characterization, and cellular localization. One of these isoenzymes, the low Km cAMP-specific PDE (PDE III), which seems to be closely related to cardiotonic effects of PDE inhibitors, exists either in a particulate form (in dogs), probably associated with the sarcoplasmic reticulum, or in soluble form (in guinea pig). The existence of different forms of PDE III possibly reflects a different pooling or compartmentalization of cAMP. Many agents selectively inhibiting PDE III are described which potently increase the force of contraction and which exert vasodilatory effects. Besides PDE inhibition some of these agents possess additional cAMP-independent actions, e.g., sensitization of the contractile proteins to Ca2+, prolongation of the action potential, or prolongation of the open state of the Na+-channel. Since agents which nonselectively inhibit PDE are known as potent positive inotropic agents (e.g., IBMX), PDE III inhibition itself, but not a selectivity for PDE III inhibition, seems to be a prerequisite for this mechanism of action of cardiotonic drugs. Investigations with preparations from diseased human myocardium show that the beta-adrenoceptor agonist isoprenaline as well as the PDE inhibitor IBMX increase the force of contraction to only about one-third of the maximal effect of the cardiac glycoside dihydro-ouabain or Ca2+. In nonfailing human heart preparations all agents had equal activity. Possible reasons for these differences may be a decreased responsiveness to beta-adrenoceptor stimulation (beta-receptor down-regulation) or an inappropriate increase in cAMP levels due to increased activity of inhibitory Gi-proteins with resulting decrease of adenylate cyclase activity in the failing heart. Besides a short-term clinical and hemodynamic improvement of congestive heart failure, uncontrolled long-term administration of PDE III-inhibitor agents failed to produce sustained clinical benefit and had no effect on survival. Controlled long-term studies with new cardiotonic agents in patients with severe CHF are still lacking.
Collapse
Affiliation(s)
- H von der Leyen
- Abteilung Allgemeine Pharmakologie, Universitäts-Krankenhaus Eppendorf, Hamburg
| |
Collapse
|
4
|
Vale MR, Baker RV, Hope DB. Phosphodiesterase activities for cyclic nucleotides in nerve endings from the bovine posterior pituitary gland. J Neurochem 1984; 42:377-83. [PMID: 6319599 DOI: 10.1111/j.1471-4159.1984.tb02688.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The cyclic nucleotide phosphodiesterase (PDE) activities were studied in a nerve ending fraction from bovine neural lobes. Most of the activity was particulate and unaffected by calcium. Lineweaver-Burk plots for this fraction showed negative cooperativity with apparent Km values for cyclic AMP of 11 microM and for cyclic GMP of 4 microM. The soluble activities for both cyclic nucleotides were activated by calcium and inhibited by calmodulin-binding drugs (trifluoperazine and calmidazolium). The apparent Km values were 50 microM for cyclic AMP and 20 microM for cyclic GMP for the soluble activities. Sucrose density gradients resolved the soluble activities into two peaks. The activity with the higher sedimentation rate (MW 122,000 daltons) hydrolysed both cyclic nucleotides and was calcium-calmodulin-dependent. The other peak (MW 47,000 daltons) had a higher affinity for cyclic AMP than for cyclic GMP and was calcium-independent. Solubilized particulate activities gave two main peaks on the density gradient, both calcium-independent. One was mainly for cyclic AMP (MW 47,000 daltons) and the other mainly for cyclic GMP (MW 133,000 daltons). The function of PDEs in relation to secretion was discussed.
Collapse
|
5
|
Abstract
The cellular concentration of cyclic nucleotides is largely dependent upon the activity of the enzymatic system responsible for their degradation: cyclic nucleotide phosphodiesterase. This enzymatic system thus plays a crucial role in the regulation of the multiple functions which are modulated by cyclic nucleotides in the organism. Many methodological problems, as well as the complexity of the phosphodiesterase system have long maintained a confusion in this field. Recent progresses (purification to homogeneity of some enzymatic forms, discovery of regulatory mechanisms, particularly) have brought a considerable evolution in the knowledge of the system. It is now well established that cyclic nucleotide phosphodiesterase exists under several isoenzymatic forms, the properties and distribution of which largely differ from a tissue to another. Some of these forms are relatively well characterized, while the representativity of others is still discussed. The significance of this multiplicity of isoenzymes, and their interrelationships are presently under study. A very interesting aspect in the study of this enzymatic system is that it is submitted to several physiological regulatory processes. Recent studies on this point suggest that phosphodiesterase might play a major role in the response of the organism to several hormones. These fundamental studies of phosphodiesterase system find a most interesting application in the pharmacological field. Indeed, numerous synthetic compounds which inhibit the enzyme present a strong pharmacological interest.
Collapse
|
6
|
Gopalakrishna R, Anderson WB. Calmodulin interacts with cyclic nucleotide phosphodiesterase and calcineurin by binding to a metal ion-independent hydrophobic region on these proteins. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32939-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
7
|
Sarada K, Epstein PM, Strada SJ, Thompson WJ. Analysis of cyclic nucleotide phosphodiesterase(s) by radioimmunoassay. Arch Biochem Biophys 1982; 215:183-98. [PMID: 6284039 DOI: 10.1016/0003-9861(82)90294-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
8
|
Moore JB, Schroedter DE. Purification and characterization of human lung calmodulin-independent cyclic AMP phosphodiesterase. Arch Biochem Biophys 1982; 213:276-87. [PMID: 6277253 DOI: 10.1016/0003-9861(82)90463-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
9
|
Némoz G, Prigent AF, Pageaux JF, Pacheco H. Isoelectric-focusing patterns of cyclic nucleotide phosphodiesterase from rat heart. Biochem J 1981; 199:113-9. [PMID: 6279093 PMCID: PMC1163340 DOI: 10.1042/bj1990113] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
1. Isoelectric focusing on a flat gel bed of the rat heart cytosolic fraction resolved cyclic nucleotide phosphodiesterase activity into several forms, characterized by their substrate specificity, kinetic constants and dependence towards Ca2+ and calmodulin. A peak of pI 4.9 displayed 20 times more affinity for cyclic GMP than for cyclic AMP and was markedly inhibited by EGTA. A less substrate-specific form, only slightly sensitive to EGTA inhibition, focused at pH 5.45. Several overlapping peaks detected between pH 5.55 and pH6 specifically hydrolysed cyclic AMP, with non-Michaelian kinetics; these peaks were insensitive to Ca2+ chelation. 2. Isoelectric focusing did not dissociate enzyme-calmodulin complexes, as none of the resulting peaks was activatable by calmodulin plus Ca2+. 3. Some new information on rat cardiac phosphodiesterase is obtained with this technique, which is convenient for routine analytical studies of phosphodiesterase, as well as for preparative purposes.
Collapse
|
10
|
Strada SJ, Epstein PM, Gardner EA, Thompson WJ, Stancel GM. Evidence for convertible forms of soluble uterine cyclic nucleotide phosphodiesterase. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 661:12-20. [PMID: 6271215 DOI: 10.1016/0005-2744(81)90077-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The cyclic nucleotide phosphodiesterase (3':5'-cyclic nucleotide 5'-nucleotidohydrolase, EC 3.1.4.17) systems of many tissues show multiple physical and kinetic forms. In contrast, the soluble rat uterine phosphodiesterase exists as a single enzyme form with non-linear Lineweaver-Burk kinetics for cyclic AMP (app. Km of approx. 3 and 20 microM) and linear kinetics for cyclic GMP (app. Km of approx. 3 microM) since the two hydrolytic activities are not separated by a variety of techniques. In uterine cytosolic fractions, cyclic AMP is a non-competitive inhibitor of cyclic GMP hydrolysis (Ki approx. 32 microM). Also, cyclic GMP is a non-competitive inhibitor of cyclic AMP hydrolysis (Ki approx 16 microM) at low cyclic GMP/cyclic AMP substrate ratios. However, cyclic GMP acts as a competitive inhibitor of cyclic AMP phosphodiesterase (Ki approx 34 microM) at high cyclic GMP/cyclic AMP substrate ratios. When a single hydrolytic form of uterine phosphodiesterase, separated initially by DEAE anion-exchange chromatography, is treated with trypsin (0.5 microgram/ml for 2 min) and rechromatographed on DEAE-Sephacel, two major forms of phosphodiesterase are revealed. One form elutes at 0.3 M NaOAc- and displays anomalous kinetics for cyclic AMP hydrolysis (app. Km of 2 and 20 microM) and linear kinetics for cyclic GMP (app. Km approx. 5 microM), kinetic profiles which are similar to those of the uterine cytosolic preparations. A second form of phosphodiesterase elutes at 0.6 M NaOAc- and displays a higher apparent affinity for cyclic AMP (app. Km approx. 1.5 mu) without appreciable cyclic GMP hydrolytic activity. These data provide kinetic and structural evidence that uterine phosphodiesterase contains distinct catalytic sites for cyclic AMP and cyclic GMP. Moreover, they provide further documentation that the multiple forms of cyclic nucleotide phosphodiesterase in mammalian tissues may be conversions from a single enzyme species.
Collapse
|
11
|
Yamanaka MK, Kelly LE. A calcium/calmodulin-dependent cyclic adenosine monophosphate phosphodiesterase from Drosophila heads. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 674:277-86. [PMID: 6263352 DOI: 10.1016/0304-4165(81)90385-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A Ca2+-activated cycl AMP phosphodiesterase from Drosophila melanogaster heads was studied. The enzyme accounted for approx. 40% of the total, soluble cyclic AMP phosphodiesterase activity in heads. After gel filtration, Ca2+ stimulation of the enzyme was no longer apparent, but Ca2+ activation could be restored by the addition of boiled Drosophila extract to the column-fractionated phosphodiesterase. The protein responsible for restoring Ca2+ activation was purified and shown to have some characteristics of calmodulin. In addition, porcine calmodulin was able to activate the Drosophila phosphodiesterase. Thus, the phosphodiesterase-calmodulin system in Drosophila appears analogous to similar systems in mammals.
Collapse
|
12
|
Byers D, Davis RL, Kiger JA. Defect in cyclic AMP phosphodiesterase due to the dunce mutation of learning in Drosophila melanogaster. Nature 1981; 289:79-81. [PMID: 6256649 DOI: 10.1038/289079a0] [Citation(s) in RCA: 306] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cyclic AMP is an intracellular mediator ('second messenger') in the nervous and endocrine control of cellular function, regulating different processes in different cell types. Although evidence is incomplete, it seems that cyclic AMP enhances the calcium-mediated release of neurotransmitter in some neurones. A simple form of memory in the mollusc Aplysia is probably encoded as a cyclic AMP-induced enhancement of neurotransmission at certain synapses of the central nervous system. The possibility that cyclic AMP participates in learning mechanisms may be explored using genetic mutants. For this purpose the fruitfly Drosophila is suitable as it is genetically well characterized and can learn through olfaction, vision or taste. We show here that independent searches for mutations of olfactory learning and of cyclic AMP metabolism, and for mutations causing female infertility have each led to the same gene--the dunce gene. Our evidence indicates that the normal dunce gene may specify a cyclic AMP phosphodiesterase.
Collapse
|
13
|
Davis RL, Kiger JA. A partial characterization of the cyclic nucleotide phosphodiesterases of Drosophila melanogaster. Arch Biochem Biophys 1980; 203:412-21. [PMID: 6250491 DOI: 10.1016/0003-9861(80)90194-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
14
|
Keravis TM, Wells JN, Hardman JG. Cyclic nucleotide phosphodiesterase activities from pig coronary arteries. Lack of interconvertibility of major forms. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 613:116-29. [PMID: 6246952 DOI: 10.1016/0005-2744(80)90198-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
DEAE-cellulose chromatography, with or without dithiothreitol and over a pH range of 6.0 to 8.5, resolved two phosphodiesterase activities (peaks I and II) from the soluble fraction of pig coronary arteries. The activity of peak I was increased by calmodulin (3-7-fold), whereas that of peak II was not. Chromatography of peak I on Biol-Gel A-0.5 m columns resolved two peaks of phosphodiesterase activity (peaks Ia and Ib). Peak Ia was eluted in the presence or absence of 0.1 M KCl and was relatively insensitive to calmodulin. Peak Ib was eluted only in the presence of KCl and was sensitive to calmodulin. The substrate specificity and kinetic behavior were the same for peaks I, Ia, and Ib. Repeated gel chromatography of either peak Ia or Ib, under appropriate conditions, yielded a mixture of peaks Ia and Ib. Peak Ia appears to be a reversible aggregate of peak Ib. Gel chromatography of peak II resolved only one phosphodiesterase activity, which was eluted without KCl, was highly specific for cyclic AMP, was not sensitive to calmodulin and migrated differently on the gel column than either peak Ia or Ib. Sucrose density gradient centrifugation of the soluble fraction from pig coronary arteries in the presence or absence of dithiothreitol resolved two peaks of phosphodiesterase activity (6.6 S and 3.6 S) which were similar to peaks I and II separated by DEAE-cellulose chromatography with regard to their substrate specificity and their sensitivity to calmodulin. Upon recentrifugation, each of the two peaks of phosphodiesterase activity gave a single peak of activity which migrated with the same S value as did its parent. These results indicate that the two major forms of phosphodiesterase of pig coronary arteries, which are representative of those found in many tissues, are not interconvertible in cell-free systems.
Collapse
|
15
|
Erneux C, Couchie D, Dumont JE. Characterization of horse thyroid cyclic nucleotide phosphodiesterases. EUROPEAN JOURNAL OF BIOCHEMISTRY 1980; 104:297-304. [PMID: 6245870 DOI: 10.1111/j.1432-1033.1980.tb04428.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
16
|
Kalderon AE, Dobbs JW, Greenberg ML. Localization of 3',5'-cyclic adenosine monophosphate phosphodiesterase (cAMP-PDEase) activity in isolated bovine thyroid plasma membranes. HISTOCHEMISTRY 1980; 65:277-89. [PMID: 6246042 DOI: 10.1007/bf00493177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Isolated bovine thyroid plasma membrane preparations were obtained by isopycnic density gradient centrifugation. Cyclic AMP-PDEase (EC 3.1.4.c) activity has been demonstrated by electron microscopic histochemistry on the unit membrane of isolated bovine thyroid cells. 3-isobutyl-1-methyl-xanthine (IBMX) produced partial inhibition, while omission of the substrate revealed no reaction product deposition. These observations correlated well with biochemical studies that showed 0.4% of the total cAMP-PDEase activity to be present in the plasma membrane preparations. Kinetic analysis of cAMP hydrolysis yielded two apparent Michaelis constants for the homogenate and the plasma membrane-rich fraction. Dose-response curves for IBMX inhbition showed cAMP-PDEase of the homogenate to be more sensitive to inhibition than that of the plasma membrane-bound enzyme. Furthermore, wash experiments indicate that the plasma membrane-associated enzyme is tightly bound. This investigation strengthens our previous study and suggests that bovine thyroid cell plasma membranes contain a cAMP-PDEase that may be involved in interactions between the cell and the external environment in a manner yet to be determined.
Collapse
|
17
|
Epstein PM, Pledger WJ, Gardner EA, Stancel GM, Thompson WJ, Strada SJ. Activation of mammalian cyclic AMP phosphodiesterases by trypsin. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 527:442-55. [PMID: 215213 DOI: 10.1016/0005-2744(78)90358-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BHK fibroblasts contain two forms of cyclic AMP phosphodiesterase 3':5'-cyclic nucleotide 5'-nucleotidohydrolase EC 3.1.4.17) as analyzed by linear sucrose gradient fractionation; a 3.6-S form (peak I) and a 6.7-S form (peak II). Peak I is specific for cyclic AMP as substrate and displays Michaelis-Menten kinetics with an apparent Km of 2--3 micrometer. Peak II hydrolyzes cyclic GMP and displays anomalous kinetics for cyclic AMP hydrolysis. The activity of isolated peak II for cyclic AMP is increased by storage at 4 degrees C, treatment with trypsin, or treatment with rat brain and BHK fibroblast activator proteins. The activity of isolated peak I is unaffected by these conditions. Linear sucrose gradient fractionation demonstrates that activation of peak II by trypsin leads to the formation of a 3.6-S cyclic AMP-specific enzyme form, possibly peak I. In contrast to BHK fibroblasts (and most other mammalian tissues), rat uterus contains only one form of cyclic nucleotide phosphodiesterase on linear sucrose gradients, a 7-S form capable of hydrolyzing both cyclic AMP and cyclic GMP. Treatment of rat uterine supernatant with trypsin leads to the appearance of a 4-S, cyclic AMP-specific form with properties similar to that of BHK peak I. These data suggest that the kinetically complex, higher molecular weight cyclic nucleotide phosphodiesterases may consist of more than one catalytically active site and that multiple forms of the enzyme arise through dissociative mechanisms, possibly as a means of in vivo regulation.
Collapse
|
18
|
Rangel-Aldao R, Schwartz D, Rubin CS. Rapid assay for cyclic AMP and cyclic GMP phosphodiesterases. Anal Biochem 1978; 87:367-75. [PMID: 210688 DOI: 10.1016/0003-2697(78)90686-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
19
|
Bergstrand H, Lundquist B, Schurmann A. Cyclic nucleotide phosphodiesterase. Partial purification and characterization of a high affinity enzyme activity from human lung tissue. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(19)62332-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
20
|
Fredholm BB, Hedqvist P, Vernet L. Effect of theophylline and other drugs on rabbit renal cyclic nucleotide phosphodiesterase, 5'-nucleotidase and adenosine deaminase. Biochem Pharmacol 1978; 27:2845-50. [PMID: 216371 DOI: 10.1016/0006-2952(78)90199-5] [Citation(s) in RCA: 77] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
21
|
|
22
|
Sakai T, Yamanaka H, Tanaka R, Makino H, Kasai H. Stimulation of cyclic nucleotide phosphodiesterases from rat brain by activator protein, proteolytic enzymes and a vitamin E derivative. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 483:121-34. [PMID: 195621 DOI: 10.1016/0005-2744(77)90014-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|