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At least 19 recordsLinked to original sources
PubMed1988

Cyclic GMP, cyclic AMP, glucose at birth, and maturation of rat liver mitochondria.

The improvement in mitochondrial functions which normally occurs in newborn rat liver in vivo during the few hours following delivery is inhibited by a glucose injection at birth (Meister, R., Comte, J., Baggetto, L., G., Godinot, C. and Gautheron, D.C. (1983) Biochim. Biophys. Acta 722, 36-42). To test whether this improvement could be correlated to changes in cyclic nucleotides, the levels of cAMP and cGMP have been measured during the 2 h following birth. At birth, a short rise followed by a decrease of cAMP occurs, then a significant increase of cAMP level is observed between 45 min and 2 h. The cAMP level for animals injected at birth with glucose is lower than for control animals at each time studied. The cGMP level is not significantly affected in control animals, while in glucose-treated animals a significant decrease of cGMP is observed in the postnatal 2 h. The present work shows also that the glucose-induced inhibition of mitochondrial maturation is mimicked by injection at birth of either 8-Br-cGMP or nitroprusside. The latter transiently increases intracellular cGMP. In contrast, the glucose-induced inhibition is prevented by the injection at birth of either dbcAMP or alkylxanthines together with glucose (Comte, J., Meister, R., Baggetto, L.G., Godinot, C. and Gautheron, D.C. (1986) Biochem. Pharmacol. 35, 2411-2416). It is concluded that the postnatal improvement of mitochondrial functions is stimulated by cAMP and inhibited by cGMP, and that glucose-induced inhibition of the maturation is at least partly supported by a decrease in cAMP but not correlated to an increase in cGMP.

Adenosine Diphosphate↗
PubMed1999

Cyclic GMP and cyclic AMP induced changes in control and hypertrophic cardiac myocyte function interact through cyclic GMP affected cyclic-AMP phosphodiesterases.

We tested the hypothesis that the negative functional effects of cyclic GMP (cGMP) would be greater after increasing cyclic AMP (cAMP), because of the action of cGMP-affected cAMP phosphodiesterases in cardiac myocytes and that this effect would be altered in left ventricular hypertrophy (LVH) produced by aortic valve plication. Myocyte shortening data were collected using a video edge detector, and O2 consumption was measured by O2 electrodes during stimulation (5 ms, 1 Hz, in 2 mM Ca2+) from control (n = 7) and LVH (n = 7) dog ventricular myocytes. cAMP and cGMP were determined by a competitive binding assay. cAMP was increased by forskolin and milrinone (10(-6) M). cGMP was increased with zaprinast and decreased by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxilin-1-one (ODQ) both at 10(-6) and 10(-4) M, with and without forskolin or forskolin + milrinone. Zaprinast significantly decreased percent shortening in control (9 +/- 1 to 7 +/- 1%) and LVH (10 +/- 1 to 7 +/- 1%) myocytes. It increased cGMP in control (36 +/- 5 to 52 +/- 7 fmol/10(5) myocytes) and from the significantly higher baseline value in LVH (71 +/- 12 to 104 +/- 18 fmol/10(5) myocytes). ODQ increased myocyte function and decreased cGMP levels in control and LVH myocytes. Forskolin + milrinone increased cAMP levels in control (6 +/- 1 to 15 +/- 2 pmol/10(5) myocytes) and LVH (8 +/- 1 to 18 +/- 2 pmol/10(5) myocytes) myocytes, as did forskolin alone. They also significantly increased percent shortening. There were significant negative functional effects of zaprinast after forskolin + milrinone in control (15 +/- 2 to 9 +/- 1%), which were greater than zaprinast alone, and LVH (12 +/- 1 to 9 +/- 1%). This was associated with an increase in cGMP and a reduction in the increased cAMP induced by forskolin or milrinone. ODQ did not further increase function after forskolin or milrinone in control myocytes, despite lowering cGMP. However, it prevented the forskolin and milrinone induced increase in cAMP. In hypertrophy, ODQ lowered cGMP and increased function after forskolin. ODQ did not affect cAMP after forskolin and milrinone in LVH. Thus, the level of cGMP was inversely correlated with myocyte function. When cAMP levels were elevated, cGMP was still inversely correlated with myocyte function. This was, in part, related to alterations in cAMP. The interaction between cGMP and cAMP was altered in LVH myocytes.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1990

Evidence for reduced binding of cyclic GMP to cyclic GMP phosphodiesterase in photoreceptors of mice heterozygous for the rd gene.

The binding of radiolabelled cGMP to rod outer segment proteins has been investigated in mice, heterozygous for the recessive rd gene that leads to rod dysplasia. Two binding sites were detected, by Scatchard analysis, in a crude cGMP phosphodiesterase fraction, extracted with an EDTA wash from outer segments. Affinities were normal but the capacity of both was reduced 25-35%. Photoaffinity labelling with 3H-cGMP, followed by SDS PAGE and fluorography, suggested that cGMP PDE was the principal binding component in the extracts. If the finding reflects cGMP binding in situ, it might explain the 30-40% lower than normal level of cGMP found in the +/rd retina. Visual pigment has been regenerated in isolated normal and heterozygotic retinas by the application of active isomers of cis-retinal, and the time course of cGMP recovery to 'dark-adapted' levels monitored. The increase in the concentration of cGMP was significantly delayed as compared to that of rhodopsin. No differences in time course or kinetics of recovery were discerned between the two genotypes.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1983

Regulation of canine heart sarcolemmal Ca2+-pumping ATPase by cyclic GMP.

Cyclic nucleotide modulation of the sarcoplasmic reticulum calcium pump has been recognized for some time. Little is known, however, of cyclic nucleotide effects on the sarcolemmal Ca2+-pump. In sarcolemmal vesicles prepared from ventricular muscle by a recent technique (Jones, L.R., Maddock, S.W. and Besch, H.R. (1980) J. Biol. Chem. 255, 9971-9980) we have demonstrated via Millipore filtration that 10(-8) M and 10(-9) M cyclic GMP depressed the rate of ATP- and Mg2+-dependent 45Ca2+ uptake by 34% and 52%, respectively. Only at millimolar levels did cyclic AMP have any effect and the respective 5'-nucleotides had no effect at all. Parallel measurement of the associated (Ca2+ + Mg2+)-ATPase in the presence of either cyclic or 5'-nucleotides, however, revealed no concomitant depression in ATP hydrolysis. In another series of experiments, the cyclic GMP effect on 45Ca2+ uptake was associated with a significant decrease in the pump Vmax, and at the most effective concentration of cyclic GMP increased the apparent Km for Ca2+. These results suggest that cyclic GMP may depress ventricular Ca2+ efflux by decreasing the enzyme turnover and to a limited extent, decreasing pump affinity for Ca2+. This supports a hypothesis whereby cyclic GMP might modulate both local biochemical and electrophysiological events by an effect on a discrete, regional pool of intracellular Ca2+.

Adenosine Triphosphate↗
PubMed2003

Interaction of caspase-3 with the cyclic GMP binding cyclic GMP specific phosphodiesterase (PDE5a1).

Here, we show that recombinant bovine PDE5A1 is proteolysed by recombinant caspase-3 in in vitro and transfected Cos-7 cells. In addition, the treatment of PDE5A1-transfected Cos-7 and PC12 cells with staurosporine, an apoptotic agent that activates endogenous caspase-3, also induced proteolysis and inactivation of PDE5A1. These findings suggest that there is specificity in the interaction between caspase-3 and PDE5A1 that requires application of an apoptotic stimulus. The potential proteolysis of the [778]DQGD[781] site in PDE5A1 by caspase-3 might affect cGMP's hydrolyzing activity as this is within the boundary of the active site. We therefore created a truncated D781 mutant corresponding exactly to the potential cleavage product. This mutant was expressed equally well compared with the wild-type enzyme in transfected Cos-7 cells and was inactive. Inactivity of the truncated mutant was not due to potential misfolding of the enzyme as it eluted from gel filtration chromatography in the same fraction as the wild-type enzyme. Homology model comparison with the catalytic domain of PDE4B2 was used to probe a functional role for the region in PDE5A1 that might be cleaved by caspase-3. From this, we can predict that a caspase-3-mediated cleavage of the [778]DQGD[781] motif would result in removal of the C-terminal tail containing Q807 and F810, which are potentially important amino acids required for substrate binding.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1991

Endothelial cyclic GMP and cyclic AMP do not regulate the release of endothelium-derived relaxing factor/nitric oxide from bovine aortic endothelial cells.

The present study was designed to investigate whether cyclic GMP or cyclic AMP modulates the release of endothelium-derived relaxing factor/nitric oxide (EDRF/NO) in cultured bovine aortic endothelial cells (BAE cells). BAE cell-conditioned medium was transferred onto rat fetal lung fibroblasts (RFL-6 cells) and the increase in cyclic GMP in these cells was used as a sensitive bioassay of EDRF/NO activity. BAE cells released a material that markedly enhanced cyclic GMP in RFL-6 cells. The synthesis of this substance could be stimulated with bradykinin (10 nM) or Ca++ ionophore A23187 (1 microM) and was completely prevented by treatment of the BAE cells with the EDRF/NO synthesis inhibitors NG-nitro-L-arginine (100 microM) or NG-methyl-L-arginine (1 mM). Addition of hemoglobin (10 microM) or incubation of the RFL-6 detector cells with methylene blue (10 microM) also abolished the cyclic GMP increase in the RFL-6 cells. The release of EDRF/NO by bradykinin and A23187 was accompanied by an approximately 2-fold increase in the cyclic GMP content in the producing BAE cells (in the presence of the cyclic GMP phosphodiesterase inhibitor M&B 22,948, 0.1 mM). Incubation of BAE cells with atrial natriuretic peptide (0.1 microM) or sodium nitroprusside (10 microM) enhanced cyclic GMP content of BAE cells 6.5-fold and 4.1-fold, respectively (in the presence of M&B 22,948, 0.1 mM). These increases in the cyclic GMP levels in BAE cells had no effect on basal or bradykinin- and A23187-stimulated release of EDRF/NO. Bradykinin (10 nM) and A23187 (1 microM) also stimulated prostacyclin production in BAE cells 2.4-fold and 5.6-fold, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Evidence for opposing influences of cyclic GMP and cyclic AMP on force of contraction in mammalian myocardium.

The inotropic effects of the 8-Br-derivatives of cyclic GMP and cyclic AMP were investigated in guinea pig or rat auricles and papillary muscles from cats. In guinea pig auricles, 8-Br-cyclic GMP had a concentration-dependent negative inotropic effect, whereas 8-Br-cyclic AMP had a concentration-dependent positive inotropic effect. A negative inotropic effect of 8-Br-cyclic GMP in rat auricles was obtained with 30 times lower doses than in guinea pig auricles; the pacemaker activity of spontaneously beating rat right auricles did not change in response to 8-Br-cyclic GMP. In cat papillary muscles, 8-Br-cyclic GMP (3 X 10(-4) M) also produced a negative inotropic effect. In contrast, 8-Br-cyclic AMP (3 X 10(-4) M) did not affect force of contraction; however, after pretreatment with the strong phosphodiesterase inhibitor papaverine (2 X 10(-5) M) 8-Br-cyclic AMP (3 X 10(-4) M) had a strong positive inotropic effect also in cat papillary muscles. The results suggest opposite influences of cyclic GMP and cyclic AMP on force of contraction in mammalian myocardium.

Animals↗
PubMed1997

Nitric oxide reduces myocardial contractility in isoproterenol-stimulated rat hearts by a mechanism independent of cyclic GMP or cyclic AMP.

Nitric oxide has been shown to decrease myocardial contractility and O2 consumption. This study was designed to evaluate the hypothesis that nitric oxide-mediated increases in cyclic GMP require elevated cyclic AMP to produce cardiac depression. Using isolated, Langendorff-perfused rat hearts, we determined the effects of intracoronary nitroprusside (NP, 1 and 10 mM) in the absence and presence of isoproterenol (ISO, 10(-8) M) on cardiac function, O2 consumption, cyclic GMP and cyclic AMP. ISO, with and without NP, increased cyclic AMP (from 287 +/- 21 to 477 +/- 33 pmol/g) without altering cyclic GMP. Left-ventricular pressure increased from 97 +/- 12 to 178 +/- 9 mm Hg and dP/dtmax from 1,786 +/- 275 to 4,049 +/- 354 mm Hg/s. NP increased cyclic GMP (from 4 to 30 pmol/g) in both the absence and presence of ISO, but NP did not alter cyclic AMP. Without ISO, NP insignificantly altered left-ventricular pressure; however, in the presence of ISO, NP significantly decreased left-ventricular pressure by -25 +/- 4 mm Hg and decreased dP/dtmax by -619 +/- 142 mm Hg/s. Isoproterenol increased O2 consumption, but the changes with NP were not significant. When this study was repeated in the presence of LY83583, a guanylate cyclase inhibitor, NP still produced cardiac depression in the presence of ISO. Therefore, cardiodepressant effects of NP were only observed against a background of inotropic stimulation with ISO. However, effects of NP on contractility were unrelated to increases in cyclic GMP or cyclic GMP-induced changes in cyclic AMP.

Aminoquinolines↗
PubMed1978

Effects of zinc chloride on the hydrolysis of cyclic GMP and cyclic AMP by the activator-dependent cyclic nucleotide phosphodiesterase from bovine heart.

In the presence of 10 micrometer Ca2+ and 5 mM Mg2+ (or 0.25 mM Mg2+), the addition of 100 micrometer Zn2+, Ni2+, Co2+, Fe2+, Cu2+ or 1 mM Mn2+ resulted in varying degrees of stimulation or inhibition of 10(-6) M cyclic GMP and cyclic AMP hydrolysis by the activator-dependent cyclic nucleotide phosphodiesterase from bovine heart in the absence or presence of phosphodiesterase activator. The substrate specificity of the enzyme was altered under several conditions. The addition of Zn2+ in the presence of 5 mM Mg2+ and the absence of activator resulted in the stimulation of cyclic GMP hydrolysis over a narrow substrate range while reducing the V 65% due to a shift in the kinetics from non-linear with Mg2+ alone to linear in the presence of Zn2+ and Mg2+. Zn2+ inhibited the hydrolysis of cyclic GMP and cyclic AMP in the presence of activator with Ki values of 70 and 100 micrometer, respectively. Zn2+ inhibition was non-competitive with substrate, activator and Ca2+ but was competitive with Mg2+. In the presence of 10 micrometer Ca2+ and activator, a Ki of 15 micrometer for Zn2+ vs. Mg2+ was noted in the hydrolysis of 10(-6) M cyclic GMP. Several effects of Zn2+ are discussed which have been noted in other studies and might be due in part to changes in cyclic nucleotide levels following phosphodiesterase inhibition.

Animals↗
PubMed1986

Evidence against direct involvement of cyclic GMP or cyclic AMP in bacterial chemotactic signaling.

Defects in phosphotransferase chemotaxis in cya and cpd mutants previously cited as evidence of a cyclic GMP or cyclic AMP intermediate in signal transduction were not reproduced in a study of chemotaxis in Escherichia coli and Salmonella typhimurium. In cya mutants, which lack adenylate cyclase, the addition of cyclic AMP was required for synthesis of proteins that were necessary for phosphotransferase transport and chemotaxis. However, the induced cells retained normal phosphotransferase chemotaxis after cyclic AMP was removed. Phosphotransferase chemotaxis was normal in a cpd mutant of S. typhimurium that has elevated levels of cyclic GMP and cyclic AMP. S. typhimurium crr mutants are deficient in enzyme III glucose, which is a component of the glucose transport system, and a regulator of adenylate cyclase. After preincubation with cyclic AMP, the crr mutants were deficient in enzyme II glucose-mediated transport and chemotaxis, but other chemotactic responses were normal. It is concluded that cyclic GMP does not determine the frequency of tumbling and is probably not a component of the transduction pathway. The only known role of cyclic AMP is in the synthesis of some proteins that are subject to catabolite repression.

Adenylyl Cyclases↗
PubMed2000

Cyclic GMP attenuates cyclic AMP-stimulated inotropy and oxygen consumption in control and hypertrophic hearts.

We tested the hypothesis that increasing myocardial cyclic GMP would attenuate cyclic AMP induced positive inotropy and O2 consumption, in part, through changes in cyclic AMP and that renal hypertension-induced cardiac hypertrophy (HYP) would alter this relationship. Anesthetized, open chest rabbits (N = 48) were divided into four groups of control (CON) and HYP animals which received vehicle (VEH), isoproterenol 10(-6)M (ISO), 3-morpholinosyndnonimine 10(-4)M, (SIN-1), or a combination of ISO+SIN-1. Coronary blood flow (microspheres) and O2 extraction (microspectrophotometry) were used to determine O2 consumption in both subepicardium (EPI) and subendocardium (ENDO). Left ventricular change in wall thickness (%) was increased significantly by ISO in both CON (16 +/- 4 to 31 +/- 6) and HYP (17 +/- 2 to 24 +/- 3). Percent change in wall thickness was similar in the CON, SIN-1, and ISO+SIN-1 groups. Myocardial O2 consumption (ml O2/min/100 g) was increased by ISO in CON (10.3 +/- 1.0 to 13.6 +/- 2.0 EPI; 10.9 +/- 1.0 17.1 +/- 1.7 ENDO) and HYP (8.2 +/- 1.4 to 12.3 +/- 2.2 EPI; 6.6 +/- 1.4 to 14.8 +/- 1.8 ENDO). Oxygen consumption was unaffected by SIN-1 in CON and HYP animals. ISO+SIN-1 caused attenuated ISO-induced increases in O2 consumption in CON in EPI and ENDO, and in EPI in HYP. Cyclic GMP (pmol/g) was unchanged by ISO in CON and HYP, and increased by SIN-1 in CON (8.1 +/- 1.3 to 19.2 +/- 2.3 EPI) and HYP (9.1 +/- 1.5 to 12.8 +/- 2.0 EPI). Cyclic GMP remained elevated with ISO+SIN-1 in both groups. Cyclic AMP (pmol/g) was increased significantly by ISO in CON (496 +/- 43 to 725 +/- 106 EPI; 534 +/- 44 to 756 +/- 148 ENDO) and insignificantly in HYP (435 +/- 50 to 566 +/- 35 EPI; 497 +/- 51 to 583 +/- 47 ENDO). Cyclic AMP levels were unaffected by SIN-1 in either group. Isoproterenol induced increases in cyclic AMP were blunted by ISO+SIN-1 in CON (496 +/- 43 to 537 +/- 59 EPI) and not affected in HYP. The current study demonstrated attenuation of cyclic AMP mediated increased inotropy and O2 consumption by increasing cyclic GMP, which appeared, in part, related to cyclic GMP-induced reduction in cyclic AMP. This effect of cyclic GMP on cyclic AMP was not observed in myocardial hypertrophy.

Animals↗
PubMed1985

Atriopeptin II elevates cyclic GMP, activates cyclic GMP-dependent protein kinase and causes relaxation in rat thoracic aorta.

Synthetic atriopeptin II, an atrial natriuretic factor with potent vasodilatory effects, was studied in isolated strips of rat thoracic aorta to determine its actions on contractility, cyclic nucleotide concentrations and endogenous activity of cyclic nucleotide-dependent protein kinases. Atriopeptin II was found to relax aortic strips precontracted with 0.3 microM norepinephrine whether or not the endothelial layer was present. Relaxation to atriopeptin II was closely correlated in a time- and concentration-dependent manner with increases in cyclic GMP concentrations and activation of cyclic GMP-dependent protein kinase (cyclic GMP-kinase). The threshold concentration for all three effects was 1 nM. Atriopeptin II (10 nM for 10 min) produced an 80% relaxation, an 8-fold increase in cyclic GMP concentrations and a 2-fold increase in cyclic GMP-kinase activity ratios. Atriopeptin II did not significantly alter cyclic AMP concentrations or cyclic AMP-dependent protein kinase activity. These data suggest that cyclic GMP and cyclic GMP-kinase may mediate vascular relaxation to a new class of vasoactive agents, the atrial natriuretic factors. Similar effects have been observed with the nitrovasodilator, sodium nitroprusside, and the endothelium-dependent vasodilator, acetylcholine. Therefore, a common biochemical mechanism of action that includes cyclic GMP accumulation and activation of cyclic GMP-kinase may be involved in vascular relaxation to nitrovasodilators, endothelium-dependent vasodilators and atrial natriuretic factors.

Animals↗
PubMed1999

Growth-inhibitory effect of cyclic GMP- and cyclic AMP-dependent vasodilators on rat vascular smooth muscle cells: effect on cell cycle and cyclin expression.

1. The possibility that the antiproliferative effect of cyclic GMP- and cyclic AMP-dependent vasodilators involves an impaired progression of vascular smooth muscle cells (VSMC) through the cell cycle and expression of cyclins, which in association with the cyclin-dependent kinases control the transition between the distinct phases of the cell cycle, was examined. 2. FCS (10%) stimulated the transition of quiescent VSMC from the G0/G1 to the S phase (maximum within 18-24 h and then to the G2/M phase (maximum within 22-28 h). Sodium nitroprusside and 8-Br-cyclic GMP, as well as forskolin and 8-Br-cyclic AMP markedly reduced the percentage of cells in the S phase after FCS stimulation. 3. FCS stimulated the low basal protein expression of cyclin D1 (maximum within 8-24 h) and E (maximum within 8-38 h) and of cyclin A (maximum within 14-30 h). The stimulatory effect of FCS on cyclin D1 and A expression was inhibited, but that of cyclin E was only minimally affected by the vasodilators. 4. FCS increased the low basal level of cyclin D1 mRNA after a lag phase of 2 h and that of cyclin A after 12 h. The vasodilators significantly reduced the FCS-stimulated expression of cyclin D1 and A mRNA. 5. These findings indicate that cyclic GMP- and cyclic AMP-dependent vasodilators inhibit the proliferation of VSMC by preventing the progression of the cell cycle from the G0/G1 into the S phase, an effect which can be attributed to the impaired expression of cyclin D1 and A.

Animals↗
PubMed1973

Effects of bradykinin and indomethacin on cyclic GMP and cyclic AMP in lung slices.

Bradykinin, 1-100 mug/ml, produced a rapid rise in the concentration of 3':5'-guanosine monophosphate (cyclic GMP) and 3':5'-adenosine monophosphate (cyclic AMP) in slices of guinea pig lung. Concentrations of both nucleotides reached a maximum in about 2 min, then declined to a basal levels in 6-12 min. The transient nature of the effect was presumbaly due to the rapid destruction of bradykinin as evidenced by (1) reaccumulation of nucleotides when bradykinin was added a second time, and (2) potentiation of the bradykinin effects by pyroGlu-Lys-Trp-Ala-Pro, a peptide that inhibits inactivation of bradykinin by kininase. It has been reported elsewhere that histamine, prostaglandins E(1) and E(2), and beta-adrenergic stimulation can cause accumulation of cyclic AMP in lung slices without affecting cyclic GMP concentration, whereas acetylcholine increases the concentrations of both cyclic GMP and cyclic AMP. Thus it was possible that the effects of bradykinin were indirect, i.e., secondary to release of one or more of these compounds. Promethazine (an antihistamine), propranolol (a beta-adrenergic blocking agent) and atropine (an anticholinergic agent) did not alter basal cyclic nucleotide concentrations or the effects of bradykinin. Two inhibitors of prostaglandin synthesis, indomethacin and aspirin, which alone were without effect, in the presence of bradykinin completely prevented the rise in cyclic AMP but did not interfere with cyclic GMP accumulation. Similarly, the effect of acetylcholine on cyclic AMP was abolished by indomethacin while that on cyclic GMP was unaltered. We suggest that in lung and probably in other tissues, bradykinin, acetylcholine, and perhaps other stimuli enhance the synthesis and release of prostaglandins as one of the consequences of their effects on cyclic GMP metabolism.

Acetylcholine↗
PubMed1979

Cyclic GMP and cyclic AMP changes in response to folic acid pulses during cell development of Dictyostelium discoideum.

Folic acid pulses induced developmental processes in agip 71, a morphogenetic mutant of Dictyostelium discoideum, strain Ax-2. Cells that had received folic acid pulses were able to form EDTA-stable cell aggregates and to complete full differentiation to fruiting bodies. In these cells no autonomous periodic activities were observed by light scattering. Folic acid pulses elicited increases in the concentrations of cyclic GMP and cyclic AMP. In undifferentiated cells, folic acid caused a rapid increase in the level of cyclic GMP without a significant change in the level of cyclic AMP. In an advanced developmental state folic acid caused an increase in cyclic AMP in addition to two successsive peaks of cyclic GMP. Experiments performed with the parent strain, Ax-2, also showed that during the development towards aggregation competence, cells acquired the ability to produce a cyclic AMP peak in response to folic acid.

Cell Adhesion↗