Cyclic Nucleotide Levels during Spontaneous Uterine Contractions

1974 ◽  
Vol 52 (3) ◽  
pp. 763-767 ◽  
Author(s):  
Jack Diamond ◽  
Diane K. Hartle
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Cyclic Nucleotide ◽  
Spontaneous Contraction ◽  
Rat Uterus ◽  
Cyclic Monophosphate ◽  
Tissue Levels ◽  
Uterine Contractions ◽  
Spontaneous Contractions ◽  
Isolated Rat

Tissue levels of adenosine 3′,5′-cyclic monophosphate (cyclic AMP) and guanosine 3′,5′-cyclic monophosphate (cyclic GMP) were determined in uterine muscles frozen at various points during spontaneous contraction–relaxation cycles. No significant changes in cyclic nucleotide levels were detected at any of the stages of contraction studied. Exposure of uterine segments to 1 μM isoproterenol resulted in an eightfold increase in cyclic AMP levels but no change in cyclic GMP, whereas exposure to 2 mM theophylline resulted in a doubling of cyclic GMP levels and a 42% increase in cyclic AMP content. Thus, the methods used were capable of detecting changes in cyclic nucleotide levels when they did occur. It was concluded that changes in cyclic nucleotide levels do not play a role in the initiation or regulation of spontaneous contractions of isolated rat uterus.

Effects of Potassium Chloride and Smooth Muscle Relaxants on Tension and Cyclic Nucleotide Levels in Rat Myometrium

1975 ◽  
Vol 53 (6) ◽  
pp. 1099-1107 ◽  
Author(s):  
Jack Diamond ◽  
Thomas G. Holmes
Keyword(s):  
Smooth Muscle ◽  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Smooth Muscle Contraction ◽  
Relaxed Controls ◽  
Cyclic Monophosphate ◽  
Tissue Levels ◽  
Contraction And Relaxation ◽  
Total Tissue ◽  
Uterine Relaxation

Ten minutes after KCl-depolarization of rat myometrial strips, at which time the muscles were in a state of sustained contracture, tissue levels of adenosine 3′,5′-cyclic monophosphate (cyclic AMP) were increased by approximately 40% over relaxed controls, and levels of guanosine 3′,5′-cyclic monophosphate (cyclic GMP) were decreased by 40%. At this point both nitroglycerin (4 × 10−4 M) and papaverine (2 × 10−5 M) were capable of relaxing the depolarized muscles without significantly increasing cyclic AMP levels. Isoproterenol, in concentrations from 5 × 10−9 M to 10−6 M, relaxed the depolarized muscles and significantly increased tissue levels of cyclic AMP. However, the magnitudes of the cyclic AMP increases seen after the lower concentrations of isoproterenol were small relative to the increases observed during KCl-contracture alone. For example, the 40% elevation of cyclic AMP seen 10 min after KCl-depolarization did not cause the muscles to relax, whereas 5 × 10−9 M isoproterenol caused relaxation with an increase in cyclic AMP levels of only 16% over depolarized controls. It was concluded that changes in total tissue levels of cyclic AMP were not responsible for the uterine relaxation caused by nitroglycerin, papaverine or isoproterenol in these experiments. Cyclic GMP levels in the depolarized muscles were not significantly changed by isoproterenol or papaverine but were increased approximately 80% by nitroglycerin.The above results are not consistent with the previously suggested roles for cyclic GMP and cyclic AMP as mediators of smooth muscle contraction and relaxation, respectively.

Radioimmunoassay for adenosine 3', 5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate in human blood, urine, and cerebrospinal fluid.

1977 ◽  
Vol 23 (3) ◽  
pp. 576-580 ◽  
Author(s):  
M L Goldberg
Keyword(s):  
Cerebrospinal Fluid ◽  
Cyclic Amp ◽  
Human Blood ◽  
Cyclic Gmp ◽  
Cyclic Nucleotides ◽  
Cyclic Nucleotide ◽  
Cyclic Monophosphate ◽  
Specificity And Sensitivity ◽  
Analytical Recovery ◽  
Highly Sensitive

Abstract I describe a highly sensitive and very specific assay for cyclic AMP and cyclic GMP in body fluids. An adaptation of the method of Harper and Brooker [j. cyclic Nucleotide Res. 1,207 (1975)], its advantage lies in the fact that the simple acetylation of the samples--a procedure developed by these workers--greatly increases specificity and sensitivity beyond those of previous methods and permits the measurement of femtomole quantities of both cyclic nucleotides without prepurification. Because the range of the cyclic AMP assay is 20-200 fmol, and that of cyclic GMP 10-15 fmol, experiments can be performed with use of only microliters of fluid. The method requires no extraction and thus no complicated corrections are necessary for analytical recovery.

Follicle-stimulating hormone-induced prostaglandin E formation in isolated rat ovarian theca

1983 ◽  
Vol 97 (1) ◽  
pp. 43-49 ◽  
Author(s):  
U. Zor ◽  
B. Strulovici ◽  
R. Braw ◽  
H. R. Lindner ◽  
A. Tsafriri
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Follicle Stimulating Hormone ◽  
Fold Increase ◽  
Prostaglandin E ◽  
Β Subunit ◽  
Biochemical Effects ◽  
Isolated Rat ◽  
Stimulating Hormone

The aim of this study was to search for direct biochemical effects of highly purified FSH on isolated ovarian follicular theca in vitro. Granulosa cells (GC; approximately 1 × 105 cells per follicle) were flushed from isolated follicles of pro-oestrous rats. The remaining theca layer and the isolated GC were incubated with highly purified ovine FSH. Prostaglandin E (PGE) accumulation was measured by radioimmunoassay. Follicle-stimulating hormone induced a 15-fold increase in PGE accumulation over the basal level in the follicular theca, the stimulated rate exceeding threefold that observed in the GC fraction derived from the same follicle. Follicle-stimulating hormone caused no significant increase in cyclic AMP level or steroidogenesis in the theca layer, but was active on these parameters in the GC. In contrast, LH increased the accumulation of cyclic AMP, progesterone and testosterone, as well as of PGE, in follicular theca. Exogenous 8-bromo cyclic AMP or cyclic GMP also stimulated PGE production in follicular theca or GC, but FSH was without any effect on the level of endogenous cyclic GMP in GC or follicular theca. Antibodies to FSH prevented the effect of FSH (but not that of LH) on PGE formation by follicular theca and GC, while antibodies to the β-subunit of LH blocked the effect of LH but not of FSH. We conclude that highly purified FSH has a stimulatory effect on PGE formation by the follicular theca.

scholarly journals Growth hormone, cyclic nucleotides and the rapid control of translation in heart muscle

1975 ◽  
Vol 152 (3) ◽  
pp. 583-592 ◽  
Author(s):  
J Mowbray ◽  
J A Davies ◽  
D J Bates ◽  
C J Jones
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Cyclic Nucleotides ◽  
Cyclic Nucleotide ◽  
Precursor Pool ◽  
Growth Hormone Action ◽  
Constant Rate ◽  
The Individual

Perfused rat heart incorporated L-[14C]tyrosine into protein at a constant rate for up to 75 min. A purified bovine growth-hormone preparation (1 mug/ml) stimulated the incorporation to a new constant rate that was more than three times the control rate by 10 min after hormone addition to perfusate. The hormone, however, did not alter the intracellular tracer amino acid pool, and the relationship of this to the aminoacyl-tRNA precursor pool is discussed. It is concluded that the increased incorporation largely reflected a rapid increase in protein synthesis at the ribosomes. Measurements of cyclic nucleotide contents during the perfusion showed that these appeared to vary in a systematic way during the perfusion. This strands in contrast with the constant values given by several other parameters measured in this preparation. Futher, the cyclic nucleotide variation seems to be independent of external effectors. The steady-state performance of the heart correlates more closely the [cyclic AMP]/[cyclic GMP] ratio than with the content of the individual cyclic nucleotides. At 10 min after the addition of growth hormone a slight decrese in cyclic AMP content and a large decrease in cyclic GMP were found, suggesting that the hormone's effect in stimulating protein synthesis may be mediated by a decrease in cyclic nucleotide concentrations or an increase in the [cyclic AMP]/[cyclic |p] ratio. The findings are also consistent with an intracellularly directed role for these nucleotides, and the possibility that the cyclic nucleotide changes are an indirect result of growth-hormone action is discussed.

Influence of dopamine on cyclic nucleotide enzymes in bovine retinal membrane fractions

1993 ◽  
Vol 10 (6) ◽  
pp. 991-996 ◽  
Author(s):  
Ari Sitaramayya ◽  
Lorraine Lombardi ◽  
Alexander Margulis
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Cyclic Nucleotide ◽  
D2 Receptors ◽  
D1 Receptors ◽  
Metabolizing Enzymes ◽  
D2 Agonist ◽  
Hydrolysis Of ◽  
Cyclic Amp Synthesis

AbstractDopamine is a major neurotransmitter and neuromodulator in vertebrate retina. Although its pharmacological and physiological actions are well understood, the biochemical mechanisms of its signal transduction are less clear. Acting via D1 receptors, dopamine was shown to increase cyclic AMP levels in intact retina and to activate adenylate cyclase in retinal homogenates. The action via activation of D2 receptors is controversial: it was reported to decrease cyclic AMP levels in intact retina but inhibition of cyclase could not be demonstrated in retinal homogenates; also it was reported to activate rod outer segment cyclic GMP phosphodiesterase in vitro but did not decrease cyclic GMP levels in aspartate-treated retinas. We made an attempt to fractionate bovine retinal membranes and to investigate the effects of dopamine, via Dl and D2 receptors, on the synthesis and hydrolysis of cyclic AMP and cyclic GMP. Activation of cyclic AMP synthesis was noted in all fractions, but no effects were evident on cyclic nucleotide hydrolysis or cyclic GMP synthesis in any fraction. Also, D2 agonist did not inhibit cyclic AMP synthesis. These observations suggest that D2 receptors may not be directly coupled to cyclic nucleotide metabolizing enzymes in bovine retina.

scholarly journals Dibutyryladenosine 3′:5′-cyclic monophosphate-mediated changes in rat cells involve macromolecular alterations in vinblastine-precipitable proteins

1978 ◽  
Vol 174 (3) ◽  
pp. 1071-1074
Author(s):  
A T Meza ◽  
M Rieber
Keyword(s):  
Molecular Weight ◽  
Cyclic Amp ◽  
Cell Cultures ◽  
Cyclic Nucleotide ◽  
Dibutyryl Cyclic Amp ◽  
Cyclic Monophosphate ◽  
Three Components

ts-NT3-KR rat cell cultures show the loss of three components in the molecular-weight region 200,000–250,000 when exposed to dibutyryl cyclic AMP, under conditions of both restriction and expression of the transformed phenotype. Vinblastine is able to precipitate preferentially from control cultures the species that are decreased by exposure to the cyclic nucleotide. Serum-starved cultures exposed to dibutyryl cyclic AMP reveal differences in their vinblastine precipitates, depending on whether the expression of the transformation phenotype is restricted or not.

scholarly journals Immunofluorescent localization of cyclic nucleotide-dependent protein kinases on the mitotic apparatus of cultured cells.

1980 ◽  
Vol 87 (2) ◽  
pp. 336-345 ◽  
Author(s):  
C L Browne ◽  
A H Lockwood ◽  
J L Su ◽  
J A Beavo ◽  
A L Steiner
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Kinases ◽  
Cyclic Gmp ◽  
Cyclic Nucleotides ◽  
Mitotic Spindle ◽  
Cyclic Nucleotide ◽  
Dependent Protein Kinase ◽  
Mitotic Apparatus ◽  
Dependent Protein

Cyclic nucleotides and cyclic nucleotide-dependent protein kinases have been implicated in the regulation of cell motility and division, processes that depend on the cell cytoskeleton. To determine whether cyclic nucleotides or their kinases are physically associated with the cytoskeleton during cell division, fluorescently labeled antibodies directed against cyclic AMP, cyclic GMP, and the cyclic nucleotide-dpendent protein kinases were used to localize these molecules in mitotic PtK1 cells. Both the cyclic GMP-dependent protein kinase and the type II regulatory subunit of the cyclic AMP-dependent protein kinase were localized on the mitotic spindle. Throughout mitosis, their distribution closely resembled that of tubulin. Antibodies to cyclic AMP, cyclic GMP, and the type I regulatory and catalytic subunits of the cyclic AMP-dependent protein kinase did not label the mitotic apparatus. The association between specific components of the cyclic neucleotide system and the mitotic spindle suggests that cyclic nucleotide-dependent phosphorylation of spindle proteins, such as those of microtubules, may play a fundamental role in the regulation of spindle assembly and chromosome motion.

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