scholarly journals Effect of buffer composition on binding of adenosine 3′:5′-cyclic monophosphate by bovine adrenal extracts

1977 ◽  
Vol 166 (3) ◽  
pp. 553-557 ◽  
Author(s):  
J Linkola ◽  
F Fyhrquist ◽  
T H Weber ◽  
L Puutula
Keyword(s):  
Environmental Factors ◽  
Cyclic Amp ◽  
Binding Affinity ◽  
Cyclic Gmp ◽  
Disodium Salt ◽  
Binding Material ◽  
Second Messenger Systems ◽  
Buffer Composition ◽  
Fold Excess ◽  
High Binding Affinity

The binding of cyclic [3H] AMP by bovine adrenal extracts was studied in different buffer systems; 50 mM-Tris/HCl, pH 7.5, buffer containing 4mM-EDTA (disodium salt) offered advantages such as low non-specific interference and high binding affinity. 2-Mercaptoethanol decreased, but EDTA and theophylline increased, the specificity of cyclic [3H]AMP binding as expressed by the displacement of cyclic [3H]AMP by a 1000-fold excess of unlabelled cyclic GMP. The study indicated heterogeneity of the binding material. Mg2+-dependent binding may be eliminated in Tris/EDTA buffer. The heterogeneity and the specificity of intracellular cyclic AMP binders and their dependence in environmental factors should be considered in the evaluation of cyclic AMP binding and second-messenger systems.

scholarly journals Second-messenger systems underlying amine and peptide actions on cardiac muscle in the horseshoe crab Limulus polyphemus

1989 ◽  
Vol 145 (1) ◽  
pp. 419-437 ◽  
Author(s):  
J. R. Groome ◽  
W. H. Watson
Keyword(s):  
Cyclic Amp ◽  
Cardiac Muscle ◽  
Cyclic Gmp ◽  
Phosphodiesterase Inhibitor ◽  
Second Messenger ◽  
Muscle Contractility ◽  
Contraction Amplitude ◽  
Second Messenger Systems ◽  
Biochemical Mechanisms ◽  
Cardiac Muscle Fibers

The biochemical mechanisms by which octopamine, catecholamines and the peptide proctolin exert their actions on Limulus cardiac muscle were investigated. Amines produced long-lasting increases in the amplitude of contractions evoked by electrical stimulation. At 10(−5) mol l-1, the apparent order of potency for amine-induced increases in evoked contraction amplitude was dopamine approximately equal to octopamine greater than norepinephrine approximately equal to epinephrine. At this dose, amines produced long-lasting increases in the levels of cyclic AMP (octopamine greater than dopamine approximately equal to norepinephrine approximately equal to epinephrine), but not of cyclic GMP, in Limulus cardiac muscle. Like the amines, the adenylate cyclase activator forskolin enhanced cardiac muscle contractility and increased levels of cyclic AMP, but not of cyclic GMP. The phosphodiesterase inhibitor IBMX produced a transient increase in cardiac muscle contractility, but typically produced long-lasting negative inotropy. This agent increased levels of both cyclic AMP and cyclic GMP in Limulus cardiac muscle. Proctolin and the protein kinase C activator phorbol dB increased the contraction amplitude of the intact heart and the electrically stimulated myocardium. These compounds, as well as dopamine, elicited sustained contractures and rhythmic contractions when applied to deganglionated Limulus cardiac muscle rings. Unlike the amines, proctolin and phorbol dB did not increase cardiac muscle cyclic AMP levels. These results suggest that several second-messenger systems may be utilized by amines and peptides to produce excitatory actions on cardiac muscle fibers of the Limulus heart. Cyclic AMP appears to be an important second messenger underlying the effects of amines to enhance cardiac muscle contractility. Pharmacological data suggest that proctolin may alter cardiac muscle contractility and excitability by a mechanism which involves the phosphatidylinositol pathway. Dopamine, unlike the other amines, produces a number of proctolin-like effects and may activate both the cyclic AMP and the phosphatidylinositol systems in Limulus cardiac muscle.

Effect of Cyclic AMP and Cyclic GMP on Thromboplastin (Factor III) Synthesis in Human Monocytes In Vitro

1983 ◽  
Vol 50 (04) ◽  
pp. 804-809 ◽  
Author(s):  
Torstein Lyberg
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Immune Complexes ◽  
Phosphodiesterase Inhibitors ◽  
Inhibitory Effect ◽  
Intracellular Camp ◽  
Human Monocytes ◽  
Purified Protein Derivative ◽  
A 23187

SummaryHuman monocytes in vitro respond to various agents (immune complexes, lectins, endotoxin, the divalent ionophore A 23187, 12-0-tetradecanoyl-phorbol 13-acetate [TPA], purified protein derivative [PPD] of Bacille Calmette-Guerin) with an increased synthesis of the protein component of thromboplastin. The effect of cyclic AMP and cyclic GMP on this response has been studied. Dibutyryl-cyclic AMP, prostaglandin E1 and the phosphodiesterase inhibitors 3-butyl-1-methyl-xanthine (MIX) and rac -4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (Ro 201724), separately and in combination have a pronounced inhibitory effect on the response to immune complexes and PPD, and a moderate effect on the response to endotoxin and lectins. The effect on TPA response and on the response to A 23187 was slight. Dibutyryl-cyclic GMP (1 mM) gave a slight inhibition of the TPA arid IC response, but had essentially no effect on the response to other inducers. The intracellular cAMP level increased when monocytes were incubated with IC, TPA or A 23187 followed by a decrease to basal levels within 1-2 hr, whereas lectin (PHA) and PPD did not induce such changes. The cAMP response to endotoxin varied. Stimulation with IC induced an increase in monocyte cGMP levels, whereas the other stimulants did not cause such changes.

scholarly journals Cellular localization of cyclic AMP and cyclic GMP in rat bone marrow

1979 ◽  
Vol 29 ◽  
pp. 85
Author(s):  
Nobuyoshi Yoshida ◽  
Kohtaro Taniyama ◽  
Chikako Tanaka
Keyword(s):  
Bone Marrow ◽  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Cellular Localization ◽  
Rat Bone

Melanocyte-stimulating hormone and the regulation of tyrosinase activity in hair follicular melanocytes of the mouse

1986 ◽  
Vol 111 (2) ◽  
pp. 225-232 ◽  
Author(s):  
S. A. Burchill ◽  
A. J. Thody
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Hair Growth ◽  
Yellow Pigment ◽  
Tyrosinase Activity ◽  
Melanocyte Stimulating Hormone ◽  
Golden Yellow ◽  
Skin Explants ◽  
Low Levels ◽  
Old Mice

ABSTRACT Skin tyrosinase activity increases during hair growth in C3H–HeA*vy mice and reaches higher levels in young (30- to 35-day-old) mice when the hair follicular melanocytes synthesize the black pigment, eumelanin, than in older (6-month-old) mice when they produce the golden yellow pigment, phaeomelanin. To examine the regulation of the melanocytes at these different stages we have compared the effect of α-MSH and other agents that act, through cyclic AMP-dependent mechanisms, on skin tyrosinase activity in both young and old mice during hair growth, initiated by plucking. Daily administration of α-MSH, isoprenaline or theophylline increased coat darkness, and skin tyrosinase activity in the younger mice 7–9 days after plucking, but they were ineffective in the older mice. Similarly α-MSH, 8-bromo-cyclic AMP or theophylline increased tyrosinase activity in skin explants from the younger mice incubated for up to 24 h but had no effect in explants from older mice. Cyclic GMP had no effect on tyrosinase activity in skin explants from both young and old mice. It is suggested that whereas cyclic AMP-dependent mechanisms may operate to regulate tyrosinase activity in the hair follicular melanocytes of younger mice that produce eumelanin these systems may not operate in the older mice when these melanocytes synthesize phaeomelanin. Phaeomelanin synthesis, unlike that of eumelanin, may not depend upon tyrosinase and its regulation by cyclic AMP and this could explain the low levels of this enzyme in the skin and its failure to respond to α-MSH and other activators of the cyclic AMP system during periods of phaeomelanin production. J. Endocr. (1986) 111, 225–232

scholarly journals Herb-target virtual screening and network pharmacology for prediction of molecular mechanism of Danggui Beimu Kushen Wan for prostate cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hong Li ◽  
Andrew Hung ◽  
Angela Wei Hong Yang
Keyword(s):  
Prostate Cancer ◽  
Binding Affinity ◽  
Molecular Mechanisms ◽  
Biological Activities ◽  
Tight Binding ◽  
Experimental Studies ◽  
Network Pharmacology ◽  
High Morbidity ◽  
High Binding ◽  
High Binding Affinity

AbstractProstate cancer (PCa) is a cancer that occurs in the prostate with high morbidity and mortality. Danggui Beimu Kushen Wan (DBKW) is a classic formula for patients with difficult urination including PCa. This study aimed to investigate the molecular mechanisms of DBKW for PCa. We obtained DBKW compounds from our previous reviews. We identified potential targets for PCa from literature search, currently approved drugs and Open Targets database and filtered them by protein–protein interaction network analysis. We selected 26 targets to predict three cancer-related pathways. A total of 621 compounds were screened via molecular docking using PyRx and AutoDock Vina against 21 targets for PCa, producing 13041 docking results. The binding patterns and positions showed that a relatively small number of tight-binding compounds from DBKW were predicted to interact strongly and selectively with three targets. The top five high-binding-affinity compounds were selected to generate a network, indicating that compounds from all three herbs had high binding affinity against the 21 targets and may have potential biological activities with the targets. DBKW contains multi-targeting agents that could act on more than one pathway of PCa simultaneously. Further studies could focus on validating the computational results via experimental studies.

scholarly journals The Detection of Bovine Estrus by Lactoferrin Monoclonal Antibody

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1582
Author(s):  
Jihwan Lee ◽  
Suhyun Lee ◽  
Younbae Park ◽  
Seokhyun Lee ◽  
Seungmin Ha ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Binding Affinity ◽  
Reproductive Performance ◽  
Economic Loss ◽  
Cervical Mucus ◽  
Female Rats ◽  
Economic Damage ◽  
Bovine Lactoferrin ◽  
Estrous Synchronization ◽  
High Binding Affinity

To improve reproductive performance in cattle, the accurate detection of estrus and optimization of insemination relative to ovulation are necessary. However, poor heat detection by farm staff leads to a decreased conception rate, thus inflicting economic damage to the beef and dairy industries. This study aimed to develop monoclonal antibodies (mAb) that can specifically bind to the bovine lactoferrin (bLF) protein, which we have previously demonstrated to be overexpressed in bovine cervical mucus during estrus. Female rats were intraperitoneally immunized with bLF protein as the antigen. Anti-bLF mAbs were then purified by affinity chromatography, and their binding affinity for the bLF antigen was examined using ELISA. We found a high binding affinity between mAbs and bLF. Finally, we developed a rapid bovine heat detection kit using the anti-bLF mAbs that we generated and tested on cervical mucus from 12 cows (estrous synchronization, n = 2; natural cycling, n = 10). We found that the kits accurately detected estrus. Overall, our fabricated heat detection kit based on rat anti-bLF mAbs could pave the way for the development of potent tools for heat detection devices for dairy cattle, thereby preventing economic loss.

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