The cyclic nucleotides, cyclic AMP and cyclic GMP, like intracellular calcium, are involved in a vast array of intracellular signaling processes. But knowledge of the cellular and subcellular concentrations of cAMP and cGMP, and of the kinetics and spatial distributions of the changes of their concentration in situ, have lagged far behind our knowledge of the corresponding features of calcium s...

Background Soluble guanylyl cyclase (sGC) constitutes a family of enzymes that catalyses the cyclization of guanosine 5’-triphosphate (GTP) to guanosine 3’,5’-cyclic monophosphate (cGMP). The heterodimeric hemoprotein is activated by nitric oxide and mediates a wide range of physiological effects like regulation of blood pressure and neuronal cell development. sGC is an important target for the...

Cyclic nucleotides cAMP and cGMP are among the main molecules that control maturation of mammal oocytes. The in vitro simulated physiological oocyte (SPOM) method was used to model accumulation oocyte. In current study, we preincubated oocytes cows (not primed with FSH) modulators: N 6,2’-O-dibutyryladenosine 3’,5’-cyclomonophosphate (dbcAMP) 3-isobutyl-1-methylxanthine (IBMX). use SPOM increas...

Like many freely moving cells, Walker 256 carcinosarcoma cells respond to chemotactic stimuli. Since cyclic nucleotides are involved in the chemotaxis of other cells, we have examined the action of several nucleosides and nucleotides as chemoattractants and as modulators of tumor cell movement. We have also studied the effect of chemoattractants and prostaglandins on intracellular cyclic nucleo...

Previous experimental studies suggest that bile salt-induced colonic fluid secretion is mediated by adenosine 3':5'-phosphate (cyclic AMP). Two biopsy specimens of colonic mucosa were obtained endoscopically before and after different periods of therapy (five, 10, or 15 days), from each of 21 patients receiving chenodeoxycholic acid. A rise of cyclic AMP intracellular levels was found, but only...

The soluble high Km form of cyclic nucleotide phosphodiesterase (EC 3.4.1.17) was purified over 2000-fold from bovine brain homogenates principally using blue dextran-Sepharose chromatography. The purified protein has a specific enzymic activity of 167 units/mg and appears homogeneous when examined by polyacrylamide gel electrophoresis. The enzyme has a molecular weight of 1.26 +/- 0.05 x 10(5)...

In developing Dictyostelium discoideum cells, binding of cyclic AMP to the chemotactic receptor has been shown to oscillate. These oscillations represent cycles of activation, adaptation and deadaptation of the cyclic AMP receptor system. We studied the molecular basis of these oscillatory changes in cyclic AMP receptor binding. We developed a rapid method of lysing cells during the course of t...

Transient ischemia is known to lead to a long-lasting depression of cerebral metabolic rate and blood flow and to an attenuated metabolic and circulatory response to physiological stimuli. However, the corresponding responses to induced seizures are retained, demonstrating preserved metabolic and circulatory capacity. The objective of the present study was to explore how a preceding period of i...

• Nucleic acid precursors: nucleotides make up the monomeric units of DNA and RNA. • Energy-transfer molecules: adenosine triphosphate (ATP) is the major source of cellular chemical energy. • Physiologic mediators: cyclic adenosine monophosphate (cAMP) acts as second messenger; cyclic guanosine monophosphate (cGMP) regulates many cellular events; adenosine is known to be a potent vasodilator; g...