生物化学技术

A large number of hormones, neurotransmitters, and odorants exert their effects on cells by triggering changes in intracellular levels of cyclic adenosine monophosphate (cAMP). Although the effector proteins that bind cAMP have been identified, it is not known how this single messeng ...

PDE6 in rod and cone photoreceptors is the principal effector of phototransduction. It is kept at a very low activity level in the dark, and in the light it is strongly activated by the guanosine 5′-triphosphate-bound form of the α-subunit of the G protein, transducin. Both transducin and PDE6 are perip ...

The second messenger cyclic guanosine 5′-monophosphate (cGMP) plays a key role in the control and regulation of a steadily increasing number of diverse physiological processes. As the appreciation of the importance of understanding the cGMP signaling pathway has grown, so has the aware ...

Phosphodiesterases (PDEs) hydrolyze the second messengers cyclic adenosine monophosphate (cAMP) and cyclic guanosine 5′-monophosphate (cGMP) and play a crucial role in the termination and spatial segregation of cyclic nucleotide signals. Despite a wealth of molecular infor ...

Cyclic nucleotide phosphodiesterases (PDEs), which are ubiquitously distributed in mammalian tissues, play a major role in cell signaling by hydrolyzing cyclic adenosine 3′,5′-monophosphate and cyclic guanosine 3′,5′-monophosphate. Owing to their diversity, which allows s ...

Ca2+/calmodulin (CaM)-stimulated phosphodiesterases (PDEs) constitute a large family (PDE1 family) of enzymes. All members of the PDE1 family can be stimulated by Ca2+ in the presence of CaM in vitro. It has been shown that the Ca2+/CaM-stimulated PDE activity present in the vessel wall or vascu ...

In this chapter, we describe a protocol for the localization of the cyclic guanosine 3′,5′-monophosphate-specific phosphodiesterase type 9 (PDE9) mRNA in the adult rat brain that uses digoxigenin-labeled riboprobes in a nonradioactive in situ hybridization (ISH). The three differe ...

Polyunsaturated fatty acids undergo in vivo oxidative damage called lipid peroxidation, breaking down to lipid hydroperoxides and various secondary products (1). Increase in lipid peroxides have been reported, for example, in radiation damage, diabetes, hyperlipidemia, and va ...

The level of lipid peroxides in serum or plasma has been found to be increased in various diseases (1), especially in vascular disorders such as angiopathy in diabetes (2), atherosclerosis (3), and apoplexy (4).

During the last several years, it has become increasingly apparent that oxidation of low density lipoproteins (LDL) takes place in vivo as a key event in the development of human atherosclerosis (1,2) and vascular dysfunction (3,4). Thus, many laboratories have focused their interest on the in v ...

Membrane phospholipids contain polyunsaturated fatty-acid side chains esterified to phosphoglycerol. These polyunsaturated fatty acyl esters are easily oxidable lipids. A sensitive method for determination of lipid peroxidation is of considerable interest. Usually l ...

Phospholipids and cholesterol are the lipid component of cellular and subcellular membranes and are transported primarily (65%) in low-density lipoproteins (1). The fatty acids of these compounds are easily attacked by reactive oxygen species leading to the formation of their respe ...

Lipid peroxidation is an autocatalytic free radical-mediated chemical mechanism in which polyunsaturated fatty acids (PUFA) undergo oxidation to form lipid hydroperoxide (LHP). Increased lipid peroxidation has been implicated in many disease conditions including acute m ...

Methylguanidine (MG) was first discovered in the serum and urine of uremic patients (1). Increased synthesis of MG and its toxicity has been implicated as a potent uremic toxin (2).

Profiling of hippocampal peptides by reversed-phase HPLC (RP-HPLC) was used as a tool for identifying molecular events associated with neuro-degeneration following global cerebral i ischemia . Global cerebral ischemia is known to cause impairment of working memory, but not refere ...

Oxidative stress has been implicated in the etiology of many pathological states and known to result in DNA damage. Oxidative DNA damage can lead to mutagenesis (1–3) and has been associated with aging (4), diabetes mellitus (5), inflammatory disease (1) and carcinogenesis (1–3,6). The 8-hydro ...

Nitric oxide (NO) is an important bio-regulatory molecule in the nervous, immune and cardiovascular systems. The physiological involvement of NO in neuronal transmission, control of vascular tone, and immune response-induced cytostasis as well as the deleterious effects associ ...

Phospholipases A2 (PLA2) catalyze the hydrolysis of the ester bond at the sn-2 position of phospholipids to generate the lysophospholipid and free fatty acid (1). Several classes of PLA2s have been identified (2). They include the low molecular weight-secreted enzymes, which demonstrate a ...

A variety of oxidative stress-inducing agents, such as metals, ultra-violet (UV) light, heme, and hemoglobin have been implicated in the pathogenesis of the inflammatory process. The cellular response to such agents involves the production of a number of soluble mediators including acu ...

A biochemical paradox that has been observed for many years is now becoming understood: O2, essential for the aerobic life forms, can be inappropriately metabolized, becoming toxic to an organism. Mammals derive most of their cellular adenosine triphosphate (ATP) from the controlled fou ...