Stimulation of high-affinity hormone-sensitive GTPase of human platelets by 1-O-Alkyl-2-O-acetyl-sn-glyceryl-3-phosphocholine (platelet activating factor)

Авдонин, П. В.; Svitina-Ulitina, I.V.; Kulikov, V. I.

doi:10.1016/0006-291x(85)91803-0

Cited by 28 publications

(4 citation statements)

References 23 publications

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“…The initial observations concerning the involvement of Gproteins in PAF action were made in the early 1980s. It was found that synthetic PAF inhibited adenylate cyclase activity in the particulate fraction ofplatelets [48,49] and stimulated GTPase activity as well [49][50][51][52][53]. In an effort to elucidate the identity and properties of G-protein(s) involved in the activation of platelets, involving proteolytic digestion of the G-protein and subsequent two-dimensional electrophoresis, it was concluded that in platelets a single pertussis toxin-sensitive, ac4-containing G-protein was invoved in the regulation of both adenylate cyclase and phospholipase C. In rabbit platelets, PAF receptor stimulation increased GTPase activity [51,52] and this stimulatory effect of PAF on GTPase activity was attenuated in cells pretreated with phorbol ester, dibutyryl cyclic AMP, and by PAF-induced desensitization [51].…”

Section: Linkage With Guanine Nucleotide Regulatory Proteinsmentioning

confidence: 99%

Platelet-activating factor: receptors and signal transduction

Chao

Olson

1993

Biochemical Journal

430

270

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During the past two decades, studies describing the chemistry and biology of PAF have been extensive. This potent phosphoacylglycerol exhibits a wide variety of physiological and pathophysiological effects in various cells and tissues. PAF acts, through specific receptors and a variety of signal transduction systems, to elicit diverse biochemical responses. Several important future directions can be enumerated for the characterization of PAF receptors and their attendant signalling mechanisms. The recent cloning and sequence analysis of the gene for the PAF receptor will allow a number of important experimental approaches for characterizing the structure and analysing the function of the various domains of the receptor. Using molecular genetic and immunological technologies, questions relating to whether there is receptor heterogeneity, the precise mechanism(s) for the regulation of the PAF receptor, and the molecular details of the signalling mechanisms in which the PAF receptor is involved can be explored. Another area of major significance is the examination of the relationship between the signalling response(s) evoked by PAF binding to its receptor and signalling mechanisms activated by a myriad of other mediators, cytokines and growth factors. A very exciting recent development in which PAF receptors undoubtedly play a role is in the regulation of the function of various cellular adhesion molecules. Finally, there remain many incompletely characterized physiological and pathophysiological situations in which PAF and its receptor play a crucial signalling role. Our laboratory has been active in the elucidation of several tissue responses in which PAF exhibits major autocoid signalling responses, e.g. hepatic injury and inflammation, acute and chronic pancreatitis, and cerebral stimulation and/or trauma. As new experimental strategies are developed for characterizing the fine structure of the molecular mechanisms involved in tissue injury and inflammation, the essential role of PAF as a primary signalling molecule will be affirmed. Doubtless the next 20 years of experimental activity will be even more interesting and productive than the past two decades.

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Section: Linkage With Guanine Nucleotide Regulatory Proteinsmentioning

confidence: 99%

Platelet-activating factor: receptors and signal transduction

Chao

Olson

1993

Biochemical Journal

430

270

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“…PAF also stimulates GTPase activity in human platelets or their isolated membranes (Avdonin et al, 1985). Many actions of PAF in other cell types require extracellular calcium and are inhibited by calcium antagonists (O'Flaherty, 1987).…”

Section: Discussionmentioning

confidence: 99%

Effect of platelet-activating factor (PAF) on human spermatozoa-oocyte interactions

Angle¹,

Tom²,

Jarvi³

et al. 1993

Reproduction

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The effect of exogenous platelet-activating factor (PAF) on human spermatozoa was examined by monitoring acrosomal status and hamster oocyte penetration. Induction of the acrosome response by PAF was dose, and time, dependent and required capacitated spermatozoa. Addition of 10(-14) mol PAF l-1 enhanced the acrosome reaction eightfold compared with controls treated with human serum albumin (HSA). Similar concentrations of lyso-PAF failed to induce acrosomal loss and preincubation of spermatozoa with CV3988, an inhibitor of PAF, prevented PAF induction of the acrosome reaction. PAF significantly increased the number of zona-free hamster oocytes penetrated compared with controls (9.8 +/- 0.5 of 25 oocytes were penetrated by control spermatozoa compared with 23.3 +/- 0.8 out of 25 oocytes penetrated after incubation of spermatozoa with 10(-14) mol PAF l-1; 93% of all oocytes were penetrated by at least one spermatozoon following incubation with PAF), and also increased the number of decondensed spermatozoa found per egg during the sperm penetration assay (from 1.7 +/- 0.3 spermatozoa/egg with control spermatozoa to 3.3 +/- 0.5 spermatozoa/egg with PAF-treated spermatozoa). PAF-induced increases in acrosome reaction and sperm penetration assay values were similar to effects obtained with human follicular fluid and were calcium dependent. Induction of the acrosome reaction by physiological concentrations of PAF appeared to be morphologically similar to the response induced by follicular fluid as assessed by electron microscopy.

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“…The exact sequence of events and biochemical mechanism in this process are still unknown, but experimental evidence suggests that the activated PAF receptor might interact with a GTPbinding protein (122)(123)(124)(125)(126) in the membrane.…”

Section: Biochemical Mode Of Action Of Pafmentioning

confidence: 99%