Related Experiment Videos
Two distinct receptors for ATP can be distinguished in Swiss 3T6 mouse fibroblasts by their desensitization
F A Gonzalez1, E Bonapace, I Belzer
1Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853.
Abstract:
The stimulation of calcium efflux from Swiss 3T6 mouse fibroblasts by extracellular ATP was studied. It was found that the cells could be desensitized to ATP by a previous exposure to the nucleotide, lending support to the theory that this is a receptor mediated process. Another ATP-receptor mediated process in Swiss 3T6 cells, that is also subject to desensitization, causes the permeabilization of the plasma membrane to nucleotides and other normally impermeant compounds [Gonzalez et al., J. Cell. Physiol. 139:109 (1989)]. Here we demonstrate that selective desensitization of the ATP-dependent calcium mobilization pathway can be achieved without affecting ATP-induced permeabilization. Data are presented in support of the existence of multiple ATP-receptors (purinoceptors) in Swiss 3T6 cells.
Insights
Extracellular adenosine triphosphate (ATP) triggers calcium efflux in mouse fibroblasts, suggesting a receptor-mediated process. Researchers selectively desensitized this calcium pathway, indicating multiple ATP receptors on cells.
Area of Science:
- Cell biology
- Biochemistry
- Molecular pharmacology
Background:
- Extracellular adenosine triphosphate (ATP) is known to regulate cellular processes in various cell types.
- ATP-induced responses in Swiss 3T6 mouse fibroblasts, such as calcium efflux and plasma membrane permeabilization, are mediated by purinergic receptors.
- These ATP-mediated processes are known to be subject to desensitization upon prolonged exposure to ATP.
Purpose of the Study:
- To investigate the desensitization characteristics of ATP-stimulated calcium efflux in Swiss 3T6 fibroblasts.
- To determine if the calcium mobilization pathway can be selectively desensitized independently of ATP-induced plasma membrane permeabilization.
- To provide evidence for the existence of multiple ATP receptors (purinoceptors) in Swiss 3T6 cells.
Main Methods:
- Utilized Swiss 3T6 mouse fibroblasts for experimental studies.
- Applied extracellular adenosine triphosphate (ATP) to stimulate cellular responses.
- Monitored calcium efflux and plasma membrane permeabilization.
- Investigated desensitization by pre-exposing cells to ATP.
Main Results:
- Extracellular ATP stimulates calcium efflux from Swiss 3T6 fibroblasts.
- Cells exhibited desensitization to ATP-induced calcium efflux after prior exposure to the nucleotide.
- Selective desensitization of the calcium mobilization pathway was achieved without impacting ATP-induced plasma membrane permeabilization.
- Data support the presence of multiple distinct ATP receptors on Swiss 3T6 cells.
Conclusions:
- The desensitization of ATP-induced calcium efflux supports a receptor-mediated mechanism.
- Swiss 3T6 cells possess at least two distinct purinoceptors mediating different cellular responses.
- These findings highlight the complexity of purinergic signaling and receptor heterogeneity in fibroblasts.