Research

Project Title:
The effect of pulsed radiofrequency electromagnetic fields on redox signalling and calcium homeostasis

Start Date:
January 2002

Expected Date of Completion:
June 2005

Cost:
£496,000

Principal Investigator:
Dr. Martin D Bootman

Contact Details:
The Babraham Institute
Laboratory of Molecular Signalling
Babraham
Cambridge
CB2 4AT
UK

Project Team:
Peter Lipp, The Babraham Institute, Babraham, Cambridge CB2 4AT
Rod O'Connor, The Babraham Institute, Babraham, Cambridge CB2 4AT

Expertise:

The Laboratory of Molecular Signalling at the Babraham Institute are interested in how cells use calcium to coordinate a diverse array of cellular activities, ranging from gene transcription to muscle contraction. The group uses sensitive fluorescent probes and confocal-laser scanning microscopy to explore the subcellular movement of calcium with high spatial and temporal resolution. The versatility of these techniques also permits the measurement of many other important cellular signals, such as the production of the free radical nitric oxide (NO) and the movement of proteins within cells. These methods are currently being applied by the Laboratory of Molecular Signalling to explore how calcium functions in non-electrically excitable cells, neurons and in some of the pathophysiological aspects associated with heart disease such as cardiac hypertrophy and arrhythmias.

Approach:

The Babraham group will use high-throughput screening technology, which is used by the pharmaceutical industry in drug discovery research. An automated cellular imaging system will be constructed that will allow the measurement of cellular fluorescence, while the cells are exposed to pulsed radiofrequency (RF) electromagnetic fields similar to those produced by mobile phones. This will permit the real-time observation of signalling events that may occur when cells are exposed to RF fields. Mammalian tissues will be used, including neurons, glia, endothelium and smooth muscle, to cover a representative range of cell types that would be exposed during mobile phone use. The automation of the high-throughput imaging technology will permit a large number of samples to be processed and will minimize the possibility of experimental bias. Sophisticated software algorithms will then be used to extract information from the data to determine whether and where any signalling events are occurring.

Potential Difficulties:

One of the key challenges of this project is to successfully combine the high-throughput cellular imaging equipment with the system that will expose the cells to the RF fields. The Babraham group will be working closely with engineers who specialize in the construction of such systems. To our knowledge, a marriage of high-throught put screening technology and RF exposure has not been attempted before. Once the system is in place the actual experiments should not be problematic.

Importance:

The calcium ion is a ubiquitous intracellular messenger. It controls a diverse array of cellular activities, ranging from gene transcription to muscle contraction. The spatial and temporal characteristics, as well as the amplitude, of cellular calcium signals determine their biological function. Alterations of their physiological calcium homeostasis or calcium signals can have profound and serious consequences for virtually all cell types.

Over the last twenty years, several studies have reported that RF exposure may produce changes in cellular calcium homeostasis. Although some of these findings have been replicated by independent laboratories, other groups have failed to reproduce these results. Even though the type of RF fields used in these studies is not the same as those produced by current mobile phone technology, there are still some suggestions that calcium might be influenced. Consequently, further experiments using sensitive, high-throughput assays will help elucidate the role of cellular calcium, if any, in the biological effects of mobile phones.

There is some recent evidence from human and animal studies suggesting that mobile phones may have an impact on the diffusible free radical, nitric oxide. Nitric oxide is an important signalling molecule involved in the physiology of headache, memory, vascular permeability and our immune response. Therefore, it is important to rule out the effect of mobile phones on nitric oxide signalling. In a novel series of experiments, we will use the newly developed fluorescent probes for nitric oxide with our high-throughput imaging system to assess the effect of RF exposure on NO.