Medical/biological study (experimental study)

Upregulation of specific mRNA levels in rat brain after cell phone exposure med./bio.

By: Yan JG, Agresti M, Zhang LL, Yan Y, Matloub HS

Published in: Electromagn Biol Med 2008; 27 (2): 147-154

Aim of study (acc. to editor)

To check the hypothesis that cell phone irradiation can cause cellular damage to the rat brain leading to increased mRNA transcription of injury-associated proteins.

Background/further details

Fourteen 3-month-old male adult rats, weighing 250 to 350 g, were used.

Endpoint

molecular biosynthesis: mRNA synthesis of several injury-associated proteins

Exposure

- microwaves
- CDMA
- mobile communications
- analog mobile phone
- digital mobile phone
- PCS

Exposure	Parameters
Exposure 1: 1.9 GHz Exposure duration: repeated daily exposure, 2 x 3 h/day, for 18 weeks	SAR: 1.8 W/kg (AMPS) SAR: 0.9 W/kg (CELL) SAR: 1.18 W/kg (PCS)

Exposure 1

Main characteristics

Frequency	1.9 GHz
Type	electromagnetic field
Exposure duration	repeated daily exposure, 2 x 3 h/day, for 18 weeks

Modulation

Modulation type	unspecified

Exposure setup

Exposure source	cellular phone
Distance between exposed object and exposure source	1 cm
Chamber	The rats were placed in holding units consisting of ventilated 5.1 cm x 15.2 cm PVC tubes fitted with 0.59-liter clear plastic bottle tops on one end and common 7.6-cm bolts with nuts at the other end. As the rats grew larger, new units were made using 8.9-cm PVC tubes, 1-liter bottles, and 10.2-cm bolts with nuts.
Setup	Each cell phone was positioned 1 cm from the head of the rats, at equal distances between two rats in holding chambers.
Sham exposure	A sham exposure was conducted.
Additional info	Rats were exposed for 3 hours, followed by a 30-minute rest period outside of the tubes and a second exposure for 3 more hours per day.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	1.8 W/kg	-	measured	-	AMPS
SAR	0.9 W/kg	-	measured	-	CELL
SAR	1.18 W/kg	-	measured	-	PCS

Additional parameter details

The four cell phones used in the study had a PCS CDMA frequency band of 1.9 GHz (800 MHz digital and 800 MHz analog) and three different modes (AMPS mode, CELL mode, and PCS mode) that can be used based on signal reception, antenna use, and other factors associated with reception of different types of RF signals. The actual exposure is not specified in the article.

Measurement and calculation details

The SAR was measured at a distance of 2.2 cm.

Exposed system:

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: mRNA synthesis of several injury-associated proteins: calcium-ATPase, Neural Cell Adhesion Molecule, Neural Growth Factor, and Vascular Endothelial Growth Factor (reverse transcriptase polymerase chain reaction)
temperature of the face surface nearest the phone and rectal temperature at the end of exposure (thermometer)

Investigated system:

DNA/RNA

Investigated organ system:

brain/CNS

Time of investigation:

after exposure

Main outcome of study (acc. to author)

A statistically significant mRNA up-regulation of all investigated injury-associated proteins in the brains of rats exposed to cell phone irradiation was found. The differences in temperature measured were not statistically sinificant.
The authors conclude that relative chronic exposure to cell phone microwave irradiation may result in cumulative injuries that could eventually lead to clinically significant neurological damage.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

not stated/no funding

Maskey D et al. (2014): Immunohistochemical localization of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in the superior olivary complex of mice after radiofrequency exposure
Yan JG et al. (2009): Qualitative Effect on mRNAs of Injury-Associated Proteins by Cell Phone Like Radiation in Rat Facial Nerves
Huang TQ et al. (2008): Molecular responses of Jurkat T-cells to 1763 MHz radiofrequency radiation
Buttiglione M et al. (2007): Radiofrequency radiation (900 MHz) induces Egr-1 gene expression and affects cell-cycle control in human neuroblastoma cells
Zhao TY et al. (2007): Exposure to cell phone radiation up-regulates apoptosis genes in primary cultures of neurons and astrocytes
Whitehead TD et al. (2006): Gene expression does not change significantly in C3H 10T(1/2) cells after exposure to 847.74 CDMA or 835.62 FDMA radiofrequency radiation
Chauhan V et al. (2006): Gene Expression Analysis of a Human Lymphoblastoma Cell Line Exposed In Vitro to an Intermittent 1.9 GHz Pulse-Modulated Radiofrequency Field
Nikolova T et al. (2005): Electromagnetic fields affect transcript levels of apoptosis-related genes in embryonic stem cell-derived neural progenitor cells
Whitehead TD et al. (2005): Expression of the proto-oncogene Fos after exposure to radiofrequency radiation relevant to wireless communications
Czyz J et al. (2004): High frequency electromagnetic fields (GSM signals) affect gene expression levels in tumor suppressor p53-deficient embryonic stem cells
Goswami PC et al. (1999): Proto-oncogene mRNA levels and activities of multiple transcription factors in C3H 10T 1/2 murine embryonic fibroblasts exposed to 835.62 and 847.74 MHz cellular phone communication frequency radiation
Morrissey JJ et al. (1999): IRIDIUM exposure increases c-fos expression in the mouse brain only at levels which likely result in tissue heating