Acceleration of the meckel syndrome by near-infrared light therapy
Abstract
Background/aims: Phototherapy using a narrow-band, near-infrared (NIR) light (using a light-emitting diode, LED) is being used to treat certain medical conditions. This narrow-band red light has been shown to stimulate cytochrome c oxidase (CCO) in mitochondria that would stimulate ATP production and has the ability to stimulate wound healing. LED treatment also decreases chemical-induced oxidative stress in tested systems. As renal cystic diseases are known to have evidence of oxidative stress with reduced antioxidant protection, we hypothesized that NIR light therapy might ameliorate the renal pathology in renal cystic disease. Methods: Wistar-Wpk/Wpk rats with Meckel syndrome (MKS) were treated with light therapy on days 10-18 at which time disease severity was evaluated. Wpk rats were either treated daily for 80 s with narrow-band red light (640-690 nm wavelength) or sham treated. At termination, renal and cerebral pathology was evaluated, and renal expression and activity of enzymes were assessed to evaluate oxidative stress. Blood was collected for blood urea nitrogen (BUN) determination, the left kidney frozen for biochemical evaluation, and the right kidney and head fixed for morphological evaluation. Results: There were no significant effects of LED treatment on body weight (BW) or total kidney weight in non-cystic rats. Total kidney weight was increased and anephric BW was decreased in cystic versus non-cystic controls. LED reduced BW and total kidney weight in cystic rats compared to non-light-treated cystic (control) rats. BUN was already increased almost 6-fold in cystic rats compared to control rats. BUN was further increased almost 2-fold with NIR treatment in both non-cystic and cystic rats compared to cystic and control rats. The hydrocephalus associated with Wpk/Wpk (ventricular volume expressed as total volume and as percent of anephric BW) was also more severe in NIR-treated cystic rats compared to the normal control rats. Renal glutathione peroxidase and catalase (CAT) were reduced in the cystic kidney while superoxide dismutase and CCO were increased. NIR increased CAT and CCO, marginally decreased glutathione S-transferase and slightly decreased glutathione reductase in cystic rats compared to the normal control rats. The detrimental effects of NIR may be related to reduced renal blood flow associated with progression of cystic pathology. Compression by cysts may not allow sufficient oxygen or nutrient supply necessary to support the increased oxidative phosphorylation-associated cellular activity, and the increased demand induced by NIR-increased CCO may have created further oxidative stress. Conclusion: LED phototherapy initiated after the onset of symptoms was detrimental to MKS-induced pathology. NIR stimulates CCO thereby increasing the kidney's need for oxygen. We hypothesize that cystic compression of the vasculature impairs oxygen availability and the enhanced CCO activity produces more radicals, which are not sufficiently detoxified by the increased CAT activity.
AI evidence extraction
Main findings
In cystic rats, near-infrared/red LED treatment (640–690 nm) reduced body weight and total kidney weight compared with sham-treated cystic rats, and BUN increased further (reported as almost 2-fold) with NIR treatment in both non-cystic and cystic rats. Hydrocephalus severity was reported as more severe in NIR-treated cystic rats, and the authors conclude that phototherapy initiated after symptom onset was detrimental to MKS-induced pathology.
Outcomes measured
- Body weight (BW)
- Total kidney weight
- Blood urea nitrogen (BUN)
- Hydrocephalus/ventricular volume
- Renal and cerebral pathology (morphological evaluation)
- Renal oxidative stress-related enzyme expression/activity (e.g., glutathione peroxidase, catalase, superoxide dismutase, cytochrome c oxidase, glutathione S-transferase, glutathione reductase)
Limitations
- Sample size not reported in the abstract
- Animal model (Wistar-Wpk/Wpk rats) limits direct generalization to humans
- Exposure described by wavelength and duration but not by irradiance/energy dose at tissue
- Treatment window limited to days 10–18; timing relative to disease course may affect results
View raw extracted JSON
{
"study_type": "animal",
"exposure": {
"band": "near-infrared",
"source": "LED phototherapy",
"frequency_mhz": null,
"sar_wkg": null,
"duration": "Daily for 80 s on days 10–18"
},
"population": "Wistar-Wpk/Wpk rats with Meckel syndrome (MKS) and non-cystic rats",
"sample_size": null,
"outcomes": [
"Body weight (BW)",
"Total kidney weight",
"Blood urea nitrogen (BUN)",
"Hydrocephalus/ventricular volume",
"Renal and cerebral pathology (morphological evaluation)",
"Renal oxidative stress-related enzyme expression/activity (e.g., glutathione peroxidase, catalase, superoxide dismutase, cytochrome c oxidase, glutathione S-transferase, glutathione reductase)"
],
"main_findings": "In cystic rats, near-infrared/red LED treatment (640–690 nm) reduced body weight and total kidney weight compared with sham-treated cystic rats, and BUN increased further (reported as almost 2-fold) with NIR treatment in both non-cystic and cystic rats. Hydrocephalus severity was reported as more severe in NIR-treated cystic rats, and the authors conclude that phototherapy initiated after symptom onset was detrimental to MKS-induced pathology.",
"effect_direction": "harm",
"limitations": [
"Sample size not reported in the abstract",
"Animal model (Wistar-Wpk/Wpk rats) limits direct generalization to humans",
"Exposure described by wavelength and duration but not by irradiance/energy dose at tissue",
"Treatment window limited to days 10–18; timing relative to disease course may affect results"
],
"evidence_strength": "low",
"confidence": 0.7399999999999999911182158029987476766109466552734375,
"peer_reviewed_likely": "yes",
"keywords": [
"near-infrared",
"red light",
"LED phototherapy",
"Meckel syndrome",
"renal cystic disease",
"Wistar-Wpk/Wpk rat",
"blood urea nitrogen",
"hydrocephalus",
"oxidative stress",
"cytochrome c oxidase",
"catalase"
],
"suggested_hubs": []
}
AI can be wrong. Always verify against the paper.
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