Document Detail

Humoral phototransduction: light transportation in the blood, and possible biological effects.
MedLine Citation:
PMID:  18440721     Owner:  NLM     Status:  MEDLINE    
In our measurements plasma and, especially, the main plasma protein, albumin, exhibits a long-lasting light-induced luminescence, which should be capable of transporting light along the blood circulation. Moreover, albumin shows intense fluorescence, with emission at 337 nm, which is controlled by bilirubin. Furthermore, it is known that tryptophan decarboxylase, the last step of serotonin formation, is directly activated by light, with a maximum at 337 nm. As a hypothesis, we propose that light-induced luminescence of plasma components, such as albumin and free radicals, transports ambient light along the blood vessels. This emission could have photochemical and photobiological effects, e.g., photomodulation of enzymes. Albumin fluorescence emission could stimulate serotonin formation at 337 nm, modulated by bilirubin. Such mechanisms could be involved in the action of light therapy on serotonin formation, melatonin suppression and circadian rhythms, both in the pathophysiology of seasonal affective disorder and major depression, and in blood pressure regulation via photovasorelaxation. The proposed model can be called humoral phototransduction.
F Grass; S Kasper
Publication Detail:
Type:  Letter     Date:  2008-04-28
Journal Detail:
Title:  Medical hypotheses     Volume:  71     ISSN:  0306-9877     ISO Abbreviation:  Med. Hypotheses     Publication Date:  2008 Aug 
Date Detail:
Created Date:  2008-06-30     Completed Date:  2008-09-19     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  7505668     Medline TA:  Med Hypotheses     Country:  Scotland    
Other Details:
Languages:  eng     Pagination:  314-7     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Albumins / metabolism
Aromatic-L-Amino-Acid Decarboxylases / metabolism
Blood Pressure
Free Radicals
Hydrogen-Ion Concentration
Models, Biological
Models, Theoretical
Serotonin / metabolism
Time Factors
Vision, Ocular*
Reg. No./Substance:
0/Albumins; 0/Free Radicals; 50-67-9/Serotonin; EC Decarboxylases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Prior chronic nicotine impairs cued fear extinction but enhances contextual fear conditioning in rat...
Next Document:  James Watson tells the inconvenient truth: faces the consequences.