The lens circulation.
The lens is the largest organ in the body that lacks a vasculature. The reason is simple: blood vessels scatter and absorb light while the physiological role of the lens is to be transparent so it can assist the cornea in focusing light on the retina. We hypothesize this lack of blood supply has led the lens to evolve an internal circulation of ions that is coupled to fluid movement, thus creating an internal micro-circulatory system, which makes up for the lack of vasculature. This review covers the membrane transport systems that are believed to generate and direct this internal circulatory system.
Mathias
Richard T
RT
Department of Physiology and Biophysics, State University of New York at Stony Brook, Stony Brook, New York, NY 11794-8661, USA. richard.mathias@sunysb.edu
Kistler
Joerg
J
Donaldson
Paul
P
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D020346:Aquaporins / Q000502:physiology; D001692:Biological Transport / Q000502:physiology*; D002386:Cataract / Q000503:physiopathology; D048429:Cell Size; D002712:Chlorides / Q000378:metabolism; D017629:Gap Junctions / Q000502:physiology; D006801:Humans; D007908:Lens, Crystalline / Q000098:blood supply / Q000166:cytology / Q000502:physiology*; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology
D000975:Antioxidants; D020346:Aquaporins; D002712:Chlorides; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase