Osmotic pressure of the interstitial fluid obtained from neonatal chick eyes and its variation under light and dark adaptation.
In experiments by Yoneyama et al. (1985) a hypertonic perfusing solution was used to record the c-wave from the isolated chick retina. We investigated whether the chick retina was surrounded by such hypertonic liquids. The following results were found: the osmolarity of the subchoroidal humor was markedly higher than that of fluids from other areas of the eye; the relative difference in osmolarity between both sides of the retina was 110-170 mOsmol in the light-adapted condition, whereas it was about 270 mOsmol in the dark-adapted condition; and in the dark-adapted state the volume of the subchoroidal humor decreased about 40% but increased in osmolarity about 30-40%, whereas osmolarity of the subvitreous humor decreased about 15-20 mOsmol. Results suggest the presence of an inward-directed pump mechanism for water-soluble components in the retina in addition to the proposed outward-directed pump mechanism of the pigment epithelium. The inward-directed pump may be more active in the dark-adapted state.
D000222:Adaptation, Physiological; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001082:Aqueous Humor / Q000502:physiology; D001826:Body Fluids / Q000502:physiology*; D002645:Chickens; D003623:Dark Adaptation; D004596:Electroretinography; D005123:Eye / Q000378:metabolism*; D006982:Hypertonic Solutions; D007552:Isotonic Solutions; D008027:Light; D009997:Osmotic Pressure; D010477:Perfusion; D012160:Retina / Q000033:anatomy & histology / Q000502:physiology; D014822:Vitreous Body / Q000502:physiology
D006982:Hypertonic Solutions; D007552:Isotonic Solutions