Compared with serum the aqueous humor of the eye is high in ascorbic acid. The administation of ascorbic acid appears to have a transient hypotonic effect on intraocular pressure in normal eyes. Its effect on glaucomatous eyes is not as well defined particularly in the case of the rabbit. In this communication we shown the ocular hypotensive effal (+/+) or have hereditary glaucoma (bu/bu). We also show that the transport of ascorbate from the serum to the aqueous is much slower in buphthalamic rabbits than in normal controls. Osmolarity is suggested as a possible hypotensive mechanism and a differential fluid transport rate between the blood and the aqueous for the different genotypes is suggested as a possible mechanism for the difference in duration.

Animals↗

PubMedDate not supplied

Ascorbate concentration in tissues from normal and buphthalmic rabbits.

Previous studies show a progressive lowering of ascorbate concentration in the aqueous humor from rabbits with hereditary buphthalmus, depending on the severity of the buphthalmus. In this study, the ascorbate concentration of different tissues from age-matched adult buphthalmic and control rabbits were analyzed to determine whether a defect of ascorbate transport occurs in a variety of tissues from rabbits with hereditary buphthalmus. Our results showed that ascorbate changes were observed only in ocular tissues. The lowering of ascorbate concentration occurs only in lens and cornea, which depend on the aqueous humor to deliver ascorbate from the blood. The tissues that derive ascorbate directly from the blood, such as the ciliary body-iris and retina of buphthalmic eyes, have normal ascorbate concentration. It has been postulated that ascorbate is oxidized in the ciliary body-iris to facilitate its transport across the epithelium. A defect in the buphthalmic eyes to oxidize ascorbate could be the primary cause of lowering ascorbate concentration in the aqueous humor.

Adrenal Glands↗

PubMedDate not supplied

Fibrinogen concentration in the aqueous humor of buphthalmic rabbits.

Fibrinogen concentration in the aqueous humor of buphthalmic rabbits, AXBU/J, and those of the normal parent strain AX/J are 0.36 +/- 0.14 and 0.08 +/- 0.01 mg/ml, respectively. There was no detectable fibrinogen in the aqueous humor of normal inbred strain III/J rabbits. Among the buphthalmic rabbits, elevated fibrinogen concentration in the aqueous humor was observed in two month old prodromal rabbits, indicating a small leakage of fibrinogen into the anterior chamber before the development of buphthalmia. Protein concentration in the aqueous humor was close to normal, in spite of an elevated level of fibrinogen in the young buphthalmic rabbits. Severe protein leakage was seen in only some of the old buphthalmic rabbits.

Age Factors↗

PubMedDate not supplied

Detection of uric acid in aqueous humor by high pressure liquid chromatography.

The uric acid peak among the compounds in aqueous humor separated by high pressure liquid chromatography was identified by its retention time, the UV absorbance characteristics, and the effect of uricase. The uric acid concentration in the aqueous humor of normal monkey, human eyes with cataract, and human eyes with glaucoma are less than 0.05, 1.7 +/- 0.3, and 3.8 +/- 0.4 respectively. The significance of high uric acid concentration in glaucoma is discussed.

Animals↗