Radioimmunoassay of sheep alpha- and gamma-crystallins II. Organ specificity of lens crystallins

The α- and γ-crystallin content in sheep ocular tissues was assayed by radioimmunoassay.In the normal sheep eye, the amounts assayed in extralenticular tissue extracts were found to be close to the lower limit of sensitivity of the assays, 2 ng/ml. making the nature of the measured effects uncertain. The concentrations found, indicated a crystallin content of less than 0·05 parts per million wet weight tissue. This concentration is so low that it is considered unlikely that the crystallins are produced outside the lens.Freezing and thawing of the intact eye caused leakage of crystallins from the lens to the surrounding tissues. Because of the enormous concentration gradient of crystallins across the lens capsule, even minute damage to the capsule was shown to cause crystallin contamination of the surrounding tissues. One sheep with Peter's anomaly in one eye had increased amount of crystallins outside the lens in both eyes.