An evaluation on the level of retinoids in the bovine pineal body.

Using high performance liquid chromatography, the level of retinoids was determined in the bovine pineal gland, retina, retinal pigment epithelium, cortical and subcortical brain tissues, skeletal muscle and the liver. Similar to the retina, the bovine pineal gland possesses levels of retinol and retinyl esters significantly higher than other brain tissues and muscle. These results are in agreement with the suggestion that the mammalian pineal gland and the retina may be of similar phylogenetic origin. However, unlike the retina, the bovine pineal gland does not possess any detectable level of retinal, the chromophore for visual pigments in the retina. This finding suggests that the bovine pineal gland does not possess rhodopsin nor the property of phototransduction which has been fully established in the retina and pineal glands of lower vertebrates.