Apocrine glands in the eyelid of primates contribute to the ocular host defense

Apocrine glands of Moll are regular components of primate eyelids.
We studied the distribution and localization of these glands in
three different primate species, the common marmoset, the rhesus
monkey, and the hamadryas baboon. In addition, we tested the
primate glands of Moll with antibodies against antimicrobial
proteins, cytoskeletal proteins and the androgen receptor. The
glands of Moll differ in abundance and distribution in different
monkeys. In the common marmoset, a representative of the New World
monkeys, Platyrrhini, the apocrine glands are frequently found at
the lid margin and in the overlying epidermis of the lid. In the
rhesus monkey and the hamadryas baboon, representatives of Old
World monkeys, Catarrhini, apocrine glands are rarer and located
predominantly at the margin of the lid. The immunohistochemical
analysis indicates the presence of a variety of antimicrobial
proteins, e. g. lysozyme, beta-defensin-2, adrenomedullin,
lactoferrin, and IgA, in these glands. Interestingly, there are
basically no androgen receptors in the nuclei of apocrine glands at
the lid margin in all three monkey species. In the common marmoset,
however, androgen receptors are found in apocrine glands of the
overlying epidermis of the lid. We speculate that the glands of
Moll are derived from apocrine glands as found in the skin of the
entire body in New World monkeys which developed at the lid margins
of higher primates and humans into specialized glands secreting
agents of host defense in the eye. Copyright (C) 2004 S. Karger AG,
Basel.