Summary
With two different antisera to human prolactin (hPRL), the ultrastructural localization
of PRL-like material in the bee brain is examined by means of the protein-A-gold method
at the electron microscopical level. Labelling is found in electron-dense granules
of medium size (150-200 nm in diameter) for the first time in insects. Such granules
are distributed in the cytoplasm of the neurosecretory cells, their axons and their
axon-terminals. The electron-dense granule is one criterion for identifying a neurosecretory
cell. In the honeybee, hPRL-like material may serve as an old neurohormone with respect
to its evolution.
Key words
Comparative Endocrinology - Honeybee - Neurosecretory Granula - Prolactin
