Effects of prolactin on the kidney of a teleostean fish: Transmission electron microscopic observations

Abstract

Mammalian prolactin (PRL) was previously found to be toxic to the dwarf gourami, Colisa lalia. In an effort to identify the cause of the PRL toxicity, kidneys of fish treated with the hormone were examined by transmission electron microscopy. At the ultrastructural level many degenerating cells, characterized by nuclear fragmentation, cytoplasmic dissolution, and pyknosis, were seen in the renal tubules. A variety of profiles of crystalline bodies were present in the interstitial tissue. Neither crystalline bodies nor degenerating cells were seen in kidneys from control animals. These findings provide a clear indication that the kidney is at least one of the primary sites of the PRL toxic effect.