The XXXX pituitary expresses an ovoinhibitor-like protein in subpopulations of some, but not all, hormone-producing cell types.

@entity172 @entity55682 @entity17548 @entity1420 @entity1573 @entity563 @entity35
Ovoinhibitor is a @entity563 protease-inhibiting protein that was originally purified from egg whites. It is secreted by the oviduct under the control of @entity172 and @entity1420 and it specifically inhibits @entity563 proteinases such as trypsin and chymotrypsin. During recent attempts to raise monoclonal antibodies (Mabs) against @entity1573 bursa of Fabricius proteins, one Mab was produced that specifically recognized @entity1573 ovoinhibitor. This was the first demonstration of ovoinhibitor in an avian immune organ. We presently report on the expression of an ovoinhibitor-like molecule by the pituitary of the @entity1573 as revealed by immunocytochemistry and RT-PCR. Immunofluorescent dual staining experiments using the mouse anti-ovoinhibitor Mab in conjunction with polyclonal antibodies against various hypophysial hormones revealed partial co-localization of an ovoinhibitor-like molecule with @entity17548 ( @entity17548 ), luteinizing hormone (LH), and @entity55682 ( @entity55682 ), in a subset of the respective hormone producing cells. By contrast, no co-localization with prolactin (PRL) could be reliably demonstrated. RT-PCR of hypophysial mRNA using ovoinhibitor gene-specific primers yielded an amplicon that was 20% shorter than predicted on the basis of the published ovoinhibitor sequence. Sequencing revealed that of the represented exons only the central portion was expressed in the pituitary and that both 5' and 3' ends of each exon had been truncated. While expression of ovalbumin-like @entity563 protease inhibitors (serpins) has been previously reported in the @entity35 pituitary, to our knowledge, this is the first report of a Kazal-type @entity563 protease inhibitor in the vertebrate neuroendocrine system.
