Kivonat:
The presence of pituitary adenylate cyclase activating
polypeptide (PACAP) was previously demonstrated in the anterior
pituitary by radioimmunoassay, immunohistochemistry, and reverse
transcript-polymerase chain reaction (RT-PCR). With the use of
cell immunoblot assay (CIBA), when the pituitary cells were
cultured on nitrocellulose membrane, the release of PACAP by
individual anterior pituitary cells was observed. The released
peptide, trapped by the nitrocellulose membrane forming a blot
around the cells, was demonstrated by immunocytochemistry.
Double labeling revealed that a part of PACAP-immunoreactive
cells can release LH as well. With the use of sandwich enzyme
immunoassay (S-EIA), it was found that the concentration of
PACAP in the anterior pituitaries is 10(-10) M. In cell culture
in a similar concentration, PACAP stimulated the LH release from
female gonadotropes, but did not influence it from male ones.
The stimulated release of LH was indicated by the enhancement in
the diameter of LH blots compared to the untreated control
cultures. We concluded that PACAP may be released from the
anterior pituitary cells in a concentration which would be able
to influence LH release not only in vitro but under in vivo
conditions as well. The effect of PACAP on LH release was
different in female and male pituitary cultures.