Prostaglandin production in cultured cerebral microvascular smooth
muscle is serum-dependent.
Rich, Gretchen, Elizabeth J. Yoder, Laura Prokuski, and Steven A.
Moore.
Department of Pathology, The University of Iowa, Iowa City, IA
52242-1181
APStracts 2:0411C, 1995.
To expand the understanding of cerebrovascular eicosanoid metabolism,
the ability of smooth muscle isolated from murine cerebral
microvessels to produce prostaglandins (PG) was studied in vitro.
Cultures from SJL and BALB/c mice produced primarily PGE2 and PGI2 in
response to exogenous arachidonate and calcium ionophore, as well as
the agonists acetylcholine and epinephrine. Subconfluent smooth
muscle cultures demonstrated a 2- to 3-fold increased capacity to
produce PG compared to confluent cultures. In contrast, serum
deprivation of smooth muscle caused an 80-90% diminution in both PGE2
and PGI2 production but had no effect on PG release in
cerebromicrovascular endothelium. Reintroduction of serum to smooth
muscle restored PG production within 6 h and the restoration was
inhibited by 1 M dexamethasone. Message for both PGH synthase (PGHS)
-1 and -2 was detectable in smooth muscle grown in the presence of
serum, but PGHS-2 message was not present in serum-deprived cultures.
Furthermore, readdition of serum induced a massive increase in PGHS-2
mRNA with only a small increase in PGHS-1 message. The serum
induction of PGHS-2 was corroborated by immunohistochemistry and
Western blotting. Thus, cerebromicrovascular smooth muscle may
contribute significantly to the formation of PG under circumstances
likely to be present during CNS pathologies. The induction of PGHS,
particularly PGHS-2, may play a key role in this process.
Received 12 June 1995; accepted in final form 10 November 1995.
APS Manuscript Number C338-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95