Preprint volume - SIBM

Pre-print Volume - Posters
VARIOUS TOPICS
present in the epithelium of medium and posterior gut and in the rectal valve. In the
same intestinal regions the apical border of epithelium was covered by a strong positive
stripe. Moreover the liver showed an increased number of positive cells. An intense IR
was observed in all pituitary cells. The IR appeared also in the renal proximal tubules
around the lumen. In the larvae fixed 1 h following LPS treatment the IR pattern was
comparable to that described for larvae immediately after treatment fixed, even if the
IR disappeared in the pronephros tubules and was less intense in the hepatocytes.
Conclusions – Our results showed a different IR pattern in treated and untreated
larvae. Indeed, we observed an IR induction of HSP70 in a greater number of cells and
in some tissues after treatment with LPS, particularly in a short time (1 h).
Most of the evidences about how the generalized stress response and HSPs expression
may be related comes from mammals studies. Hypophysectomized rats did not show
the HSP gene expression in response to stress and addition of ACTH to those rats
induced HSP expression in the adrenals glands. These data support the idea of a
functional relationship between HSP expression and hypothalamus-pituitary-adrenal
axis (Iwama et al., 1999). Some data are available for fish, showing the increase in
HSPs (60, 70, 90 kDa) in various tissues of different species subjected to stressors,
such as heat shock, environmental contaminants and bacteria. Liver, kidney and gills
seem to be the most sensible tissues to HSPs response (see Iwama et al., 1999). In the
sea bass larvae the involved organs are liver, pronephros tubules, gut, skin, gills and
hypophysis. This suggest that the HSP response involves a greater number of organs in
larvae than in adults fish.
The IR to HSP70 in 24 day-old larvae LPS treated are very similar to those described
previously for ACTH-IR in the same larval stages (Mola et al., 2005). This may
indicate that HSP70 also belongs to the pool of molecules involved in the early
immune responses of sea bass larval stages.
References
IWAMA G.K., VIJAYAN M.M., FORSYTH R.B., ACKERMAN P.A. (1999) – Heat Shock Proteins
and physiological stress in fish. Amer. Zool., 39: 901-909.
MOLA L., GAMBARELLI A., PEDERZOLI A. (2009) – Immunolocalization of corticotropin
releasing factor (CRF) and corticotropin releasing factor receptor (CRF-R2) in the developing
gut of the sea bass (Dicentrarchus labrax L.). Acta Histochem., doi:
10.1016/jacthis.2009.11.002.
MOLA L., GAMBARELLI A., PEDERZOLI A., OTTAVIANI E. (2005) – ACTH response to LPS
stressor in the first stages of the development of the fish Dicentrarchus labrax (L.). Gen. Comp.
Endocrinol., 143: 99-103.
PEDERZOLI A., CONTE A., TAGLIAZUCCHI D., GAMBARELLI A., MOLA L. (2007) –
Occurrence of two NOS isoforms in the developing gut of Dicentrarchus labrax (L.). Histhol.
Histopathol., 22: 1057-1064.
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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