Pituitary adenylate cyclase-activating polypeptide (PACAP): a regulator of the innate and acquired immune functions in juvenile fish.
To date, published in-vivo studies on the action of the PACAP in fish are few and these are concerned with reproduction, brain development and feeding behavior. Recently, we demonstrated for the first time that PACAP, apart from its neuroendocrine role, influences immune functions in fish larvae. In this work, we have evaluated the effects of recombinant Clarias gariepinus PACAP administration by intraperitoneal injection on important immune parameters in juvenile fish. We observed that a single injection of the recombinant peptide (0.1 microg per g of body weight) was able to increase the nitric oxide synthase-derived metabolites (NOS) and total immunoglobulin M (IgM) concentration in serum of juvenile catfish C. gariepinus and tilapia Orechromis niloticus respectively, after 24 h of its administration. In addition, our results showed that recombinant PACAP increases IgM, NOS and lysozyme in serum correlated with its ability to enhance growth performance in juvenile fish. Finally, the PACAP mRNA expression and PACAP immunoreactivity detected in peripheral blood leucocytes from juvenile catfish suggest a direct autocrine or/and paracrine mechanism of regulation of this peptide to mediate immune functions in fish.
Aquatic Biotechnology Department, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, P.O. Box 6162, Havana 10600, Cuba.
Juana Maria
JM
Lugo
Yamila
Y
Carpio
Aymé
A
Oliva
Antonio
A
Morales
Mario Pablo
MP
Estrada
D000818:Animals; D001835:Body Weight; D002397:Catfishes / Q000097:blood / Q000254:growth & development / Q000276:immunology*; D023681:Cichlids / Q000276:immunology; D005786:Gene Expression Regulation / Q000187:drug effects; D006128:Growth / Q000187:drug effects; D007107:Immune System / Q000187:drug effects*; D007113:Immunity, Innate / Q000187:drug effects*; D007075:Immunoglobulin M / Q000097:blood; D007962:Leukocytes / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology; D009113:Muramidase / Q000097:blood; D019001:Nitric Oxide Synthase / Q000097:blood / Q000378:metabolism; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000494:pharmacology
D007075:Immunoglobulin M; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011994:Recombinant Proteins; D019001:Nitric Oxide Synthase; D009113:Muramidase