Atrial Natriuretic Peptides in Antarctic Fish
Maria Angela Masini\ Maddalena Sturla\ Eva Pisano\ Philippe Koubbi2,
Rosella Coradeghinil, and Bianca Maria Uva l
IIstituto di Anatomia Comparata, Universita di Genova, 5 viale Benedetto XV,
16132 Genova, Italia; 2Universite du Littorel, Station Marine de Wimereux, France
Introduction
Atrial natriuretic factors (ANFs) belong to a family of peptides originally
described in mammalian heart. Beside ANPs, two other different types of
natriuretic peptides with high sequence similarity have been identified, Btype natriuretic peptide (BNP) in the heart of chicken and mammals, and Ctype natriuretic peptide (CNP) in the brain [1]. Their physiological and
pharmacological effects have been extensively studied, their structure is
known [2,3], their primary effects in mammals are natriuretic, diuretic and
vasorelaxant [4,5]. ANFs are also present in nonmammalian vertebrates
including birds [6], reptiles [7,8], amphibians [1,9,10], jawed [1,7,11,12]
and jawless fishes [13]. Moreover, there are specific binding sites for ANP
in several vertebrates' tissues. Extracts from fish heart stimulate ion
excretion in the trout [14] and are vasodepressor in the quail [15]. In
addition, rat ANP stimulates chloride secretion from the killifish opercular
membrane in vitro [16]. Together these data indicate that ANFs regulate
body water, electrolyte balance and cardiovascular dynamics in vertebrates.
To inhabit deep cold water, Antarctic and subAntarctic fish have developed
remarkable cardiovascular adaptations like reduction of the number of red
blood cells: this adaptation is extreme in Channichthyidae which have
erythrocyte-free blood. To compensate for the lack of hemic pigments, the
icefish possess a hypertrophic heart [17,18] that generates a high cardiac
output [19]; the blood volume is also very large [20]. ANF-like peptides are
likely to be involved in the regulation of blood volume, cardiovascular
activity, and ion-fluid balance in Antarctic teleosts.
The present paper addresses in sequence the general characteristics of
atrial natriuretic peptides in terms of their molecular structures, localization
of ANP-like immunoreactivity and distribution of ANP binding sites in
adults, and finally immunoreactivity in a larval stage.
Characterization of ANP Molecules in Teleosts
Immunocytochemical studies using antisera against rat ANP (rANP),
human ANP (hANP) or porcine ANP have revealed the presence of irG. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998
Maria Angela Masini\ Maddalena Sturla\ Eva Pisano\ Philippe Koubbi2,
Rosella Coradeghinil, and Bianca Maria Uva l
IIstituto di Anatomia Comparata, Universita di Genova, 5 viale Benedetto XV,
16132 Genova, Italia; 2Universite du Littorel, Station Marine de Wimereux, France
Introduction
Atrial natriuretic factors (ANFs) belong to a family of peptides originally
described in mammalian heart. Beside ANPs, two other different types of
natriuretic peptides with high sequence similarity have been identified, Btype natriuretic peptide (BNP) in the heart of chicken and mammals, and Ctype natriuretic peptide (CNP) in the brain [1]. Their physiological and
pharmacological effects have been extensively studied, their structure is
known [2,3], their primary effects in mammals are natriuretic, diuretic and
vasorelaxant [4,5]. ANFs are also present in nonmammalian vertebrates
including birds [6], reptiles [7,8], amphibians [1,9,10], jawed [1,7,11,12]
and jawless fishes [13]. Moreover, there are specific binding sites for ANP
in several vertebrates' tissues. Extracts from fish heart stimulate ion
excretion in the trout [14] and are vasodepressor in the quail [15]. In
addition, rat ANP stimulates chloride secretion from the killifish opercular
membrane in vitro [16]. Together these data indicate that ANFs regulate
body water, electrolyte balance and cardiovascular dynamics in vertebrates.
To inhabit deep cold water, Antarctic and subAntarctic fish have developed
remarkable cardiovascular adaptations like reduction of the number of red
blood cells: this adaptation is extreme in Channichthyidae which have
erythrocyte-free blood. To compensate for the lack of hemic pigments, the
icefish possess a hypertrophic heart [17,18] that generates a high cardiac
output [19]; the blood volume is also very large [20]. ANF-like peptides are
likely to be involved in the regulation of blood volume, cardiovascular
activity, and ion-fluid balance in Antarctic teleosts.
The present paper addresses in sequence the general characteristics of
atrial natriuretic peptides in terms of their molecular structures, localization
of ANP-like immunoreactivity and distribution of ANP binding sites in
adults, and finally immunoreactivity in a larval stage.
Characterization of ANP Molecules in Teleosts
Immunocytochemical studies using antisera against rat ANP (rANP),
human ANP (hANP) or porcine ANP have revealed the presence of irG. di Prisco, E. Pisano, A. Clarke (Eds)
Fishes of Antarctica. A biological overview
© Springer-Verlag Italia 1998