Catecholamines modulate differentially nonapeptide precursor mRNA expression in the preoptic area and ovary of the catfish Heteropneustes fossilis: An in vitro study.

In the catfish Heteropneustes fossilis, three nonapeptide hormone genes were identified in the brain preoptic area (POA) and ovary: a pro-vasotocin (pro-vt) and two isotocin gene paralogs viz., a novel pro-ita and conventional pro-itb. In the present study, the regulatory role of catecholamines [CA: dopamine (DA), noradrenaline (NA), adrenaline (AD)] on the expression of these genes were investigated in vitro.

Reproductive roles of the vasopressin/oxytocin neuropeptide family in teleost fishes.

The vertebrate nonapeptide families arginine vasopressin (AVP) and oxytocin (OXT) are considered to have evolved from a single vasopressin-like peptide present in invertebrates and termed arginine vasotocin in early vertebrate evolution. Unprecedented genome sequence availability has more recently allowed new insight into the evolution of nonapeptides and especially their receptor families in the context of whole genome duplications. In bony fish, nonapeptide homologues of AVP termed arginine vasotocin (Avp) and an OXT family peptide (Oxt) originally termed isotocin have been characterized.

Molecular cloning and characterisation of an isotocin paralogue ([V8] isotocin) in catfishes (superorder Ostariophysi): Origin traced likely to the fish-specific whole genome duplication.

The present study reports the molecular cloning of a previously uncharacterised neurohypophyseal nonapeptide precursor cDNA in two catfish species: Heteropneustes fossilis and Clarias batrachus. The deduced nonapeptide is CYISNCPVG ([V8] isotocin), which has not been reported in any vertebrate till date. Phylogenetic and conserved synteny analyses showed the gene to have originated from the isotocin precursor (pro-it) gene by fish-specific whole genome duplication (3R).

Molecular cloning and characterization of the gonadotropin subunits GPα, FSHβ, and LHβ genes in the stinging catfish Heteropneustes fossilis: phylogeny, seasonal expression and pituitary localization.

Gonadotropins are heterodimeric glycoproteins secreted by the pituitary, and consist of a common glycoprotein hormone alpha (GPα) and the function-specific follicle-stimulating hormone beta subunit (FSHβ) or luteinizing hormone beta subunit (LHβ). In the present study, the subunit protein genes were cloned and characterized from the pituitary of the catfish Heteropneustes fossilis. Full-length cDNAs of GPα, FSHβ, and LHβ are 511 base pairs (bp), 659 bp and 660 bp long, and encode 92, 108, and 112 aminoacids long mature proteins, respectively.

Molecular cloning, sequencing and tissue expression of vasotocin and isotocin precursor genes from Ostariophysian catfishes: phylogeny and evolutionary considerations in teleosts.

Basic and neutral neurohypophyseal (NH) nonapeptides have evolved from vasotocin (VT) by a gene duplication at the base of the gnathostome lineage. In teleosts, VT and IT are the basic and neutral peptides, respectively. In the present study, VT and IT precursor genes of Heteropneustes fossilis and Clarias batrachus (Siluriformes, Ostariophysi) were cloned and sequenced.

Melanins as biomarkers of ovarian follicular atresia in the catfish Heteropneustes fossilis: biochemical and histochemical characterization, seasonal variation and hormone effects.

Follicular atresia is a common feature of the vertebrate ovary that occurs at different stages of folliculogenesis and ovarian regression. It has physiological significance to maintain homeostasis and control fecundity, and ensure removal of post-ovulatory follicular remnants for preparing the ovary for the next cycle. Pigments appear late in the atretic process as indigestible waste formed out of the degradation of the oocytes, follicle wall and granulocytes.

Molecular cloning, sequencing and phylogeny of vasotocin receptor genes in the air-breathing catfish Heteropneustes fossilis with sex dimorphic and seasonal variations in tissue expression.

Vasotocin (VT) is the ortholog of vasopressin (VP) in non-mammalian vertebrates and is known for multiple functions. Teleost fishes have a complete repertoire of known VP/VT receptor subtypes (vasopressin type, VR): two V1A subtypes (V1Aa and V1Ab or V1a1 and V1a2) and five V2 subtypes (V2A1, V1A2, V2B1, V2B2 and V2C). Full-length cDNAs of v1a1, v1a2 and v2 (v2a1) with ORFs of 1,308, 1,137 and 1,527 bp, respectively, were cloned and characterized in the catfish Heteropneustes fossilis (Siluriformes, Ostariophysi).

Differential and reproductive stage-dependent regulation of vasotocin secretion by catecholamines in the catfish Heteropneustes fossilis.

Vasotocin (VT) is the basic nonapeptide hormone secreted by the neurohypophysis of non-mammalian vertebrates and is involved in the regulation of osmoregulation, metabolism, cardiovascular function, reproduction and behaviour. Among the reproductive function, VT is specifically implicated in final oocyte maturation, ovulation, oviposition/parturition in teleosts, amphibians, reptiles, and birds. The central catecholaminergic system is involved in the regulation of pituitary hormone secretion including gonadotropin, and mediates also changes in environmental photoperiod and temperature.

Risperidone ameliorates post-traumatic stress disorder-like symptoms in modified stress re-stress model.

The management for post-traumatic stress disorder (PTSD) involves chronic administration of drugs. We have modified the stress re-stress (SRS) model to study the effect of chronic administration of risperidone (RIS) after induction of PTSD in rats. On day-1 (D-1) rats underwent training session for elevated-plus maze (EPM) test.

Estrogen regulation of brain vasotocin secretion in the catfish Heteropneustes fossilis: an interaction with catecholaminergic system.

Vasotocin (VT) is a basic neurohypophysial nonapeptide in non-mammalian vertebrates and is involved in diverse functions like osmoregulation, reproduction, metabolism and behavior. In this study, we report that estradiol-17β (E(2)) regulates brain and plasma VT secretion through the involvement of the catecholaminergic (CA) system. To demonstrate this, E(2) level was altered through ovariectomy (OVX, 3 weeks) and replacement study with low and high E(2) doses (0.

Estradiol-17β modulates dose-dependently hypothalamic tyrosine hydroxylase activity inhibited by α-methylparatyrosine in the catfish Heteropneustes fossilis.

The brain is a target for organizational and activational effects of oestrogens synthesized de novo or transported from the peripheral organs. A neuroprotective role of oestrogens has been documented in a variety of vertebrates. In the present study in the catfish Heteropneustes fossilis, we have demonstrated that estradiol-17β (E(2)), the major circulating oestrogen at low dosages (0.

Risperidone in ultra low dose protects against stress in the rodent cold restraint model by modulating stress pathways.

The present investigation evaluates the anti-stress activity of risperidone (RIS) in the cold restraint stress (CRS) model and related stress pathways. Rats were pretreated with RIS (0.1 and 1.

Glutamate antagonism fails to reverse mitochondrial dysfunction in late phase of experimental neonatal asphyxia in rats.

Neonatal asphyxia is a primary contributor to neonatal mortality and neuro-developmental disorders. It progresses in two distinct phases, as initial primary process and latter as the secondary process. A dynamic relationship exists between excitotoxicity and mitochondrial dysfunction during the progression of asphyxic injury.

Molecular and functional characterization of catfish (Heteropneustes fossilis) aquaporin-1b: changes in expression during ovarian development and hormone-induced follicular maturation.

The oocytes of the freshwater catfish Heteropneustes fossilis hydrate during hormone-induced meiotic maturation. To investigate if this process may be mediated by aquaporins (AQPs), as it occurs in marine fish producing highly hydrated eggs, the cloning of ovarian AQPs in catfish was carried out. Using degenerate primers for conserved domains of the major intrinsic protein (MIP) family, and 5' and 3'end amplification procedures, a full-length cDNA encoding for an AQP1-like protein was isolated.

2-Hydroxyestradiol-17beta-induced oocyte maturation in catfish (Heteropneustes fossilis) involves protein kinase C and its interaction with protein phosphatases.

In vitro effects of phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, calphostin C (PKC inhibitor) and okadaic acid [OA, a protein phosphatase (PP; PP1 and PP2A) inhibitor] on 2-hydroxyestradiol-17beta (2-OHE(2))-induced oocyte maturation were investigated in the catfish Heteropneustes fossilis. Incubations of postvitellogenic follicles with PMA or OA alone did not induce oocyte maturation. However, co-incubations with 2-OHE(2) and PMA (0.