Effects of gonadotropin-releasing hormone (GnRH) analogs and sex steroids on growth hormone (GH) secretion and growth in common carp (Cyprinus carpio) and grass carp (Ctenopharyngodon idellus)

Lin, Haoran; Lu, Ming; Lin, Xinwei; Zhang, W.M.; Sun, Yuhan; Chen, L.X.

doi:10.1016/0044-8486(95)01012-2

Cited by 24 publications

(6 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The magnitude of these GH responses is comparable with, if not higher than, that of other known GH-releasing factors previously reported in common carp, e.g. gonadotropin-releasing hormone [43], thyrotropin-releasing hormone [44]and dopamine [45]. These results confirm that PACAP serves as a potent GH secretagogue in teleosts including cyprinids.…”

Section: Discussionsupporting

confidence: 75%

Regulation of Growth Hormone Release in Common Carp Pituitary Cells by Pituitary Adenylate Cyclase-Activating Polypeptide: Signal Transduction Involves cAMP- and Calcium-Dependent Mechanisms

et al. 2002

View full text Add to dashboard Cite

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a member of the glucagon/secretin peptide family and its molecular structure is highly conserved among vertebrates. In this study, the role of PACAP in regulating growth hormone (GH) secretion in fish was examined in vitro using common carp pituitary cells under column perifusion. A dose-dependent increase in GH release was observed after exposing pituitary cells to increasing doses of ovine PACAP38 (oPACAP38) and PACAP27 (oPACAP27), but not vasoactive intestinal polypeptide (VIP). A lack of GH response to VIP stimulation is consistent with the pharmacological properties of PAC-1 receptors, suggesting that this receptor subtype may be involved in PACAP-induced GH secretion in carp species. Although the maximal GH responses induced by oPACAP38 and oPACAP27 were similar, the minimal effective dose and ED50 value for oPACAP38 were significantly lower than that for oPACAP27. These results may indicate that common carp PAC-1 receptors are more sensitive to stimulation by oPACAP38 than by oPACAP27. In parallel studies, oPACAP38 and oPACAP27 were also effective in increasing cAMP release, cellular cAMP content, total cAMP production, and intracellular Ca²⁺ ([Ca²⁺]_i) levels in common carp pituitary cells. Besides, the rise in [Ca²⁺]_i induced by oPACAP38 was blocked by removing extracellular Ca²⁺ ([Ca²⁺]_e) or by treatment with nifedipine, an inhibitor of voltage-sensitive Ca²⁺ channels (VSCC). The dose dependence of PACAP-stimulated GH release in common carp pituitary cells was mimicked by activating adenylate cyclase using forskolin, inhibiting cAMP degradation using IBMX, increasing functional levels of intracellular cAMP using CPT-cAMP, or inducing [Ca²⁺]_e entry using the Ca²⁺ ionophore A23187. In contrast, the GH-releasing effect of oPACAP38 was suppressed by treatment with the adenylate cyclase inhibitor MDL12330A, protein kinase A inhibitor H89, and VSCC blocker nifedipine, or by perifusion with a Ca²⁺-free culture medium. These results, as a whole, suggest that PACAP functions as a GH-releasing factor in common carp by activating pituitary receptors resembling mammalian PAC-1 receptors. Apparently, the GH-releasing action of PACAP is mediated through the adenylate cyclase/cAMP/protein kinase A pathway and [Ca²⁺]_e influx through VSCC.

show abstract

Section: Discussionsupporting

confidence: 75%

Regulation of Growth Hormone Release in Common Carp Pituitary Cells by Pituitary Adenylate Cyclase-Activating Polypeptide: Signal Transduction Involves cAMP- and Calcium-Dependent Mechanisms

et al. 2002

View full text Add to dashboard Cite

show abstract

“…In agreement with the presence of GnRH receptors in somatotropes as stated above, GnRHs have been demonstrated to increase GH release in vitro from dispersed rat pituitary cells ( 4 ), and to stimulate Gh release in most of teleosts examined, including goldfish ( 5 , 65 , 66 ), grass carp ( 7 ), common carp ( 7 , 8 ), and tilapia ( 67 ). In rainbow trout, however, the role of GnRH as a GH-releasing factor is not clear.…”

Section: Discussionsupporting

confidence: 57%

“…In rats, GnRH was shown to increase GH release in vitro from hemipituitaries in combination with enkephalin ( 3 ) and perifused pituitary cells ( 4 ). In teleosts, GnRHs have also been shown to stimulate GH release from cultured pituitary cells of goldfish ( 5 ) and tilapia ( 6 ), and from pituitary fragments of common carp ( 7 , 8 ). Moreover, GnRHs have also been demonstrated to upregulate gh mRNA in some teleosts including the goldfish ( 9 ), common carp ( 10 ), blue gourami fish ( 11 ), and masu salmon ( 12 ).…”

Section: Introductionmentioning

confidence: 99%

A Type IIb, but Not Type IIa, GnRH Receptor Mediates GnRH-Induced Release of Growth Hormone in the Ricefield Eel

et al. 2018

View full text Add to dashboard Cite

Multiple gonadotropin-releasing hormone receptors (GnRHRs) are present in vertebrates, but their differential physiological relevances remain to be clarified. In the present study, we identified three GnRH ligands GnRH1 (pjGnRH), GnRH2 (cGnRH-II), and GnRH3 (sGnRH) from the brain, and two GnRH receptors GnRHR1 (GnRHR IIa) and GnRHR2 (GnRHR IIb) from the pituitary of the ricefield eel Monopterus albus. GnRH1 and GnRH3 but not GnRH2 immunoreactive neurons were detected in the pre-optic area, hypothalamus, and pituitary, suggesting that GnRH1 and GnRH3 may exert hypophysiotropic roles in ricefield eels. gnrhr1 mRNA was mainly detected in the pituitary, whereas gnrhr2 mRNA broadly in tissues of both females and males. In the pituitary, GnRHR1 and GnRHR2 immunoreactive cells were differentially distributed, with GnRHR1 immunoreactive cells mainly in peripheral areas of the adenohypophysis whereas GnRHR2 immunoreactive cells in the multicellular layers of adenohypophysis adjacent to the neurohypophysis. Dual-label fluorescent immunostaining showed that GnRHR2 but not GnRHR1 was localized to somatotropes, and all somatotropes are GnRHR2-positive cells and vice versa at all stages examined. GnRH1 and GnRH3 were shown to stimulate growth hormone (Gh) release from primary culture of pituitary cells, and to decrease Gh contents in the pituitary of ricefield eels 12 h post injection. GnRH1 and GnRH3 stimulated Gh release probably via PLC/IP3/PKC and Ca2+ pathways. These results, as a whole, suggested that GnRHs may bind to GnRHR2 but not GnRHR1 to trigger Gh release in ricefield eels, and provided novel information on differential roles of multiple GnRH receptors in vertebrates.

show abstract

“…For example, Islinger et al (2003) reported ultrastructural changes in the livers and testes of zebrafish, Danio rerio; Flynn & Benfey (2007) found mottled livers, swollen kidneys, and reduced gonad size in shortnose sturgeons, Acipenser brevirostrum; and Hendry et al (2003) detailed irreversible injuries in Atlantic halibut, Hippoglossus hippoglossus L. including spinal deformities and high mortality rates, after E2 treatment. One possible explanation of these anomalies in growth and development may be related to altered interactions between sex steroids, growth hormone, and thyroid hormones (De Jesus et al, 1992;Lin et al, 1995) produced by the exogenous exposure to E2.…”

Section: Discussionmentioning

confidence: 99%

Functional feminization of the Mexican snook (Centropomus poeyi) using 17β estradiol in the diet

Vidal-López

Contreras-Sánchez

Hernández‐Franyutti

et al. 2019

LAJAR

View full text Add to dashboard Cite

The Mexican snook, Centropomus poeyi, supports an important fishery in southeastern Mexico. Due to its protandrous hermaphroditism, females may be especially sensitive to overfishing because they tend to be larger and selective removal has the potential to negatively affect natural populations, thus making urgent the need to contribute on management strategies for the species. The objective of this study was to produce batches of reproductive females at an early age and a small size by using 17β-estradiol (E2) in the diet. In two separate experiments, we fed fish 0, 10, 20, 30, 40, 50, or 60 mg of 17β-estradiol per kg of food for 60 days during gonadal differentiation. Fish fed with 50 and 60 mg of E2 per kg of food resulted in 100% feminization, while the control group (0 mg of E2) was 100% male. Three years after feminization, sex-reversed fish remained female, producing oocytes and were capable of spawning, while fish in the control group were ripe males with running milt. E2-treated groups were significantly larger (weight and length) than the control groups for up to six months after treatment, but the difference was undetectable at 300 days post-treatment. Survival was high in all treatments (100%). We obtained high percentages of functional females using dosages of 50 and 60 mg kg -1 of E2 for 60 days, with 80% of the induced fish spawning and producing fertilized eggs and larvae. The results obtained in this study provide opportunities for broodstock management and sex manipulation.

show abstract

Effects of gonadotropin-releasing hormone (GnRH) analogs and sex steroids on growth hormone (GH) secretion and growth in common carp (Cyprinus carpio) and grass carp (Ctenopharyngodon idellus)

Cited by 24 publications

References 10 publications

Regulation of Growth Hormone Release in Common Carp Pituitary Cells by Pituitary Adenylate Cyclase-Activating Polypeptide: Signal Transduction Involves cAMP- and Calcium-Dependent Mechanisms

Regulation of Growth Hormone Release in Common Carp Pituitary Cells by Pituitary Adenylate Cyclase-Activating Polypeptide: Signal Transduction Involves cAMP- and Calcium-Dependent Mechanisms

A Type IIb, but Not Type IIa, GnRH Receptor Mediates GnRH-Induced Release of Growth Hormone in the Ricefield Eel

Functional feminization of the Mexican snook (Centropomus poeyi) using 17β estradiol in the diet

Contact Info

Product

Resources

About