Pigment dispersion by prolactin in cultured xanthophores and erythrophores of some fish species

Oshima, Nobuyuki; Makino, Mihoko; Iwamuro, Shawichi; Bern, Howard A.

doi:10.1002/(sici)1097-010x(19960501)275:1<45::aid-jez7>3.0.co;2-a

Cited by 30 publications

(25 citation statements)

References 11 publications

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“…In this case, a higher affinity for PRL 188 was observed and a correspondingly lower concentration of hormone was required to activate the Jak2/Stat5 pathway (Sohm et al, 1998). In addition, different potencies were reported for the two prolactins with regard to their effect on pigment dispersion in cultured xanthophores and erythrophores (Oshima et al, 1996). Pigment dispersion was affected by nanomolar concentrations of tilapia PRL 177 but only by micromolar concentrations of tilapia PRL 188 .…”

Section: Both Tilapia Prolactin Receptors Are Widely Expressed and Rementioning

confidence: 90%

A novel tilapia prolactin receptor is functionally distinct from its paralog

Fiol

Sanmarti

Sacchi

et al. 2009

Journal of Experimental Biology

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Section: Both Tilapia Prolactin Receptors Are Widely Expressed and Rementioning

confidence: 90%

A novel tilapia prolactin receptor is functionally distinct from its paralog

Fiol

Sanmarti

Sacchi

et al. 2009

Journal of Experimental Biology

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“…In addition to GH, the tilapia pituitary secretes two forms of prolactin (tPRL177 and tPRL188), one of which contain 177 amino acid residues, and the other, 188 amino acid residues. These two prolactins, to which unique functions have been ascribed (Rubin & Specker 1992, Oshima et al 1996, are encoded by separate genes and share only 69% sequence identity (Specker et al 1985, Rentier-Delrue et al 1989, Yamaguchi et al 1991. In this study, we report the effects of KP-102 treatment on circulating GH and PRL(s) levels in a cichlid teleost.…”

Section: Introductionmentioning

confidence: 99%

The hexapeptide KP-102 (D-ala-D-beta-Nal-ala-trp-D-phe-lys-NH(2)) stimulates growth hormone release in a cichlid fish (Ooreochromis mossambicus)

Shepherd

Eckert²,

Parhar³

et al. 2000

Journal of Endocrinology

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Studies in mammals have shown that synthetic Metenkephalin derivatives, called growth hormone-releasing peptides (GHRPs), stimulate growth hormone (GH) release. The present study was conducted to determine whether the GHRP, KP-102, specifically stimulates GH release in a teleost. Tilapia (Oreochromis mossambicus) were given a single intraperitoneal injection of KP-102 (D-Ala-D-Β-Nal-Ala-Trp-D-Phe-Lys-NH2) or bovine GHRH1-29-amide or vehicle and blood was sampled at 1, 6 and 12 h after injection. KP-102 was administered at two doses of 1 ng/g and 10 ng/g body weight, whereas GHRH (positive control) was administered at a single dose of 10 ng/g body weight. Plasma levels of tilapia GH and prolactins (tPRL177 and tPRL188) were determined by radioimmunoassay. As expected, GHRH injection significantly (P<0.001) elevated plasma GH levels (ng/ml) in tilapia at 6 h post-injection. KP-102 also significantly elevated GH levels (at the low dose) at 6 (P<0.05) and 12 (P<0.01) hours post-injection. There were no significant effects on plasma PRL(s) levels, although mean levels of both PRLs were elevated at 6 h post-injection. These results show for the first time that GHRPs stimulate GH release in teleosts and suggest that the GHRP receptor and possibly a "Ghrelin-like" ligand are also present in lower vertebrates.

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“…The amino acid sequence identity of the two prolactins is only 69%, with each form being encoded by separate genes (Yamaguchi et al 1988, Rentier-Delrue et al 1989. Given these differences, studies have aimed at determining their unique physiological functions in ion and water balance (Specker et al 1985, Young et al 1988, Specker et al 1989, Auperin et al 1994, 1995, Flik et al 1994, growth (Shepherd et al 1997b), reproduction (Rubin & Specker 1992, Oshima et al 1996 and pigmentation (Kitta et al 1993, Oshima et al 1996. Both forms of PRL are colocalized within the same cells of the rostral pars distalis (RPD) of the pituitary , Specker et al 1993, but when the ratio of the two prolactins (tPRL 188 :tPRL 177 ) is examined, it becomes evident that they are differentially regulated during development (Ayson et al 1994), and by changes in environmental salinity (Borski et al 1992, Auperin et al 1994, Yada et al 1994, Yoshikawa-Ebesu et al 1995 and nutrition (Vijayan et al 1996, Shepherd et al 1997a.…”

Section: Introductionmentioning

confidence: 99%

Is the primitive regulation of pituitary prolactin (tPRL177 and tPRL188) secretion and gene expression in the euryhaline tilapia (Oreochromis mossambicus) hypothalamic or environmental?

Shepherd¹,

Sakamoto

Hyodo³

et al. 1999

Journal of Endocrinology

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We examined the effects of environmental salinity on circulating levels of the two prolactins (tPRL 177 and tPRL 188 ) and levels of pituitary tPRL 177 and tPRL 188 mRNA in the euryhaline tilapia, Oreochromis mossambicus. Fish were sham-operated or hypophysectomized and the rostral pars distalis (RPD) autotransplanted onto the optic nerve. Following post-operative recovery in ¼ seawater, tilapia were transferred to fresh water (FW), ¼ seawater (SW) or SW. Serum tPRL 177 and tPRL 188 levels in sham-operated and RPD-autotransplanted fish were highest in FW and decreased as salinity was increased. tPRL 177 and tPRL 188 mRNA levels in RPD implants as well as in pituitaries from the sham-operated fish were also highest in FW and decreased with increasing salinity. Serum osmolality increased with salinity, with the highest levels occurring in the seawater groups. We conclude that some plasma factor (probably plasma osmolality), in the absence of hypothalamic innervation, exerts a direct regulatory action on prolactin release and gene expression in the pituitary of O. mossambicus. This regulation is in accord with the actions of the two prolactins in the freshwater osmoregulation of the tilapia.

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Pigment dispersion by prolactin in cultured xanthophores and erythrophores of some fish species

Cited by 30 publications

References 11 publications

A novel tilapia prolactin receptor is functionally distinct from its paralog

A novel tilapia prolactin receptor is functionally distinct from its paralog

The hexapeptide KP-102 (D-ala-D-beta-Nal-ala-trp-D-phe-lys-NH(2)) stimulates growth hormone release in a cichlid fish (Ooreochromis mossambicus)

Is the primitive regulation of pituitary prolactin (tPRL177 and tPRL188) secretion and gene expression in the euryhaline tilapia (Oreochromis mossambicus) hypothalamic or environmental?

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