Determination of tissue and plasma concentrations of PTHrP in fish: development and validation of a radioimmunoassay using a teleost 1–34 N-terminal peptide

Rotllant, Josep; Worthington, GP; Fuentes, Juan; Guerreiro, Pedro M.; Teitsma, Christine A.; Ingleton, P. M.; Balment, R. J.; Canário, Adelino V.M.; Power, Deborah M.

doi:10.1016/s0016-6480(03)00166-7

Cited by 41 publications

(37 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Animal handling followed the approved universitary guidelines. Plasma PTHrP level (nmoll-') was measured with a homologous radioimmunoassay according to Rotllant et al (2003) and plasma calcitriol (pmoll-') was measured according to Hoof van et al (1993).…”

Section: Fishmentioning

confidence: 99%

Melatonin synthesis under calcium constraint in gilthead sea bream (Sparus auratus L.)

Abbink

Kulczykowska

Kalamarz

et al. 2008

General and Comparative Endocrinology

View full text Add to dashboard Cite

Brain or blood plasma melatonin was analysed as a measure for pineal melatonin production in sea bream. Access to calcium was limited by diluting the seawater to 2.5& and removing calcium from the diet or by prolonged feeding of vitamin D-deficient diet. Inter actions/relations between melatonin and calcium balance and the hypercalcemic endocrines PTHrP and calcitriol were assessed. Restrict ing calcium availability in both water and diet had no effect on plasma melatonin, but when calcium was low in the water or absent from food, increased and decreased plasma melatonin was observed, respectively. Fish on a vitamin D-deficient diet (D-fish) showed decreased plasma calcitriol levels and remained normocalcemic. Decreased brain melatonin was found at all sampling times (10-22 weeks) in the D -fish compared to the controls. A positive correlation between plasma Ca2+ and plasma melatonin was found (R2 = 0.19; N = 41; P < 0.01) and brain melatonin was negatively correlated with plasma PTHrP (R2 = 0.78; N = 4; P < 0.05). The posi tive correlation between plasma levels of melatonin and Ca2+ provides evidence that melatonin synthesis is influenced by plasma Ca2+. The decreased melatonin production in the D -fish points to direct or indirect involvement of calcitriol in melatonin synthesis by the pineal organ in teleosts. The hypercalcemic factors PTHrP and calcitriol appeared to be negatively correlated with melatonin and this substantiates an involvement of melatonin in modulating the endocrine response to cope with hypocalcemia. It further points to the importance of Ca2+ in melatonin physiology.

show abstract

Section: Fishmentioning

confidence: 99%

Melatonin synthesis under calcium constraint in gilthead sea bream (Sparus auratus L.)

Abbink

Kulczykowska

Kalamarz

et al. 2008

General and Comparative Endocrinology

View full text Add to dashboard Cite

show abstract

“…PTHrP was quantified in plasma by radioimmunoassay using heterologous antisera raised against human peptide (Danks et al, 1993;Devlin et al, 1996) and later with homologous antisera (Rotllant et al, 2003;Abbink et al, 2004Abbink et al, , 2006. As holds for elasmobranch species, PTHrP levels in teleostean plasma are consistently and significantly higher than these values for humans (basal circulating lev els of around 0.5-2.5 pmol l_1 in humans and 0.1 0.6 nmol l_1 in fish).…”

Section: Pthrp In Teleostsmentioning

confidence: 99%

Parathyroid hormone-related protein in teleost fish

Abbink

Flik

2007

General and Comparative Endocrinology

View full text Add to dashboard Cite

A brief description is given of the discovery of PTHrP and the roles of the peptide in mammalian physiology. Next, the occurrence of PTHrP in the earliest vertebrates, sharks, skates and fishes, is reviewed and the calciotropic functions of PTHrP are addressed more spe cifically in fishes. Parathyroid hormone-related protein (PTHrP) is a hypercalcemic hormone in teleostean fishes, but also has para-and autocrine functions. After the isolation and identification of fish PTHrP and PTHrP receptors and the subsequent development of recom binant protein and a real-time quantitative PCR, a calciotropic role of PTHrP in fish physiology could be assessed. PTHrP influences calcium physiology via regulation of calcium mobilisation from internal sources (bone and scales) and via calcium uptake from the envi ronment (water and diet). Continuous variations in the need for calcium and in the availability of environmental calcium require fast calciotropes to guarantee calcium balance, in which PTHrP is pivotal for the fish. PTHrP is essential in fish bone physiology, e.g. in min eralisation and calcium reabsorption from the scales. Moreover, PTHrP plays a role in vitellogenesis, cortisol production, regulation of renal Mrp2 activity and melatonin synthesis. The plethora of functions of PTHrP in fish concern endocrine, paracrine and autocrine (and possibly intracrine) functions; calciotropic actions of PTHrP at the organismal and cellular level are prominent in fish. The strong con servation of the pthrp gene in the vertebrate lineage and the N-terminal similarity of the coded proteins relates to the important role of PTHrP in calcium physiology that is of paramount importance to all physiological processes. Recent and ongoing studies will contribute to our rapidly expanding knowledge of the original physiological functions of PTHrP in teleost fish.

show abstract

“…Antisera were added to all tubes except those used to determine total count (cpm) and non-specific binding. In both the T 3 and the T 4 assay, the tubes were incubated for 16-24 h at 4°C and, subsequently, the free hormone was separated from the bound hormone, using precipitation with a secondary antibody (Rotllant et al 2003).…”

Section: Thyroid Hormone Radioimmunoassaymentioning

confidence: 99%

Thyroid and pituitary gland development from hatching through metamorphosis of a teleost flatfish, the Atlantic halibut

et al. 2005

View full text Add to dashboard Cite

Fish larval development, not least the spectacular process of flatfish metamorphosis, appears to be under complex endocrine control, many aspects of which are still not fully elucidated. In order to obtain data on the functional development of two major endocrine glands, the pituitary and the thyroid, during flatfish metamorphosis, histology, immunohistochemistry and in situ hybridization techniques were applied on larvae of the Atlantic halibut (Hippoglossus hippoglossus), a large, marine flatfish species, from hatching through metamorphosis. The material was obtained from a commercial hatchery. Larval age is defined as day-degrees (D°=accumulated daily temperature from hatching). Sporadic thyroid follicles are first detected in larvae at 142 D°(27 days post-hatch), prior to the completion of yolk sack absorption. Both the number and activity of the follicles increase markedly after yolk sack absorption and continue to do so during subsequent development. The larval triiodothyronine (T 3 ) and thyroxine (T 4 ) content increases, subsequent to yolk absorption, and coincides with the proliferation of thyroid follicles. A second increase of both T 3 and T 4 occurs around the start of metamorphosis and the T 3 content further increases at the metamorphic climax. Overall, the T 3 content is lower than T 4 . The pituitary gland can first be distinguished as a separate organ at the yolk sack stage. During subsequent development, the gland becomes more elongated and differentiates into neurohypophysis (NH), pars distalis (PD) and pars intermedia (PI). The first sporadic endocrine pituitary cells are observed at the yolk sack stage, somatotrophs (growth hormone producing cells) and somatolactotrophs (somatolactin producing cells) are first observed at 121 D°( 23 days post-hatch), and lactotrophs (prolactin producing cells) at 134 D°(25 days post-hatch). Scarce thyrotrophs are evident after detection of the first thyroid follicles (142 D°), but coincident with a phase in which follicle number and activity increase (260 D°). The somatotrophs are clustered in the medium ventral region of the PD, lactotrophs in the anterior part of the PD and somatolactotrophs are scattered in the mid and posterior region of the pituitary. At around 600 D°, coinciding with the start of metamorphosis, somatolactotrophs are restricted to the interdigitating tissue of the NH. During larval development, the pituitary endocrine cells become more numerous. The present data on thyroid development support the notion that thyroid hormones may play a significant role in Atlantic halibut metamorphosis. The time of appearance and the subsequent proliferation of pituitary somatotrophs, lactotrophs, somatolactotrophs and thyrotrophs indicate at which stages of larval development and metamorphosis these endocrine cells may start to play active regulatory roles.

show abstract

Determination of tissue and plasma concentrations of PTHrP in fish: development and validation of a radioimmunoassay using a teleost 1–34 N-terminal peptide

Cited by 41 publications

References 27 publications

Melatonin synthesis under calcium constraint in gilthead sea bream (Sparus auratus L.)

Melatonin synthesis under calcium constraint in gilthead sea bream (Sparus auratus L.)

Parathyroid hormone-related protein in teleost fish

Thyroid and pituitary gland development from hatching through metamorphosis of a teleost flatfish, the Atlantic halibut

Contact Info

Product

Resources

About