Development of radioimmunoassay for eel growth hormone.

Kishida, Michiko; Hirano, Tetsuya

doi:10.2331/suisan.54.1321

Cited by 26 publications

(14 citation statements)

References 9 publications

(9 reference statements)

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“…Two possible reasons for this difference in "basal" growth hormone levels in trout in good condition are discussed in detail in an accompanying paper (Le Bail et al, 1991). In contrast to these findings, Kishida and Hirano (1988) did not find any difference in plasma growth hormone levels between fed and starved eels. Although the homologous growth hormone RIA they employed was quite sensitive, most fed and starved eels had undetectable plasma growth hormone levels.…”

Section: Discussioncontrasting

confidence: 51%

The effect of starvation on growth and plasma growth hormone concentrations of rainbow trout, Oncorhynchus mykiss

Sumpter

Bail

Pickering

et al. 1991

General and Comparative Endocrinology

168

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Two experiments, one using 0+ the other 1 + rainbow trout, were conducted to investigate the effect of prolonged starvation on plasma growth hormone levels. The results from both experiments were essentially the same. As expected, starvation resulted in cessation of growth and in a lower coefficient of condition, whereas fed fish continued to grow and remained in good condition. Starvation had relatively little effect on the plasma cortisol level; in one experiment levels were elevated temporarily in starved fish, although by the end of the experiment there was no longer any difference between starved and fed fish, and in the other experiment plasma cortisol levels remained very low throughout the course of the experiment in both starved and fed fish. In contrast, in both experiments starvation had a pronounced effect on the plasma growth hormone level, which rose steadily during both experiments, such that it was six times higher after 1 month of starvation in 0+ fish. and five times higher after 6 weeks of starvation in 1 + fish. Thus, paradoxically, fed fish had very low plasma growth hormone levels and grew rapidly, whereas starved fish had elevated plasma growth hormone levels but did not grow. In both experiments a strong negative correlation was observed between the plasma growth hormone level and the coefficient of condition of the fish. The results are discussed with regard to the well-established metabolic changes that occur during starvation, and it is suggested that a major role of growth hormone during starvation is to aid in the mobilisation of fatty acids and glycerol from adipose stores.

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Section: Discussioncontrasting

confidence: 51%

The effect of starvation on growth and plasma growth hormone concentrations of rainbow trout, Oncorhynchus mykiss

Sumpter

Bail

Pickering

et al. 1991

General and Comparative Endocrinology

168

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“…Both production and secretion of GH in the eel pituitary seem to be normally under tonic inhibitory control, most likely by the hypothalamus, although presence of potential inhibitory factors in the blood is also possible. This seems to be in agreement with extremely low levels of GH in the eel plasma (less than 0.2 ng/ml; Kishida and Hirano 1988), although this could also be due to an extremely high metabolic clearance of the hormone. In the eel, SRIF fibers terminate on the basal lamina along GH cells, and changes in SRIF immunoreactivity have been observed after starvation suggesting that SRIF regulates GH release in the eel (Olivereau et al 1984).…”

Section: Discussionsupporting

confidence: 66%

“…The eel GH RIA is more sensitive than the densitometric method; the minimum detectable levels of GH were 10 pg in the RIA (Kishida and Hirano 1988) and 1.5 + 0.3 tAg ovine PRL (mean + SEM, n = 6) in the densitometry. Furthermore, interassay coefficients of variation, calculated using the midrange of the assay, were 13.8% (n = 4) in the RIA and 17.7% (n = 3) in the densitometry.…”

Section: Discussionmentioning

confidence: 99%

“…Total contents of the two GHs in the culture medium and the pituitary extract were measured by a homologous RIA using rabbit antiserum against GH I which does not distinguish between two forms of the eel GH (Kishida and Hirano 1988). The culture medium (0.2 ml) and pituitary extract (0.2 ml) were also subjected to polyacrylamide disc electrophoresis at pH 9.5, as described by Davis (1964).…”

Section: Methodsmentioning

confidence: 99%

“…A homologous and specific radioimmunoassay (RIA) which does not distinguish between the two forms has also been established recently (Kishida and Hirano 1988). The present study was undertaken to examine the effects of osmolality of the culture media and of somatostatin on GH release, using RIA for measurement of total levels of eel GHs, during incubation in a defined medium for 2 weeks.…”

Section: Introductionmentioning

confidence: 99%

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Growth hormone secretion during longterm incubation of the pituitary of the Japanese eel, Anguilla japonica

Suzuki

Kishida

Hirano

1990

Fish Physiol Biochem

Self Cite

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Growth hormone (GH) secretion from organ-cultured pituitaries of the eel (Anguilla japonica) was studied during incubation in a defined medium for 2 weeks, using a homologous radioimmunoassay which does not distinguish between the two molecular forms of eel GH. The total amount of GH secreted increased gradually during the incubation period; so that the amount of GH released on day 14 was about 30 times greater than that on day 1. On day 14, the proportion of GH released relative to the total amount of GH present (the sum of GH released into the medium and residual content in the pituitary) was 96% and the amount produced on day 14 was 4 times greater than the content in the unincubated pituitary. Somatostatin (SRIF, 1.8 × 10(-7) M) inhibited the increase in GH release. On day 7, the proportion of GH released by pituitaries treated with SRIF (28%) was less than that released by the control pituitary (91%). There was no significant difference in GH release between the pituitaries incubated in isotonic medium (300 mOsm) and those in hypotonic medium (240 mOsm) for 2 weeks except for the first 3 days, when the pituitaries in hypotonic medium secreted significantly greater amounts of GH than those incubated under isotonic condition. Hypertonic medium (350 mOsm) had no effect on GH release except for significant inhibition on days 6 and 14. When secretion of the two forms of GH (GH I and II) was examined after separation by polyacrylamide gel electrophoresis followed by densitometry, slightly more GH I tended to be secreted than GH II during the culture period, although the effects of SRIF and osmolality of the media on GH I release were similar to those on GH II. It is concluded that GH secretion and production in the eel is mainly under the inhibitory control of hypothalamus, and that osmolality has a minimum influence on the GH release.

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Isolation and Characterization of a Homologue of Mammalian Prolactin-Releasing Peptide from the Tilapia Brain and Its Effect on Prolactin Release from the Tilapia Pituitary

Seale

Itoh

Moriyama

et al. 2002

General and Comparative Endocrinology

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Development of radioimmunoassay for eel growth hormone.

Cited by 26 publications

References 9 publications

The effect of starvation on growth and plasma growth hormone concentrations of rainbow trout, Oncorhynchus mykiss

The effect of starvation on growth and plasma growth hormone concentrations of rainbow trout, Oncorhynchus mykiss

Growth hormone secretion during longterm incubation of the pituitary of the Japanese eel, Anguilla japonica

Isolation and Characterization of a Homologue of Mammalian Prolactin-Releasing Peptide from the Tilapia Brain and Its Effect on Prolactin Release from the Tilapia Pituitary

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