Application of in vitro [35S]GTPγ-S autoradiography in studies of growth hormone effects on opioid receptors in the male rat brain

Growth hormone (GH) is secreted as pulses in vivo. To understand the signals governing this periodicity, we have established a perifusion-based model of pulsatile GH release. Male rat anterior pituitaries were dispersed and perifused with pulses of human growth hormone-releasing factor-(1--40) (GHRF), with or without a continuous or discontinuous somatostatin tonus. An experiment was composed of a 1-h base-line collection followed by four 3-h cycles; each contained single or paired 10-min infusion(s) of 3 nM GHRF. In testing the impact of somatostatin, the protocol was identical except that 0.3 nM somatostatin was added 30 min into the base-line period and then was either continued throughout the study or withdrawn during the periods of GHRF infusion. GH base lines with somatostatin were lower than vehicle base lines (P less than 0.05). GHRF pulses generated consistent peaks of GH release between 200 and 300 ng. min-1. (10(7) cells)-1, and these peaks were not altered by continuous somatostatin. In contrast, withdrawal of somatostatin during GHRF administration elicited markedly higher GH peaks (P less than 0.05) and more total GH release (P less than 0.05). This response could not be accounted for by the additive effects of GHRF and somatostatin withdrawal.

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Metabolic effects of the major component of bovine growth hormone

Biochemical Journal ◽

10.1042/bj1220633 ◽

1971 ◽

Vol 122 (5) ◽

pp. 633-640 ◽

Cited By ~ 5

Author(s):

N. I. Swislocki ◽

M. Sonenberg ◽

M. Kikutani

Keyword(s):

Growth Hormone ◽

Deae Cellulose ◽

Heterogeneous Material ◽

Parent Material ◽

Metabolic Effects ◽

Sedimentation Equilibrium ◽

Bovine Growth Hormone ◽

Hormone Effects

Bovine growth hormone, subjected to DEAE-cellulose chromatography, yielded one major and several minor components. The various chromatographic fractions of bovine growth hormone were compared with the parent material for their ability to promote hormone effects in vivo and in vitro. The major component of bovine growth hormone was homogeneous by acrylamide-gel electrophoresis, rechromatography and sedimentation equilibrium. Its amino acid composition was similar to that of the parent hormone. The major component possessed all the qualitative activities present in the original heterogeneous material, including promotion of acute hypoglycaemia and hypolipaemia. In studies in vitro in adipose-tissue segments the major component of the hormone increased entry of glucose and its oxidation to CO2, conversion of glucose into glyceride glycerol, release of glycerol and incorporation of histidine into adiposetissue protein. Other chromatographic fractions of bovine growth hormone were not homogeneous and possessed some but not all of the metabolic activities attributed to the hormone preparations or its major component. Thus, the metabolic effects obtained with bovine growth-hormone preparations in vivo and in vitro can be obtained with the major homogeneous component of the hormone. This observation precludes the possibility that the metabolic effects obtained with bovine growth-hormone preparations are due to the combined actions of a number of components found therein.

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Interaction of β-casomorphins with multiple opioid receptors: In vitro and in vivo studies in the newborn rat brain

Developmental Brain Research ◽

10.1016/0165-3806(86)90126-4 ◽

1986 ◽

Vol 30 (1) ◽

pp. 25-30 ◽

Cited By ~ 10

Author(s):

Andrea Volterra ◽

Patrizia Restani ◽

Nicoletta Brunello ◽

Corrado L. Galli ◽

Giorgio Racagni

Keyword(s):

Rat Brain ◽

Opioid Receptors ◽

In Vivo Studies ◽

Newborn Rat

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Growth hormone effects on in vitro metabolism of avian adipose and liver tissue

General and Comparative Endocrinology ◽

10.1016/0016-6480(77)90046-6 ◽

1977 ◽

Vol 33 (3) ◽

pp. 322-328 ◽

Cited By ~ 55

Author(s):

S. Harvey ◽

C.G. Scanes ◽

T. Howe

Keyword(s):

Growth Hormone ◽

Liver Tissue ◽

In Vitro Metabolism ◽

Hormone Effects

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ESTIMATION OF PROLACTIN AND GROWTH HORMONE LEVELS BY POLYACRYLAMIDE DISC ELECTROPHORESIS

Journal of Endocrinology ◽

10.1677/joe.0.0450183 ◽

1969 ◽

Vol 45 (2) ◽

pp. 183-NP ◽

Cited By ~ 38

Author(s):

C. S. NICOLL ◽

J. A. PARSONS ◽

R. P. FIORINDO ◽

C. W. NICHOLS

Keyword(s):

Growth Hormone ◽

Adult Male ◽

Prolactin Secretion ◽

Disc Electrophoresis ◽

Male Rat ◽

Rat Pituitary ◽

Hypothalamic Tissue ◽

Prolactin Content ◽

High Degree

SUMMARY A procedure for estimating rat prolactin and growth hormone (somatotrophin, STH), by measuring the optical density of the electrophoretically isolated and stained hormone bands in polyacrylamide gel columns, is described and evaluated. A simple and inexpensive densitometer is also described. Prolactin levels in adenohypophyses and in medium from pituitary incubates were measured by electrophoresis-densitometry (ED) and by the pigeon crop-sac assay. The two methods showed a high degree of correlation. The validity of the ED method for estimating prolactin levels in adenohypophysial tissue and in incubation medium was demonstrated by comparing the prolactin content of adult male and female and of oestrogen-treated male glands and by experiments in vitro. The female pituitary contained about three times more prolactin than the male and the glands of oestrogen-treated males had levels about the same as those of females. It was also shown that the ED method could be used to demonstrate the inhibitory effects of extract of rat hypothalamic tissue on prolactin secretion in vitro by the rat pituitary. Levels of STH in adult male glands, as measured by this method, were comparable to results obtained by others using immunoassays. Propylthiouracil-induced hypothyroidism depressed the STH and prolactin levels in male rat pituitaries, in agreement with the observations of others. The stainability of the prolactin band in rat adenohypophyses was observed to decrease with time when the glands were stored on dry ice. No such change occurred in the staining characteristics of the STH band. Other aspects of the ED method are discussed, including its precision, efficiency, sensitivity, economy and utility.

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