Hormonal control of in vitro vitellogenin synthesis in Rana esculenta liver: Effects of mammalian and amphibian growth hormone

1992 ◽  
Vol 88 (3) ◽  
pp. 406-414 ◽  
Author(s):  
Oliana Carnevali ◽  
Gilberto Mosgoni ◽  
Kazutoshi Yamamoto ◽  
Tetsuya Kobayashi ◽  
Sakae Kikuyama ◽  
...  
1993 ◽  
Vol 137 (3) ◽  
pp. 383-389 ◽  
Author(s):  
O. Carnevali ◽  
G. Mosconi ◽  
K. Yamamoto ◽  
T. Kobayashi ◽  
S. Kikuyama ◽  
...  

ABSTRACT Male and female Rana esculenta liver was induced in an in-vitro system by homologous and Rana catesbeiana pituitary to synthesize and release vitellogenin, a lipoglycophosphoprotein precursor of yolk proteins, lipovitellins and phosvitins, in oviparous vertebrates. In the present experiments, the action of prolactin on hepatic vitellogenin synthesis and release was investigated, using ovine prolactin and Rana catesbeiana prolactin. The effects of prolactin on hepatic vitellogenin synthesis displayed different trends related to sex; male liver was found to be more responsive than female liver to both ovine and frog prolactin; moreover, the response to prolactin was dose-related (r = 0·998; P <0·05) in male but not in female liver. In both sexes, a high degree of seasonality in the responsiveness of the liver was found, since the vitellogenin levels induced by prolactin during the winter phase were significantly (P < 0·001) higher than those produced during the summer phase. Thus, there was no significant difference between the action of ovine and frog prolactin on vitellogenin synthesis; in fact, mammalian prolactins are structurally similar with regard to nucleotide and amino acid sequences. The direct action of prolactin on hepatic vitellogenin synthesis in the frog Rana esculenta is discussed, on the basis of the role played by prolactin as an important growth modulatory hormone in fetal and adult tissues. Journal of Endocrinology (1993) 137, 383–389


2002 ◽  
Vol 283 (3) ◽  
pp. C673-C678 ◽  
Author(s):  
G. Mosconi ◽  
O. Carnevali ◽  
H. R. Habibi ◽  
R. Sanyal ◽  
A. M. Polzonetti-Magni

Experiments were carried out to study in vitro the effects of 17β-estradiol (E2), homologous pituitary homogenate (HPH), and recombinant red sea bream growth hormone (sbGH) on vitellogenin (VTG) secretion from cultured sea bream liver fragments. Basal secretion of VTG was found to be significantly higher in the prespawning period, compared with sea bream liver in the spawning and postspawning periods. Similarly, the sea bream liver obtained during the prespawning period responded more significantly to treatments with E2, HPH, or sbGH compared with sea bream liver during spawning. In the postspawning period, treatments with E2, HPH, or sbGH were without significant effect on VTG secretion level in sea bream liver. The level of E2receptors was also analyzed by Western blot analysis. The result demonstrates a significantly higher level of E2 receptors in the sea bream liver at the prespawning stage compared with those at the spawning and postspawning stages. The findings support the hypothesis that homologous upregulation of estrogen receptors plays an important role in the estrogen-sensitive control of VTG synthesis in the sea bream liver.


Life Sciences ◽  
2000 ◽  
Vol 67 (12) ◽  
pp. 1467-1476 ◽  
Author(s):  
Oliana Carnevali ◽  
Gilberto Mosconi ◽  
Alberta Maria Polzonetti-Magni

1967 ◽  
Vol 54 (4) ◽  
pp. 645-662 ◽  
Author(s):  
Å. Hjalmarson ◽  
K. Ahrén

ABSTRACT The effect of growth hormone (GH) in vitro on the rate of intracellular accumulation of the non-utilizable amino acid α-aminoisobutyric acid (AIB) was studied in the intact rat diaphragm preparation. Bovine or ovine GH (25 μg/ml incubation medium) markedly stimulated the accumulation of AIB-14C by diaphragms from hypophysectomized rats, while there was no or only a very slight effect on diaphragms from normal rats. In diaphragms from rats with the pituitary gland autotransplanted to the kidney capsule GH in vitro stimulated the accumulation of AIB-14C significantly more than in diaphragms from normal rats but significantly less than in diaphragms from hypophysectomized rats. Injections of GH intramuscularly for 4 days to hypophysectomized rats made the diaphragms from these rats less sensitive or completely insensitive to GH in vitro. These results indicate strongly that the relative insensitivity to GH in vitro of diaphragms from normal rats is due to the fact that the muscle tissues from these rats has been exposed to the endogenously secreted GH. The results show that GH can influence the accumulation of AIB-14C in the isolated rat diaphragm in two different ways giving an acute or »stimulatory« effect and a late or »inhibitory« effect, and that it seems to be a time-relationship between these two effects of the hormone.


1968 ◽  
Vol 57 (3_Suppl) ◽  
pp. S19-S35 ◽  
Author(s):  
Å. Hjalmarson

ABSTRACT In vitro addition of bovine growth hormone (GH) to intact hemidiaphragms from hypophysectomized rats has previously been found to produce both an early stimulatory effect lasting for 2—3 hours and a subsequent late inhibitory effect during which the muscle is insensitive to further addition of GH (Hjalmarson 1968). These effects on the accumulation rate of α-aminoisobutyric acid (AIB) and D-xylose have been further studied. In presence of actinomycin D (20 μg/ml) or puromycin (100 μg/ml) the duration of the stimulatory effect of GH (25 μg/ml) was prolonged to last for at least 4—5 hours and the late inhibitory effect was prevented. Similar results were obtained when glucose-free incubation medium was used. Preincubation of the diaphragm at different glucose concentrations (0—5 mg/ml) for 3 hours did not change the GH sensitivity. Addition of insulin at start of incubation could not prevent GH from inducing its late inhibitory effect, while dexamethasone seemed to potentiate this effect of GH. Furthermore, adrenaline was found to decrease the uptake of AIB-14C and D-xylose-14C in the diaphragm, but not to change the sensitivity of the muscle to GH. Preincubation of the diaphragm for 3 hours with puromycin in a concentration of 200 μg/ml markedly decreased the subsequent basal uptake of both AIB-14C and D-xylose-14C, in the presence of puromycin, and abolished the stimulatory effect of GH on the accumulation of AIB-14C. However, the effect of GH on the accumulation of D-xylose-14C was unchanged. The present observations are discussed and evaluated in relation to various mechanisms of GH action proposed to explain the dual nature of the hormone.


1973 ◽  
Vol 74 (1) ◽  
pp. 201-208 ◽  
Author(s):  
D. Maor ◽  
E. Eylan ◽  
P. Alexander

ABSTRACT Ribonuclease activity in thymus and lymph nodes is stimulated by cortisone; insulin increases ribonuclease activity only in the thymus. Growth hormone and theophylline do not cause changes in thymus and lymph nodes ribonuclease levels. Injections of cortisone combined with growth hormone or with theophylline increase the activity more than cortisone alone. Insulin does not enhance the action of cortisone on ribonuclease activity. A synergistic loss in weight of thymus and spleen was found after administration of cortisone in combination with either growth hormone or with theophylline.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1120G-1120
Author(s):  
J. L. Jacobs ◽  
C. T. Stephens

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.


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