scholarly journals Salinity preference of silvering Japanese eel Anguilla japonica: evidence from pituitary prolactin mRNA levels and otolith Sr:Ca ratios

2003 ◽  
Vol 259 ◽  
pp. 253-261 ◽  
Author(s):  
YS Han ◽  
JYL Yu ◽  
IC Liao ◽  
WN Tzeng
Keyword(s):  
Anguilla Japonica ◽  
Japanese Eel ◽  
Mrna Levels ◽  
Otolith Sr:Ca Ratios ◽  
Salinity Preference ◽  
Sr:Ca Ratios ◽  
Pituitary Prolactin ◽  
Prolactin Mrna

scholarly journals Changes in mRNA levels of vitellogenin 1 and 2 during artificial maturation in Japanese eel, Anguilla japonica

2002 ◽  
Vol 68 (sup1) ◽  
pp. 971-972
Author(s):  
HAJIME MATSUBARA ◽  
HIROMI OKUMURA ◽  
TOMOKO OMORI ◽  
HIROYOSHI OHHASHI ◽  
YOKO KOEDA ◽  
...  
Keyword(s):  
Anguilla Japonica ◽  
Japanese Eel ◽  
Mrna Levels ◽  
Artificial Maturation

Changes in mRNA levels of ovarian steroidogenic enzymes during artificial maturation of Japanese eel Anguilla japonica

2003 ◽  
Vol 69 (5) ◽  
pp. 979-988 ◽  
Author(s):  
Hajime MATSUBARA ◽  
Yukinori KAZETO ◽  
Shigeho IJIRI ◽  
Toshiaki HIRAI ◽  
Shinji ADACHI ◽  
...  
Keyword(s):  
Anguilla Japonica ◽  
Japanese Eel ◽  
Mrna Levels ◽  
Steroidogenic Enzymes ◽  
Artificial Maturation

Regulation of LH subunit mRNA levels by gonadal hormones in female rats

1988 ◽  
Vol 1 (1) ◽  
pp. 49-60 ◽  
Author(s):  
S. D. Abbot ◽  
K. Docherty ◽  
R. N. Clayton
Keyword(s):  
Gene Expression ◽  
Physiological Role ◽  
Gonadal Hormones ◽  
Ovariectomized Rats ◽  
Mrna Levels ◽  
Subunit Gene ◽  
Progesterone Treatment ◽  
Serum Lh ◽  
Pituitary Prolactin ◽  
Prolactin Mrna

ABSTRACT To determine the physiological role of the ovaries in regulation of LH subunit gene expression, levels of cytoplasmic mRNA were measured in a cDNA-RNA dot-blot hybridization assay. An increase (twofold) in α mRNA was first detected 8 days after ovariectomy and then remained stable for 4 weeks. In contrast, LH-β mRNA increased by 60–79% within 12 h of removing the ovaries and then rose progressively to six times the intact values at 3 and 4 weeks. Increases in LH-β mRNA were always greater than those of α mRNA. Oestradiol, and oestradiol plus progesterone, but not progesterone alone, prevented the rise in α and LH-β mRNA 10 days after ovariectomy. Three days after ovariectomy, α mRNA, but not LH-β mRNA, was suppressed to below intact control values by oestradiol and oestradiol plus progesterone, indicating greater sensitivity of α mRNA to oestradiol inhibition at this stage. A single injection of oestradiol (1 μg s.c.) to rats ovariectomized 14 days previously transiently suppressed α and LH-β mRNA levels and serum LH concentrations in parallel for 1–8 h, after which high preinjection values were restored. However, pituitary LH content remained suppressed after LH mRNA levels had returned to the control values of ovariectomized rats. In most instances there was a qualitative positive correlation between changes in α and LH-β mRNA, pituitary LH content and serum LH concentrations. LH content reflected LH-β mRNA changes more closely than those of α mRNA. However, in oestradiol-treated rats ovariectomized 10 days previously, LH content remained increased despite normalization of the LH-β and α mRNA levels, suggesting differential sensitivity to oestradiol of the gene expression and translational processes. Thus divergence of pre- and post-translational regulation of LH biosynthesis was demonstrated. These results imply an important physiological role for female sex hormones in the control of LH gene expression and LH biosynthesis. Prolactin mRNA fell by 30–50% for the first 2 weeks after ovariectomy, but by 3 and 4 weeks values were similar to those of intact controls. Serum and pituitary prolactin levels were reduced by 50% or more at all time-points, despite normalization of mRNA. Treatment of ovariectomized rats for 10 days with oestradiol and progesterone, either alone or combined, reversed the fall in prolactin mRNA and serum and pituitary prolactin levels. These changes in prolactin gene expression and synthesis were opposite to those of LH subunits in response to the same in-vivo hormone manipulations. Growth hormone mRNA levels were unchanged by ovariectomy, oestradiol or progesterone treatment. Levels of TSH-β mRNA increased slightly (maximum up to 50%) after ovariectomy, but were unaltered by oestradiol and progesterone treatment for 10 days. These results support the view that α mRNA changes, resulting from ovariectomy, oestradiol and progesterone treatment, occur in gonadotrophs and not thyrotrophs, which also express the α subunit gene.

Regulation of LH subunit and prolactin mRNA by gonadal hormones in mice

1989 ◽  
Vol 2 (3) ◽  
pp. 213-224 ◽  
Author(s):  
G. Saade ◽  
D. R. London ◽  
M. R. A. Lalloz ◽  
R. N. Clayton
Keyword(s):  
Gonadal Hormones ◽  
Female Rats ◽  
Pituitary Hormone ◽  
Mrna Levels ◽  
Α Subunit ◽  
Subunit Mrna ◽  
Serum Lh ◽  
Prolactin Content ◽  
Pituitary Prolactin ◽  
Prolactin Mrna

ABSTRACT The effect of castration and gonadal steroid replacement on the concentrations of LH-β and α subunit and prolactin mRNA was examined in mice. Mouse LH-β, α and prolactin mRNAs were approximately 0·8, 0·7 and 1·1 kb in size respectively. After ovariectomy, LH-β mRNA levels increased 2- to 2·5-fold, while α mRNA levels increased 2·5-fold 6 and 10 days after ovariectomy. Serum LH rose after 2 days to reach six times control values at 10 days. Pituitary LH content doubled by 8 days after ovariectomy. Prolactin mRNA levels decreased to 50–60% of control at 3, 6, 8 and 10 days after ovariectomy and parallelled the fall in serum prolaction. Pituitary prolactin content fell more slowly, to 50% of intact control values by 10 days. The increase in both LH-β and α subunit mRNA, and decrease in prolactin mRNA, and serum and pituitary hormone changes, after ovariectomy were prevented by oestradiol or oestradiol plus progesterone replacement. Levels of LH-β mRNA increased more quickly in male than in female mice, theearliest change being seen 24 h after orchidectomy. Maximum values (two- to threefold) were found on day 6 after orchidectomy. Concentrations of α mRNA increased by 12 h to between 2 and 2·5 times control from 3 to 10 days after orchidectomy. Serum LH doubled by 12 h and was three to five times greater than control values up to 10 days. Pituitary LH content fell by 48 h before gradually increasing to intact values after 10 days. Prolactin mRNA levels decreased progressively from 2 days after orchidectomy, and this decrease was preceded by a fall in serum and pituitary prolactin which remained low throughout the experiment. Testosterone treatment attenuated the rise in α mRNA, prevented the rise in LH-β mRNA and serum LH and partially restored the decrease in prolactin mRNA seen after orchidectomy. We conclude that in mice, as in rats and ewes, both LH-β and α subunit mRNAs are negatively regulated by gonadal steroids, whereas prolactin mRNA is positively regulated, although there are temporal differences in patterns of mRNA responses between males and females. By comparison with female rats the rise in LH-β mRNA after ovariectomy was slower in mice. Moreover, the discordant changes in pituitary LH content and LH subunit mRNAs seen in mice after castration were not observed in rats. Furthermore, pituitary prolactin and prolactin mRNA do not fall after orchidectomy of rats. The modest (50%) increase of LH-β mRNA after castration of mice suggests that an increase in mRNA is not necessarily required for increased LH production.

Cloning of a toad prolactin cDNA: expression of prolactin mRNA in larval and adult pituitaries

1993 ◽  
Vol 11 (3) ◽  
pp. 343-349 ◽  
Author(s):  
N Takahashi ◽  
K Yamamoto ◽  
S Kikuyama
Keyword(s):  
Amino Acid ◽  
Sea Turtle ◽  
Sequencing Analysis ◽  
Mrna Levels ◽  
Amino Acid Residues ◽  
Polymerase Chain ◽  
Prolactin Synthesis ◽  
Pituitary Prolactin ◽  
Prolactin Mrna ◽  
Reaction Sequencing

ABSTRACT A toad (Bufo japonicus) prolactin cDNA was specifically amplified from cDNAs constructed from the total RNA of adenohypophyses, employing the DNA polymerase chain reaction. Sequencing analysis revealed that the cDNA clone thus obtained was 602 bp in length, and encoded the C-terminal 134 amino acid residues of the toad prolactin molecule. The length of the toad prolactin mRNA was estimated to be about 1·0 kb by Northern blot analysis. The partial amino acid sequence deduced from the nucleotide sequence showed the following homologies between toad prolactin and the prolactins of other vertebrates: 69% with man, 80% with chicken, 81% with sea turtle, 91% with bullfrog and 38% with salmon. Using the cDNA as a probe, developmental and seasonal changes in prolactin mRNA levels in the pituitaries of toads were studied. Prolactin mRNA in the pituitary rose as metamorphosis progressed and declined at the end of metamorphosis. During the breeding season the pituitary content of prolactin mRNA was relatively high. This finding suggests that the increases in plasma and pituitary prolactin levels in larvae at metamorphic climax and in adults that remain in or migrate into water, as reported previously, accompany the increase in prolactin synthesis.

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