Steroid Transformations by Corpuscles of Stannius of the Atlantic Cod (Gadus morhua L.)

1966 ◽  
Vol 23 (8) ◽  
pp. 1249-1255 ◽  
Author(s):  
D. R. Idler ◽  
H. C. Freeman
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Hydroxysteroid Dehydrogenase ◽  
Corpuscles Of Stannius

Corpuscles of Stannius tissue of Atlantic cod (Gadus morhua L.) transformed [4-14C] pregnenolone to progesterone and [4-14C] progesterone to 11-desoxycorticosterone in vitro. These results establish the presence of 3β-hydroxysteroid dehydrogenase, Δ5-3-ketoisomerase and 21-hydroxylase. Transformation of the 14C-steroid precursors to several as yet unidentified substances also occurred.

scholarly journals 20β-hydroxysteroid dehydrogenase and CYP19A1 are differentially expressed during maturation in Atlantic cod (Gadus morhua)

2007 ◽  
Vol 39 (4) ◽  
pp. 319-328 ◽  
Author(s):  
C Mittelholzer ◽  
E Andersson ◽  
D Consten ◽  
T Hirai ◽  
Y Nagahama ◽  
...  
Keyword(s):  
Real Time ◽  
Quantitative Pcr ◽  
18S Rrna ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Elongation Factor ◽  
Hydroxysteroid Dehydrogenase ◽  
Elongation Factor 1Α ◽  
Eukaryotic Elongation Factor ◽  
Pcr Assays

AbstractIn order to better quantify the molecular mechanisms regulating final oocyte maturation and spawning, complete coding sequences with partially or fully untranslated regions for the steroidogenic enzymes, cytochrome P450 aromatase and 20β-hydroxysteroid dehydrogenase, were cloned from ovaries of Atlantic cod (Gadus morhua). The nucleotide and amino acid sequences showed high homologies with the corresponding sequences of other fish species, and conserved features important for functionality were identified in both predicted proteins. The sequences of the corresponding genomic loci were also determined, allowing the design of mRNA-specific quantitative PCR assays. As a reference gene for the real-time RT-PCR assays, eukaryotic elongation factor 1α was chosen, and the mRNA as well as the genomic sequence was determined. In addition, a real-time quantitative PCR assay for the 18S rRNA was adapted to be used in cod. Analysis of immature and maturing female cod from July to January respectively showed that the enzyme genes showed the expected quantitative changes associated with physiological regulation. However, mRNA for eukaryotic elongation factor 1α, and to a lesser extent even 18S rRNA, showed variable expression in these samples as well. To find accurate standards for real-time PCR in such a dynamic organ as the cod ovary is not an easy task, and several possible solutions are discussed.

Inhibitory effects of Atlantic cod (Gadus morhua) peptides on RANKL-induced osteoclastogenesis in vitro and osteoporosis in ovariectomized mice

2022 ◽  
Author(s):  
Meilian Yang ◽  
Di Wu ◽  
Shuzhen Cheng ◽  
Yu Dong ◽  
Chao Wu ◽  
...  
Keyword(s):  
Nutritional Value ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Economic Value ◽  
Underlying Mechanism ◽  
Inhibitory Effects ◽  
Ovariectomized Mice ◽  
The World ◽  
The Impact

Atlantic cod (Gadus morhua) is one of the most important fishes in the world with high nutritional value and economic value. However, the impact and underlying mechanism of the G....

scholarly journals Sex steroids differentially regulate fshb, lhb and gnrhr expression in Atlantic cod (Gadus morhua)

Reproduction ◽  
2017 ◽  
Vol 154 (5) ◽  
pp. 581-594 ◽  
Author(s):  
Kristine von Krogh ◽  
Gunnveig Toft Bjørndal ◽  
Rasoul Nourizadeh-Lillabadi ◽  
Kjetil Hodne ◽  
Erik Ropstad ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Viability ◽  
Gadus Morhua ◽  
Hormone Receptors ◽  
Atlantic Cod ◽  
Membrane Integrity ◽  
Gonad Maturation ◽  
Maturity Stage ◽  
Its Gene

Depending on the stage of gonad maturation, as well as other factors, gonadal steroids can exert either a positive or negative feedback at the brain and pituitary level. While this has been demonstrated in many teleost species, little is known about the nature of steroid feedback in Gadiform fish. Using an optimized in vitro model system of the Atlantic cod pituitary, the present study investigated the potential effects of two physiologically relevant doses of estradiol, testosterone (TS) or dihydrotestosterone (DHTS) on cell viability and gene expression of gonadotropin subunits (fshb/lhb) and two suggested reproduction-relevant gonadotropin-releasing hormone receptors (gnrhr1b/gnrhr2a) during three stages of sexual maturity. In general, all steroids stimulated cell viability in terms of metabolic activity and membrane integrity. Furthermore, all steroids affected fshb expression, with the effect depending on both the specific steroid, dose and maturity status. Conversely, only DHTS exposure affected lhb levels, and this occurred only during the spawning season. Using single-cell qPCR, co-transcription of gnrhr1b and gnrhr2a was confirmed to both fshb- and lhb- expressing gonadotropes, with gnrhr2a being the most prominently expressed isoform. While steroid exposure had no effect on gnrhr1b expression, all steroids affected gnrhr2a transcript levels in at least one maturity stage. These and previous results from our group point to Gnrhr2a as the main modulator of gonadotropin regulation in cod and that regulation of its gene expression level might function as a direct mechanism for steroid feedback at the pituitary level.

Involvement of nitric oxide in inhibitory innervation of urinary bladder of Atlantic cod, Gadus morhua

1996 ◽  
Vol 270 (6) ◽  
pp. R1380-R1385
Author(s):  
C. Olsson ◽  
S. Holmgren
Keyword(s):  
Nitric Oxide ◽  
Urinary Bladder ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Maximal Effect ◽  
No Donor ◽  
Beta Adrenoceptor ◽  
Adrenoceptor Antagonist ◽  
Ly 83583

The aim of this study was to investigate the involvement of nitric oxide (NO) in the nonadrenergic, noncholinergic (NANC) relaxation of the urinary bladder of the Atlantic cod, Gadus morhua. NADPH diaphorase-reactive nerve cells, presumed to be able to produce NO, were found in the vesicular nerve. The cells occurred alone and in ganglia together with stained and unstained cells. The effect of inhibitors of NO synthesis on the relaxation was examined in vitro in isolated muscle preparations. NG-nitro-L-arginine methyl ester (10(-4) M) and NG-nitro-L-arginine (L-NNA; 10(-4) M) decreased the electrically induced relaxation to 32 +/- 6 (n = 8) and 28 +/- 6% (n = 8) of the control, respectively. L-Arginine (10(-3) M) increased the relaxation to 152 +/- 24% (n = 8), without affecting the inhibition by L-NNA. The beta-adrenoceptor antagonist propranolol together with L-arginine analogues abolished the relaxation in 7 of 11 preparations. The NO donor sodium nitroprusside (NaNP) caused a concentration-dependent relaxation of the bladder, with a maximal effect obtained at 10(-4) M. LY-83583 (10(-5) M), a guanylate cyclase inhibitor, decreased both the electrically (n = 8) and the NaNP (10(-6) M, n = 9)-induced relaxation to 69 +/- 5 and 20 +/- 4% of the control, respectively. Together these findings suggest that NO is involved in the NANC regulation of the motility of the urinary bladder of the Atlantic cod.

scholarly journals Kinetics of Calcium Fluxes Across the Intestinal Mucosa of the Marine Teleost, Gadus Morhua, Measured Using an In Vitro Perfusion Method

1988 ◽  
Vol 140 (1) ◽  
pp. 171-186 ◽  
Author(s):  
KRISTINA SUNDELL ◽  
BJÖRN THRANDUR BJÖRNSSON
Keyword(s):  
Intestinal Mucosa ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Calcium Influx ◽  
Calcium Excretion ◽  
Passive Component ◽  
Marine Teleost ◽  
Atpase Inhibitor

An in vitro technique for perfusion of the intestinal vasculature and lumen was developed and used to measure calcium (Ca2+) fluxes across the intestinal mucosa of the marine teleost, the Atlantic cod (Gadus morhua). Saturable and nonsaturable components of the calcium influx and efflux were determined. The calcium influx had one passive component and one saturable component, following Michaelis-Menten kinetics with Km = 8.41mmoll−1 and Vmax = 0.604μmol Ca2+ kg−1 h−1. At physiological Ca2+ concentrations in the vascular ([Ca2+] = l.9mmoll−1) and luminal ([Ca2+] =14.9mmoll−1) perfusion fluids, the saturable component amounted to 60% of the Ca2+ influx. The high-affinity Ca2+-ATPase inhibitor chlorpromazine (CP, 10−4moll−1) antagonized 45% of the Ca2+ influx. The Ca2+ efflux across the intestinal mucosa of the cod was a saturable process, following Michaelis-Menten kinetics with Km =6.15mmoll−1 and Vmax =3.79μmol Ca2+ kg−1h−1, but insensitive to CP (l0−5moll−1). The Ca2+ efflux was l.22μumol Ca2+ kg−1 h−1, representing about 20% of the total calcium excretion and about 50% of the extrarenal excretion of the Atlantic cod in vivo.

Scavenger-receptor-mediated endocytosis in endocardial endothelial cells of Atlantic cod Gadus morhua.

1998 ◽  
Vol 201 (11) ◽  
pp. 1707-1718 ◽  
Author(s):  
K K Sørensen ◽  
J Melkko ◽  
B Smedsrød
Keyword(s):  
Endothelial Cells ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Scavenger Receptor ◽  
Scavenger Receptors ◽  
Type I ◽  
Receptor Ligands ◽  
Endocardial Endothelial Cells ◽  
Scavenger Receptor Ligands

Scavenger receptors are multifunctional integral membrane proteins that mediate the endocytosis of many different macromolecular polyanions and also participate in host defence reactions and cell adherance. In Atlantic cod (Gadus morhua L.), two intravenously injected scavenger receptor ligands, [125I]tyramine-cellobiose-labelled formaldehyde-treated serum albumin (125I-TC-FSA) and 125I-labelled N-terminal propeptide of type I procollagen (125I-PINP), distributed mainly to the heart. Cellular uptake was visualized by injections of fluorescently labelled FSA (FITC-FSA), which was recovered in discrete vesicles in endocardial endothelial cells of both heart chambers. Studies in vitro showed that radioiodinated FSA and PINP were endocytosed and degraded very efficiently by cultured atrial endocardial endothelial cells. Moreover, uptake of 125I-FSA was Ca2+-independent. Out of a range of unlabelled ligands, only the scavenger receptor ligands FITC-FSA, polyinosinic acid and, to a varying extent, FSA, acetylated low-density lipoprotein (AcLDL) and PINP, were able to compete with radioiodinated FSA, PINP or AcLDL for uptake in isolated endocardial cells. From our findings, we conclude that the endocardial endothelial cells are major carriers of scavenger receptors in cod. In addition, our results strengthen the hypothesis that these cells in cod play the same important function as that established for the scavenger endothelial cells of the mammalian liver.

The importance of nervous and humoral mechanisms in the control of cardiac performance in the Atlantic cod Gadus morhua at rest and during non-exhaustive exercise

1988 ◽  
Vol 137 (1) ◽  
pp. 287-301 ◽  
Author(s):  
M. Axelsson
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Gadus Morhua ◽  
Positive Inotropic Effect ◽  
Atlantic Cod ◽  
Inotropic Effect ◽  
Response Curves

The nervous regulation of heart rate and stroke volume in the Atlantic cod Gadus morhua was investigated both in vivo, during rest and exercise, and in vitro. The cholinergic and adrenergic influences on the heart were estimated in experiments with injections of atropine and sotalol. At rest the cholinergic and adrenergic tonus on the heart were 38% and 21%, respectively (ratio 1.81:1). At the end of an exercise period, the cholinergic tonus had decreased to 15% but the adrenergic tonus had increased to 28% (ratio 0.54:1). The results suggest that variation of the cholinergic tonus on the heart is a major factor in the regulation of the heart rate. In one group of fish, cardiac output was also measured, allowing calculation of stroke volume. Cardiac output increased significantly during exercise, and this effect persisted in the presence of both atropine and sotalol, although the increase in heart rate was reduced or abolished. The persisting increase in cardiac output during exercise is due to an increase in stroke volume, reflecting a Starling relationship. In the presence of the adrenergic neurone-blocking agent bretylium, a positive inotropic effect on isolated, paced atrial and ventricular strips was observed. In the atrial preparations the effect persisted after 24 h. The effect was prevented by pretreatment with sotalol or cocaine, but potentiated by phentolamine pretreatment. This shows that bretylium exerts its neurone-blocking action after being taken up into the adrenergic nerves, and suggests that the positive inotropic effect of bretylium observed in vivo is due to release of endogenous catecholamines. The concentration-response curves for adrenaline on isolated spontaneously beating atrial preparations showed that the concentrations of catecholamines necessary to produce appreciable effects on the heart are higher than the concentrations found in cod plasma during ‘stress’ situations (handling and exhaustive swimming).

Sign in / Sign up

Export Citation Format

Share Document