Cortisol Secretion Rate in Gonadectomized Female Sockeye Salmon (Oncorhynchus nerka): Effects of Estrogen and Cortisol Treatment

1969 ◽  
Vol 26 (7) ◽  
pp. 1789-1799 ◽  
Author(s):  
Edward M. Donaldson ◽  
Ulf H. M. Fagerlund
Keyword(s):  
Clearance Rate ◽  
Plasma Cortisol ◽  
Sockeye Salmon ◽  
Secretion Rate ◽  
Peanut Oil ◽  
Control Group ◽  
Metabolic Clearance ◽  
Cortisol Secretion ◽  
Metabolic Clearance Rate ◽  
Plasma Cortisol Concentration

Gonadectomized female sockeye salmon (Oncorhynchus nerka) were injected intramuscularly with cortisol, estradiol, estradiol cypionate, or peanut oil for 8 weeks. The metabolic clearance rate of cortisol was determined by the single injection technique and calculated from the formula for a two pool system. The cortisol secretion rate was determined from the metabolic clearance rate and the plasma cortisol concentration.The volume of distribution of cortisol in the inner compartment (V1) and the outer compartment (V2), the metabolic clearance rate (MCR), the resting secretion rate (S), and the resting plasma cortisol concentration were all significantly higher in the estradiol-injected group than in the peanut oil-injected control group, and the plasma cortisol concentration at the end of the experiment was lower. V1, MCR, and S were also significantly higher in the estradiol cypionate-injected group. There were no significant differences between the cortisol-injected group and the peanut oil-injected control group or in the biological half life of cortisol between any groups.There were no significant changes in the red colour of the flesh or in body weight during the experiment. However, the cortisol-injected group did show the largest weight loss.

Effect of Sexual Maturation and Gonadectomy at Sexual Maturity on Cortisol Secretion Rate in Sockeye Salmon (Oncorhynchus nerka)

1970 ◽  
Vol 27 (12) ◽  
pp. 2287-2296 ◽  
Author(s):  
Edward M. Donaldson ◽  
Ulf H. M. Fagerlund
Keyword(s):  
Sexual Maturation ◽  
Clearance Rate ◽  
Sexual Maturity ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Secretion Rate ◽  
Metabolic Clearance ◽  
Cortisol Secretion ◽  
Metabolic Clearance Rate ◽  
Male And Female

Changes in cortisol dynamics in male and female sockeye salmon (Oncorhynchus nerka) have been investigated at various stages during sexual maturation, after spawning, and after gonadectomy just prior to their reaching sexual maturity. The metabolic clearance rate of cortisol was determined by the single injection technique and calculated using the formula for a two-pool system. The volume of distribution of cortisol in the inner pool and the outer pool, metabolic clearance rate, and cortisol secretion rate increased in both male and female salmon during sexual maturation. These changes were reversed in fish that were gonadectomized just before reaching functional maturity and allowed to recuperate for 2 or 8 weeks.There was a decrease in the amount of red carotenoid pigment in the flesh of salmon held in the laboratory during sexual maturation. This loss of pigment was reversed in salmon that were gonadectomized and fed marine zooplankton for 8 weeks.

Méthode de mesure des vitesses d'épuration métabolique et de sécrétion du cortisol chez l'anguille (Anguilla anguilla L.)

1976 ◽  
Vol 54 (3) ◽  
pp. 262-276 ◽  
Author(s):  
Jeanine Leloup-Hatey
Keyword(s):  
Cortisol Level ◽  
Clearance Rate ◽  
Plasma Cortisol ◽  
Specific Activity ◽  
Statistical Treatment ◽  
Plasma Cortisol Level ◽  
Secretion Rate ◽  
European Eel ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate

Classical methods for the analysis of steroid dynamics were adapted to measure the metabolic clearance rate and the secretion rate of cortisol in the European eel using [1,2-3H]cortisol as a tracer.1. Measurements were made whilst the eels were in the steady state; stresses which usually result from anaesthesia and handling were avoided by chronic catheterization of the blood vessels of the swim bladder. In this way, the plasma cortisol level were constant; thus, it was possible to obtain valid measurements of the cortisol secretion rate knowing the metabolic clearance rate and the plasma cortisol level.2. In the eel, cortisol and cortisone together form a 'chemical compartment', derived originally from cortisol secreted by the interrenal gland and subsequently transformed partially into cortisone in the plasma and maintained thenceforth in dynamic reversible equilibrium. Consequently, the metabolic clearance rate of cortisol has been calculated from the known changes in concentration of both [1,2-3H]cortisol and [1,2-3H]cortisone in the plasma deduced from dichloromethane-extractable plasma radioactivity, 72% of which is always attributable to these two steroids from the moment that the radioactivity begins to decline regularly as a function of time (15–30 min after the injection).3. After a single injection of [1,2-3H]cortisol, the interpretation of the disappearance curve by compartmental analysis is complicated by the delay of tracer distribution and by the evident variability in the initial portion of the curve. Disappearance curves have accordingly been analysed in a more rigorous fashion either by integrating the area under each curve which allows one to calculate individually the metabolic clearance rates, or by integrating according to Normand, M., and Fortier, C. (1970. Can. J. Physiol. Pharmacol. 48, 274–281) which allows one statistical treatment of data.4. Estimates of the metabolic clearance rate of cortisol were made in a satisfactory manner by either one of the two integration methods. They were also very similar to estimates obtained by prolonged infusion of [1,2-3H]cortisol to constant specific activity into eels maintained under identical experimental conditions.

CORTISOL SECRETION RATE, GLUCOSE ENTRY RATE AND THE MAMMARY UPTAKE OF CORTISOL AND GLUCOSE DURING PREGNANCY AND LACTATION IN DAIRY COWS

1974 ◽  
Vol 62 (2) ◽  
pp. 371-383 ◽  
Author(s):  
J. Y. F. PATERSON ◽  
J. L. LINZELL
Keyword(s):  
Blood Flow ◽  
Milk Yield ◽  
Plasma Cortisol ◽  
Cortisol Concentration ◽  
Secretion Rate ◽  
Cortisol Secretion ◽  
Entry Rate ◽  
Concentration Difference ◽  
Plasma Cortisol Concentration ◽  
Lactating Cows

SUMMARY Glucose entry rate was measured by primed infusion of [2-3H]glucose, and cortisol secretion rate by infusion of [1,2-3H2]cortisol, in two cows from 142 days before calving to day 287 of lactation. Mammary blood flow and the mammary uptake of glucose and cortisol were also measured. In late pregnancy, cortisol secretion rate was 8·6 ± 3·17 (s.d.) μg/min and plasma cortisol concentration was 1·8 ± 0·52 μg/l. During parturition in one animal the secretion rate was 92 μg/min and plasma cortisol concentration was 15 μg/l. During lactation the secretion rate (26·4 ± 7·14 μg/min) and plasma cortisol concentration (5·6 ± 0·73 μg/l) were significantly greater than in dry cows. The mammary uptake of cortisol was 3 to 4% of the secretion rate in both dry and lactating cows. Glucose entry rate was 5·77 ± 2·250 (s.d.) mg/min/kg0·75 in dry cows and there was no significant mammary uptake of glucose. During lactation the glucose entry increased to 9·45 ± 1·881 mg/min/kg0·75. Mammary uptake of glucose was 3·56 ± 1·949 mg/min/kg0·75. The non-mammary utilization of glucose, glucose entry less mammary uptake, was the same for dry and lactating cows. There was a good correlation between glucose entry and milk yield, and between mammary uptake of glucose and milk yield. Since the mammary arterio-venous glucose concentration difference was relatively constant, it is suggested that the change in mammary blood flow may determine the change in glucose uptake and milk yield.

FOETAL-MATERNAL PRODUCTION AND TRANSFER OF CORTISOL DURING THE LAST DAYS OF GESTATION IN THE GUINEA-PIG

1979 ◽  
Vol 82 (1) ◽  
pp. 43-51 ◽  
Author(s):  
M. DALLE ◽  
P. DELOST
Keyword(s):  
Guinea Pig ◽  
Clearance Rate ◽  
Transfer Rate ◽  
Plasma Cortisol ◽  
Removal Rate ◽  
The Other ◽  
Metabolic Clearance ◽  
Maternal Origin ◽  
Metabolic Clearance Rate ◽  
Secretory Rate

SUMMARY The metabolism and the rate of transfer of cortisol across the placenta in pregnant guinea-pigs and foetuses were studied by constant intravenous infusions of tritium-labelled cortisol. Estimates of endogenous and radioactive plasma cortisol levels were used to calculate the following parameters at four stages before parturition (days 62, 64, 66 and 67; parturition occurring at day 68): metabolic clearance rate; production rate; adrenal secretory rate; transfer rate from mother to foetus and from foetus to mother; irreversible removal rate; the fraction of cortisol derived from the other in the foetal and maternal vascular compartments; the fraction of secreted and recycled cortisol involved in the transfer. The metabolic clearance rate and the rates of production and secretion of cortisol were higher in the mother than in the foetus between days 62 and 67 of gestation. About 90% of the foetal cortisol was of maternal origin. The fraction of maternal cortisol of foetal origin increased in the last days of gestation.

Angiotensin II regulates the metabolism but not the secretion of vasoactive intestinal peptide in the rabbit

1992 ◽  
Vol 83 (5) ◽  
pp. 557-560 ◽  
Author(s):  
R. E. Davis ◽  
G. J. MacDonald ◽  
K. A. Duggan
Keyword(s):  
Angiotensin Ii ◽  
Vasoactive Intestinal Peptide ◽  
Clearance Rate ◽  
Sodium Intake ◽  
Secretion Rate ◽  
Dietary Sodium ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
High Sodium ◽  
Significant Difference

1. We have previously demonstrated that the metabolism and secretion of vasoactive intestinal peptide are affected by both acute and chronic dietary sodium. Sodium concentrations in portal and systemic plasma were unaffected by differing levels of sodium intake or administration of an acute gastric sodium load. We sought, therefore, to determine whether other hormones involved in sodium homoeostasis (such as angiotensin II) might be involved in regulating the metabolism and secretion of vasoactive intestinal peptide. We determined the metabolic clearance rate and theoretical secretion rate of vasoactive intestinal peptide in rabbits on low sodium (high circulating angiotensin II) and high sodium (low circulating angiotensin II) diets with and without simultaneous angiotensin II infusion. 2. The metabolic clearance rate of vasoactive intestinal peptide was significantly higher in rabbits on the high sodium diet during both vehicle control (P<0.01) and angiotensin II (P<0.05) infusion. Angiotensin II infusion decreased the metabolism of vasoactive intestinal peptide in rabbits on both low (P<0.01) and high (P<0.01) sodium diets. 3. Although there was a significant difference in secretion rates between the two dietary groups (P<0.025) under basal conditions, infusion of angiotensin II did not alter the secretion rate significantly in either group. 4. We conclude that angiotensin II regulates the metabolism of vasoactive intestinal peptide in the rabbit, but does not regulate its secretion.

Clearance and production of dehydroepiandrosterone and its sulfate in female baboons.

1978 ◽  
Vol 235 (1) ◽  
pp. E74
Author(s):  
H A Schut ◽  
G J Pepe ◽  
J D Townsley
Keyword(s):  
Body Weight ◽  
Clearance Rate ◽  
Secretion Rate ◽  
Metabolic Clearance ◽  
Serum Concentrations ◽  
Human Beings ◽  
Metabolic Clearance Rate ◽  
Lower Serum ◽  
Relative Production ◽  
Secretion Rates

Serum concentrations of dehydroepiandrosterone (D) are greater and those of D sulfate (DS) are lower in female baboons than in women, suggesting interspecies differences in relative production and catabolism of these steroids. To examine this possibility, the metabolic clearance rate (MCR), interconversion (rho), and production of D and DS were determined in five adult female baboons by constant intravenous infusion of [3H]DS and [14C]D. MCR-D (mean +/- SE) was greater (407 +/- 72.8 1/day; 23.1 +/- 3.4 1/day.kg, P less than 0.01) than MCR-DS (44 +/- 5.7 1/day; 2.5 +/- 0.3 1/day.kg). rho-D leads to DS (mean % +/- SE) was greater (45.4 +/- 3.0, P less than 0.001) than rhoDS leads to D (3.8 +/- 0.6), indicating that the equilibrium favors DS formation. Calculated D production and secretion rates were similar (4.5 and 4.4 microgram/min, respectively), whereas DS production (4.1 microgram/min) was twice its secretion rate (2.1 microgram/min). The large difference between MCR-D and MCR-DS resembles that in human beings. However, when clearance is expressed per kilogram body weight, MCR-D is similar to that in man, but MCR-DS is approximately 15-fold greater in the baboon. It is concluded that compared to values in human beings, the greater MCR-DS in baboons maintains the lower serum DS concentration, whereas the higher serum D levels probably result from the relatively greater secretion rate of D baboons.

SECRETION RATE AND METABOLIC CLEARANCE RATE OF PROLACTIN IN THE RAT DURING MID- AND LATE LACTATION

1979 ◽  
Vol 82 (3) ◽  
pp. 409-415 ◽  
Author(s):  
C. E. GROSVENOR ◽  
N. S. WHITWORTH
Keyword(s):  
Plasma Concentration ◽  
Clearance Rate ◽  
Secretion Rate ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Urethane Anaesthesia ◽  
Plateau Level ◽  
Stimulation Of

The prolactin concentration in the plasma of lactating rats rose less rapidly and attained a significantly lower plateau level in response to suckling on day 20–21 of lactation than it did on day 13–14 of lactation. Neither differences in suckling stimulation of the older pups nor a higher metabolic clearance rate (MCR) of prolactin were implicated in the reduced prolactin concentration seen in the late-lactating rats. The MCR was, in fact, slightly reduced in both conscious and late-lactating rats anaesthetized with urethane when compared with those in mid-lactation. The MCR of prolactin was not significantly altered by urethane anaesthesia in rats on either day of lactation. However, the secretion rate of prolactin, computed from the MCR multiplied by the equilibrum concentration of prolactin during suckling, was considerably reduced (665 to 392 ng/min) from mid- to late lactation. We conclude from these data that the reduced plasma concentration of prolactin in response to suckling in late lactation is the result of an impairment within the prolactin secretory mechanism.

High stocking density affects cortisol secretion and tissue distribution in brook charr, Salvelinus fontinalis

1990 ◽  
Vol 124 (2) ◽  
pp. 311-318 ◽  
Author(s):  
M. M. Vijayan ◽  
J. F. Leatherland
Keyword(s):  
Clearance Rate ◽  
Kidney Tissue ◽  
Stocking Density ◽  
Head Kidney ◽  
Secretion Rate ◽  
Metabolic Clearance ◽  
Low Density ◽  
Cortisol Secretion ◽  
Brook Charr ◽  
Interrenal Cells

ABSTRACT Preparations of head kidney tissue (containing the interrenal cells) from brook charr (Salvelinusfontinalis) which had been held at a high stocking density (120 kg/m3) showed a higher spontaneous secretion rate of cortisol than those from brook charr held at a low stocking density (30 kg/m3). Challenges with ACTH at 5 and 500 mU/ml stimulated the secretion of cortisol in interrenal preparations taken from fish stocked at low density but the high ACTH challenge resulted in a lower cortisol secretion rate. The ACTH-stimulated cortisol secretion by the interrenal cells of brook charr stocked at high density was lower than that of the low density group. There was no difference in the metabolic clearance rate of cortisol in brook charr held at the two stocking densities. The clearance rate of [3H]cortisol from the tissues suggested that in fish held at high stocking density cortisol is rapidly taken up by the liver and subsequently catabolized. Cortisol uptake by the liver in fish held at high stocking density may be an adaptation, which results in altered hepatic metabolic activity. Journal of Endocrinology (1990) 124, 311–318

Participation of tri-iodothyronine and metabolic clearance rate in the inhibition of growth hormone secretion in thyroxine-treated domestic fowl

1990 ◽  
Vol 124 (2) ◽  
pp. 215-223 ◽  
Author(s):  
S. Harvey ◽  
H. Klandorf ◽  
C. G. Scanes
Keyword(s):  
Clearance Rate ◽  
Domestic Fowl ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Secretion Rate ◽  
Bolus Administration ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Gh Secretion ◽  
Inhibition Of Growth

ABSTRACT Surgical thyroidectomy increases basal and TRH-induced GH concentrations in the peripheral plasma of immature domestic fowl. Replacement therapy with thyroxine (T4; 100 μg/kg per day for 7 days, i.m.) suppressed the GH responses to thyroidectomy. Bolus administration of T4 (10 μg/kg, i.m.) to thyroidectomized birds promptly lowered the circulating GH concentrations, which remained suppressed for at least 4 h. Chronic (daily injections for 7 days) or acute (one injection) pretreatment of thyroidectomized birds with iopanoic acid (IOP; 40 mg/bird, i.m.) before the bolus administration of T4 attenuated, but did not prevent, inhibition of circulating GH levels by T4. Administration of IOP (40 mg/bird i.m.) 24 h and immediately before the administration of tri-iodothyronine (T3; 3 μg/kg, i.m.) or T4 (10 μg/kg, i.m.) also failed to suppress thyroidal inhibition of circulating GH concentrations in thyroidectomized birds. Administration of IOP alone had no effect on GH concentrations. Circulating T3 concentrations were not enhanced following the administration of T4 to IOP-treated birds, indicating its inhibition of hepatic monodeiodinase activity. The metabolic clearance rate (MCR) of 125I-labelled chicken GH in the plasma of thyroidectomized fowl was less than that in sham-thyroidectomized birds. Following pretreatment with T4 (100 μg/kg per day for 7 days) sham-thyroidectomized and thyroidectomized birds did not differ significantly in their MCR. The GH secretion rate in thyroidectomized birds was similar to that in sham-thyroidectomized birds and in both groups was markedly reduced following pretreatment with T4. These results demonstrate thyroidal inhibition of circulating GH concentrations in fowl. Both T3 and T4 inhibited GH concentrations and the effect of T4 was not simply due to its role as a T3 prohormone. In the absence of thyroid hormones, the MCR of GH was reduced but its secretion rate was not enhanced. A significant reduction of GH secretion rate occurs in response to exogenous T4, in the absence of any change in GH metabolism. Journal of Endocrinology (1990) 124, 215–223

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