CIRCADIAN AND 30 MINUTES VARIATIONS IN SERUM TSH AND THYROID HORMONES IN NORMAL SUBJECTS

1978 ◽  
Vol 89 (3) ◽  
pp. 659-672 ◽  
Author(s):  
Jørgen Weeke ◽  
Hans Jørgen G. Gundersen
Keyword(s):  
Thyroid Hormones ◽  
Statistical Significance ◽  
Mean Amplitude ◽  
Normal Subjects ◽  
Short Term ◽  
Blood Samples ◽  
Young Males ◽  
Tsh Secretion ◽  
The Mean ◽  
Serum Tsh

ABSTRACT Ten normal young males were investigated in order to examine diurnal and short-term variations in serum TSH and serum thyroid hormones. In five subjects blood samples were obtained every 30 min during a 24 h period of daily life. A synchronous diurnal rhythm was found for free T3 and serum TSH with low levels in the day-time and higher levels at night. The mean increase from day to night was 15 and 140 per cent, respectively. There was a tendency to a similar rhythm in free T4, but the increase of 7 per cent fell short of statistical significance. In the other five men blood samples were obtained every 5 min in a 6 to 7 h period starting within the interval from 19.15 to 22.00 h. A significant regular variation with a cycle-length of half an hour was found in TSH, free T3 and free T4. This rhythm accounted for a significant part of the total variation in the levels of TSH, free T3 and free T4. The mean amplitude of the short-term variation is 13, 15 and 11 per cent of the mean level of the respective hormones. The data suggest a pulsatile release of hormones from the thyroid gland governed by a pulsatile TSH secretion.

Rapid adaptations of serum thyrotrophin, triiodothyronine and reverse triiodothyronine levels to short-term starvation and refeeding

1984 ◽  
Vol 105 (2) ◽  
pp. 194-199 ◽  
Author(s):  
Jean-Noel Hugues ◽  
Albert G. Burger ◽  
A. Eugene Pekary ◽  
Jerome M. Hershman
Keyword(s):  
Serum Cortisol ◽  
Starvation Period ◽  
Short Term ◽  
Mean Values ◽  
Fed State ◽  
Tsh Secretion ◽  
The Mean ◽  
Serum Tsh ◽  
Tsh Levels

Abstract. Nutrition influences thyroid function at the level of TSH secretion, at the level of monodeiodination, and possibly elsewhere. In order to study the effect of starvation on TSH secretion, 8 healthy male volunteers fasted for 30 h and were then refed with 800 kcal. Refeeding was performed at 19.00 h and blood was sampled at 20 min intervals until midnight. Control experiments were performed in the same subjects both when they were normally fed and when the starvation period was prolonged a further 5 h until midnight. Starvation decreased serum TSH levels to below 1 mU/l, and without refeeding the nocturnal peak of the TSH nycthemeral rhythm was abolished. With refeeding serum TSH tended to increase towards midnight and was significantly higher than during starvation. However, the serum TSH levels remained significantly below those at the same time of the day in the absence of a preceding starvation period. Serum T3 levels were significantly lower than in the fed state. The mean values were 1.84 ± 0.03 vs 2.30 ± 0.06 nmol/l (120 ±2 vs 150 ± 4 ng/100 ml, mean ± sem P < 0.01). Refeeding did not result in a measurable change in serum T3 concentration (1.80 ± 0.05 nmol/l; 120 ± 3 ng/100 ml, mean ± sem, n.s.). The contrary was true for rT3 levels which increased in starvation and tended to fall with refeeding, but this decrease was not significant. As glucocorticoids have been implicated in the control of monodeiodination and TSH secretion, serum cortisol levels were also measured. They did not differ during the 3 experimental periods. The results show that short-term starvation and refeeding may be a valuable tool for studying in vivo control of TSH secretion. The results show that short-term starvation and refeeding may be a valuable tool for studying in vivo control of TSH secretion.

scholarly journals Thyroid hormones modulate the endocrine and autocrine/paracrine actions of leptin on thyrotropin secretion

2004 ◽  
Vol 183 (1) ◽  
pp. 243-247 ◽  
Author(s):  
M A L Costa da Veiga ◽  
K de Jesus Oliveira ◽  
F H Curty ◽  
C C Pazos de Moura
Keyword(s):  
Body Weight ◽  
Thyroid Hormones ◽  
Inhibitory Action ◽  
Fold Increase ◽  
Short Term ◽  
Tsh Secretion ◽  
Paracrine Actions ◽  
Serum Tsh

We investigated the influence of hypo- and hyperthyroidism on the ability of leptin to modulate TSH secretion. Two hours after receiving leptin (8 μg leptin/100 g BW; s.c.), hyperthyroid rats (10 μg thyroxine (T4)/100 g body weight (BW) for 5 days) showed a 1.7-fold increase in serum TSH (P<0.05); in hypothyroid rats, leptin had no effect. Hemi-pituitaries of hyperthyroid rats incubated with 10−9 and 10−7M leptin showed reductions in TSH release of 40 and 50% respectively (P<0.05); incubation with 1:2000 and 1:500 dilutions of antiserum against leptin resulted in 3- and 4-fold higher TSH release (P<0.05 and P<0.001 respectively). However, in hypothyroid pituitaries leptin or the antiserum had no effect. The results suggest that the in vivo and in vitro responsiveness of TSH to leptin is abolished in hypothyroidism and is preserved in short-term hyperthyroidism, in comparison to previous reports in euthyroidism. In addition, the inhibitory action of pituitary leptin is enhanced in hyperthyroid glands, which may suggest a role for locally produced leptin in the suppression of TSH release associated with hyperthyroidism.

Elevations in Thyroid-Stimulating Hormone in Normal Subjects after Receiving Short-Term Lithium Carbonate

1988 ◽  
Vol 22 (3) ◽  
pp. 202-204 ◽  
Author(s):  
Merlin V. Nelson ◽  
Vickie Tutag-Lehr ◽  
R. Lee Evans
Keyword(s):  
Lithium Carbonate ◽  
Normal Subjects ◽  
Thyroid Stimulating Hormone ◽  
Short Term ◽  
The Mean ◽  
Early Rise ◽  
State Concentration ◽  
Male Subjects ◽  
Stimulating Hormone

Nine normal, healthy male subjects had significantly elevated thyroid-stimulating hormone (TSH) concentrations while receiving oral lithium carbonate for two weeks. The mean minimum lithium serum concentration was 0.765 mEq/L. The TSH concentrations after 15 days on lithium were significantly correlated to the TSH concentration at baseline. No correlation was found between mean minimum lithium steady-state concentration and TSH concentration after 15 days on lithium. Further research is necessary to determine if a high baseline TSH concentration or an early rise in TSH will predict those patients who will eventually develop hypothyroidism after long-term lithium therapy.

Enzyme immunoassay of free thyroxin in dried blood samples on filter paper.

1985 ◽  
Vol 31 (5) ◽  
pp. 750-753 ◽  
Author(s):  
N Hata ◽  
K Miyai ◽  
M Ito ◽  
Y Endo ◽  
Y Iijimi ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Filter Paper ◽  
Room Temperature ◽  
Normal Subjects ◽  
Blood Samples ◽  
Double Antibody ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Measurable Range

Abstract We describe a double-antibody enzyme immunoassay for determination of free thyroxin (FT4) in dried blood samples on filter paper, with use of a T4-beta-D-galactosidase complex. The measurable range of FT4 concentration in two 3-mm blood discs, each of which contained about 2.7 microL of blood, was 1.9 to 93 ng/L, as determined by comparison with concentrations of FT4 in known serum standards. FT4 in blood samples dried on filter paper was stable for at least four weeks when kept dry at -20 degrees C, room temperature, or 37 degrees C. The mean coefficients of variation were 7.6% (within assay) and 6.4% (between assays). Results for FT4 by this method correlated well with those for serum determined by radioimmunoassay (r = 0.98). The proposed method can be used to differentiate persons with hyper- and hypothyroidism from normal subjects and those with abnormal concentrations of thyroxin-binding globulin. The procedure seems suited for screening studies.

Simplified radioimmunoassay of bradykinin in human plasma.

1980 ◽  
Vol 26 (3) ◽  
pp. 429-432
Author(s):  
P S Verma ◽  
P E Lorenz ◽  
G E Sander
Keyword(s):  
Molecular Mass ◽  
Human Plasma ◽  
Normal Values ◽  
Normal Subjects ◽  
Single Step ◽  
Relative Molecular Mass ◽  
Blood Samples ◽  
Analytical Recovery ◽  
Assay Tube ◽  
The Mean

Abstract A greatly simplified radioimmunoassay for bradykinin in human plasma is described. Current techniques require multiple chromatographic steps or extraction procedures with analytical recoveries of bradykinin of often less than 60%. We present a method in which bradykinin is separated from components of higher relative molecular mass (including kininogens) in a single step, by use of a column of Sephadex G-25 medium (PD-10). The mean analytical recovery of tritiated bradykinin added to plasma is 85.5% (SD, 3.5%). The sensitivity of this radioimmunoassay is 25 pg per assay tube, equivalent to 125 ng per liter of plasma. Twenty to 30 blood samples may be completely processed and assayed within 6 h. As determined with this technique, concentrations of bradykinin in plasma from apparently normal subjects ranged from 2.5 to 5.2 microgram/L (mean 4.2, SD 1.1 microgram/L); these values are consistent with previously reported normal values.

Effects of chronic spinalization on ankle extensor motoneurons. I. Composite monosynaptic Ia EPSPs in four motoneuron pools

1994 ◽  
Vol 71 (4) ◽  
pp. 1452-1467 ◽  
Author(s):  
S. Hochman ◽  
D. A. McCrea
Keyword(s):  
Rise Time ◽  
Statistical Significance ◽  
Mean Amplitude ◽  
Significant Rise ◽  
Medial Gastrocnemius ◽  
Membrane Properties ◽  
Pooled Data ◽  
Extensor Motoneuron ◽  
The Mean ◽  
Stimulation Of

1. We examined the effects of 6-wk chronic spinalization at the L1-L2 level on composite monosynaptic Ia excitatory postsynaptic potentials (EPSPs) recorded in medial gastrocnemius (MG), lateral gastrocnemius (LG), soleus (SOL), and plantaris (PL) motoneurons. Amplitudes, rise times, and half-widths of composite monosynaptic Ia EPSPs evoked by low-strength electrical stimulation of peripheral nerves were measured in barbiturate-anesthetized cats and compared between unlesioned and chronic spinal preparations. 2. The mean amplitude of homonymous composite Ia EPSPs evoked by 1.2 times threshold (1.2T) stimulation and recorded in all four ankle extensor motoneuron pools increased 26% in chronic spinal animals compared with unlesioned controls. There was also an increased incidence of large-amplitude, short-rise time EPSPs. When the same data were separated according to individual motoneuron species, homonymous EPSP amplitudes in MG motoneurons were found to be unchanged. EPSPs recorded in LG motoneurons and evoked by stimulation of the combined LG and SOL nerve were increased by 46%. Mean EPSP amplitudes recorded in both SOL and PL motoneurons were larger after spinalization but statistical significance was only achieved when values from SOL and PL were combined to produce a larger sample size. 3. In LG motoneurons from chronic spinal animals, all EPSPs evoked by 1.2T stimulation of the LGS nerve were > or = 0.5 mV in amplitude. In unlesioned preparations, one fourth of the LG cells had EPSPs that were < or = 0.2 mV. 4. The mean amplitude of heteronymous EPSPs evoked by 2T stimulation of LGS and MG nerves and recorded in MG and LG motoneurons, respectively, doubled in size after chronic spinalization. Because homonymous EPSP amplitudes were unchanged in MG motoneurons, synaptic mechanisms and not passive membrane properties are likely responsible for increased heteronymous EPSP amplitudes in MG. 5. The mean 10-90% rise time of homonymous composite Ia EPSPs in pooled data from all motoneurons decreased 21% in 6-wk chronic spinal animals. Unlike EPSP amplitude, significant rise time decreases were found in all four motoneuron pools. Compared with the other motoneuron species, the mean homonymous rise time recorded in MG motoneurons was shortest and decreased the least in chronic spinal animals. Rise times of heteronymous Ia EPSPs in MG and LG motoneurons also decreased. The maximum rate of rise of homonymous EPSPs increased in all four motoneuron species. 6. The mean half-widths of Ia composite EPSPs decreased in 6-wk spinalized preparations in all motoneuron species.(ABSTRACT TRUNCATED AT 400 WORDS)

An investigation of LH pulsatility in burned men by bioassay and radioimmunoassay

1992 ◽  
Vol 126 (5) ◽  
pp. 404-409 ◽  
Author(s):  
CG Semple ◽  
R Mitchell ◽  
S Hollis ◽  
WR Robertson
Keyword(s):  
Biological Activity ◽  
Serum Testosterone ◽  
Normal Subjects ◽  
Published Data ◽  
Blood Samples ◽  
Testosterone Concentration ◽  
Lh Pulsatility ◽  
Pulse Peak ◽  
The Mean ◽  
Normal Men

LH pulsatility studies were performed in six burned patients by removing blood samples at 10 min intervals over a 6 h period. All samples were assayed for LH by bioassay (B-LH), LH by radioimmunoassay (I-LH) and testosterone. Mean serum testosterone concentrations of the burned patients were low (6.7±1.6 nmol/l). I-LH levels were lower than B-LH in all samples. Frequency of bioactive or immunoreactive pulses as well as mean B-LH and I-LH concentrations were similar to previously published data from normal men examined in the same laboratory. The mean biological activity of LH (expressed as the ratio of B-LH to I-LH, the B:I ratio) was lower in burned subjects (1.9±0.1) than previously reported in normal men. The B:I ratios of burned men were lower (p <0.01) at pulse peaks than at nadirs (1.8±0.1 vs 2.0±0.1) and an increase in serum testosterone concentration did not follow an LH peak. Serum testosterone concentrations did not cross-correlate with B-LH or I-LH. This contrasts with the findings in normal subjects where the B:I ratios have been found to be higher at pulse peaks than at nadirs and an increase in serum testosterone concentration follows a pulse peak and serum testosterone cross-correlates with B-LH and I-LH. LH secreted in a pulse peak in normal men may contain a particularly biologically potent form of the molecule but this may not be the case in burned men.

THE EXCRETION OF C-16 OXYGENATED NEUTRAL STEROID SULPHATES AND DEHYDROEPIANDROSTERONE SULPHATE IN NORMAL PREGNANCY, AND A COMPARISON WITH THEIR EXCRETION BY ENDOCRINOLOGICALLY NORMAL SUBJECTS OF BOTH SEXES

1973 ◽  
Vol 72 (3) ◽  
pp. 587-603 ◽  
Author(s):  
J. Seth ◽  
G. W. Pennington
Keyword(s):  
Statistical Significance ◽  
Normal Subjects ◽  
Normal Pregnancy ◽  
Maternal Circulation ◽  
Pregnant Females ◽  
Neutral Steroid ◽  
Usual Criterion ◽  
The Mean ◽  
The Difference ◽  
Normal Males

ABSTRACT The respective mean 24 h urinary excretions of sulphoconjugated 16α-hydroxydehydroepiandrosterone, 16-oxo-androstenediol, and dehydroepiandrosterone were found to be 1040, 230, and 668 μg/24 h for normal males, and 621, 209, and 304 μg/24 h for normal non-pregnant females. None of the differences in mean steroid excretions between males and non-pregnant females was statistically significant according to the usual criterion for significance (P < 0.05). The mean excretions of sulphoconjugated 16α-hydroxydehydroepiandrosterone, 16-oxo-androstenediol and dehydroepiandrosterone between the 10th week of normal pregnancy and term were 1300, 505 and 226 μg/24 h respectively. No significant trend in the excretions of these neutral steroid sulphates between the 10th week of pregnancy and term could be detected. The increased excretion of both C-16 oxygenated steroid sulphates in pregnancy was highly significant (P < 0.001). In contrast, the statistical significance of the difference in excretion of dehydroepiandrosterone sulphate between pregnant and non-pregnant females could not be established. There did not appear to be any relationship between the excretion of 16α-hydroxydehydroepiandrosterone sulphate and oestriol in normal pregnancy. The results are considered to be consistent with a limited transplacental passage of neutral steroids from the foetoplacental to maternal circulation.

scholarly journals Profiling of Chromosomal Complement in Nandidurga Goats of Karnataka

2021 ◽  
Author(s):  
Basavraj Inamdar ◽  
R. Nagaraja ◽  
H.M. Yathish ◽  
S. Naveen Kumar ◽  
G.S. Naveen Kumar ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Y Chromosome ◽  
X Chromosome ◽  
Relative Length ◽  
Lymphocyte Culture ◽  
Short Term ◽  
Blood Samples ◽  
Chromosomal Complement ◽  
Morphological Index ◽  
The Mean

Background: To characterize the chromosomal complement of Nandidurga goats. Methods: Blood samples for short term lymphocyte culture were collected from 5 bucks and 5 does from its breeding tract and then mitotic chromosomal spreads were accomplished. Result: The diploid chromosome number was found to be 60, consisting of 58 acrocentric autosomes and 2 sex chromosomes (X and Y). The X chromosome was found to be the longest acrocentric and Y chromosome was found to be sub metacentric. The mean mitotic drive was 64.5±2.01 and 63.15±1.30 percent in bucks and does, respectively. The mean relative length of autosomes varied from 2.08±0.24 to 4.81±0.12 in does and 2.09±0.09 to 4.70±0.11in bucks. The relative length of X chromosome in does was 5.14±0.17 and that in bucks was 4.92±0.21, whereas Y chromosome had a relative length of 1.99±0.20. The mean Arms Ratio, Centromeric Index and Morphological Index were 2.47, 31.62 and 396.14, respectively. This cytogenetic analysis indicates the normal chromosomal complement in the studied Nandidurga goats.

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