Effects of small doses of bovine TSH on serum levels of free and total thyroid hormones, their degradation products, and diiodotyrosine

1985 ◽  
Vol 108 (2) ◽  
pp. 211-216 ◽  
Author(s):  
G. Benker ◽  
C. Splittstößer ◽  
H. Meinhold ◽  
Th. Olbricht ◽  
D. Reinwein

Abstract. Bovine TSH was administered iv to 10 normal volunteers in doses of 2.5, 7.5, 15 and 30 mU/kg. Brisk elevations of serum diiodotyrosine occurred already after the smallest dose (mean, + 183%) while larger doses had only slight additional effects. T3 rose much higher than T4 (+71% compared to +23% after 15 mU bTSH/kg), and free thyroid hormones exhibited changes similar to total T3 and total T4. The mean absolute increase in serum fT3 ranged from 2.03 to 9.04 pmol/l and proved to be an easily measurable parameter for the TSH effect. Dose-response effects were seen for the increases of fT4, fT3 and T3. TBG and rT3 did not change but the degradation product 3,3'-T2 showed large increments of serum levels. There was no correlation between the response of T3 and T4, fT3 and fT4, or diiodotyrosine and any of the other parameters of thyroid function. The interindividual differences in the magnitude of thyroid hormone response to TSH were considerable, and there was no relationship between this response and thyroid volume by ultrasound. We conclude that direct stimulation of the thyroid gland with bTSH in small doses leads to consistent increases of thyroid hormones, especially T3 and fT3, that the response varies between individuals, and that the precursor diiodotyrosine is released together with thyroid hormones.

2021 ◽  
Author(s):  
Fatemeh Eftekharian ◽  
Gholamhossein Ranjbar Omrani ◽  
Mohammad Hossein Dabbaghmanesh ◽  
Reza Sahraei ◽  
Marzieh Bakhshayeshkaram ◽  
...  

Abstract Background The purpose of this study was to determine the association of sonographic parameters with the serum levels of anti-thyroid peroxidase (TPO), anti-thyroglobulin (Tg), and thyroid hormones in patients with Hashimoto's thyroiditis. Methods 149 patients (118 females, 31 males; aged 18–60 years; mean age: 38.60 ± 8.03 years) who were diagnosed with Hashimoto's thyroiditis were enrolled in the study. Blood sample was taken to measure the serum levels of free T3 and T4, thyroid stimulating hormone (TSH), anti-TPO antibody titers, and anti-Tg antibody titers. The thyroid sonography of each patient was classified into one of the five grades by real-time ultrasonography (US) based on echogenicity, thyroid size, and thyroid pattern. We evaluated whether a correlation existed between thyroid characteristics on US and serum levels of thyroid hormones, anti-TPO and anti-Tg. Results Nodular structures were detected in 54 (36.2%) patients (38 micronodular and 16 macros nodular). Echogenicity was recorded as isoechoic in 15 (10.07%) and hypoechoic in 119 (79.87%) subjects. Euthyroid ‎subjects had significantly thicker isthmus than overt and subclinical hypothyroid patients (p = 0.018). Mean serum TSH, anti-Tg and anti-TPO titers was significantly higher in patients with micronodules than those with micronodules and subjects without nodules (P < 0.05). Isthmus thickness had a significant negative correlation with FT4 and FT3 (P = 0.046; r = 0.11& P = 0.017; r = 0.15, respectively). Thyroid autoantibodies had positive significant correlations with different parameters of the thyroid volume (P < 0.05). Conclusions Thyroid’s US findings in addition to serum levels of anti-Tg and anti-TPO titers would be useful in diagnosis and evaluation of the severity and extent of Hashimoto's thyroiditis, but further evaluations are needed. Trial registration: Trial registry identifier IR.SUMS.REC.1395.S161 (2015/11/30).


1994 ◽  
Vol 72 (10) ◽  
pp. 1726-1734 ◽  
Author(s):  
Tim R. Nagy ◽  
Barbara A. Gower ◽  
Milton H. Stetson

The purpose of this study was to examine the effect of photoperiod on serum levels of growth hormone (GH) and thyroid hormones (TH), body mass, and body composition in collared lemmings (Dicrostonyx groenlandicus). Collared lemmings undergo seasonal changes in body mass and body composition, being heavier, but relatively less fat, during the winter months. These physiological changes can be induced in the laboratory by exposure to short photoperiod. The present study tests the hypothesis that photoperiod-mediated changes in GH and TH occur simultaneously with, and therefore may regulate or be permissive to, changes in body mass and body composition. Juvenile (19 d of age) or adult (50 d of age) male collared lemmings reared in long photoperiod (LD), 22 h light (L): 2 h dark (D), either remained in LD or were transferred to short photoperiod (SD), 8 h L: 16 h D. After 1, 2, 3, and 4 weeks (juveniles) or 1 and 3 weeks (adults) of treatment, animals were sacrificed. Serum levels of GH, triiodothyronine, and thyroxine were determined. Carcasses were weighed and analyzed for absolute and relative (analysis of covariance) fat-free dry mass, fat, and water. Exposure to SD resulted in an increase in GH, a decrease in TH, an increase in body mass (due to an absolute increase in all body components), a relative decrease in fat mass, and a relative increase in body water. Results are compatible with the hypothesis that a SD-mediated increase in GH is involved in the greater body mass gain observed in SD animals. Decreases in TH resulting from SD exposure, if associated with a decrease in heat production, may be permissive to mass gain.


1984 ◽  
Vol 104 (4_Supplb) ◽  
pp. S78-S79
Author(s):  
G. BENKER ◽  
C. SPLITTSTÖSSER ◽  
H. MEINHOLD ◽  
TH. OLBRICHT ◽  
D. REINWEIN ◽  
...  

1994 ◽  
Vol 41 (6) ◽  
pp. 717-723
Author(s):  
TAKU KASHIWAI ◽  
HISATO TADA ◽  
HARUO TAMAKI ◽  
YOH HIDAKA ◽  
ERIKO ITO ◽  
...  

1990 ◽  
Vol 29 (01) ◽  
pp. 40-43 ◽  
Author(s):  
W. Langsteger ◽  
P. Költringer ◽  
P. Wakonig ◽  
B. Eber ◽  
M. Mokry ◽  
...  

This case report describes a 38-year-old male who was hospitalized for further clarification of clinically mild hyperthyroidism. His increased total hormone levels, the elevated free thyroid hormones and the elevated basal TSH with blunted response to TRH strongly suggested a pituitary adenoma with inappropriate TSH incretion. Transmission computed tomography showed an intrasellar expansion, 16 mm in diameter. The neoplastic TSH production was confirmed by an elevated alpha-subunit and a raised molar alpha-sub/ATSH ratio. However, T4 distribution on prealbumin (PA, TTR), albumin (A) and thyroxine binding globulin (TBG) showed a clearly increased binding to PA (39%), indicating additional prealbumin-associated hyperthyroxinemia. The absolute values of PA, A and TBG were within the normal range. After removal of the TSH-producing adenoma, basal TSH, the free thyroid hormones and T4 binding to prealbumin returned to normal. Therefore, the prealbumin-associated hyperthyroxinemia had to be interpreted as a transitory phenomenon related to secondary hyperthyroidism (T4 shift from thyroxine binding globulin to prealbumin) rather than a genetically conditioned anomaly of protein binding.


Author(s):  
Bianca Mages ◽  
Thomas Fuhs ◽  
Susanne Aleithe ◽  
Alexandra Blietz ◽  
Constance Hobusch ◽  
...  

AbstractIn the setting of ischemic stroke, the neurofilament subunit NF-L and the microtubule-associated protein MAP2 have proven to be exceptionally ischemia-sensitive elements of the neuronal cytoskeleton. Since alterations of the cytoskeleton have been linked to the transition from reversible to irreversible tissue damage, the present study investigates underlying time- and region-specific alterations of NF-L and MAP2 in different animal models of focal cerebral ischemia. Although NF-L is increasingly established as a clinical stroke biomarker, MAP2 serum measurements after stroke are still lacking. Therefore, the present study further compares serum levels of MAP2 with NF-L in stroke patients. In the applied animal models, MAP2-related immunofluorescence intensities were decreased in ischemic areas, whereas the abundance of NF-L degradation products accounted for an increase of NF-L-related immunofluorescence intensity. Accordingly, Western blot analyses of ischemic areas revealed decreased protein levels of both MAP2 and NF-L. The cytoskeletal alterations are further reflected at an ultrastructural level as indicated by a significant reduction of detectable neurofilaments in cortical axons of ischemia-affected areas. Moreover, atomic force microscopy measurements confirmed altered mechanical properties as indicated by a decreased elastic strength in ischemia-affected tissue. In addition to the results from the animal models, stroke patients exhibited significantly elevated serum levels of MAP2, which increased with infarct size, whereas serum levels of NF-L did not differ significantly. Thus, MAP2 appears to be a more sensitive stroke biomarker than NF-L, especially for early neuronal damage. This perspective is strengthened by the results from the animal models, showing MAP2-related alterations at earlier time points compared to NF-L. The profound ischemia-induced alterations further qualify both cytoskeletal elements as promising targets for neuroprotective therapies.


2021 ◽  
Vol 16 ◽  
Author(s):  
Reihaneh Rezaee ◽  
Masoud Mohebbi ◽  
Mozhgan Afkhamizadeh ◽  
Mohammad Ali Yaghoubi ◽  
Mona Najaf Najafi ◽  
...  

Background and Objective: Subclinical hypothyroidism can potentially develop to overt hypothyroidism. Thyroid hormones have substantial roles in metabolism and glucose homeostasis and thus are closely related to determinant factors of metabolic syndromes, such as obesity and insulin resistance. Osteocalcin is considered a predictor of metabolic conditions in thyroid diseases. This study aimed to investigate the effect of levothyroxine vs. placebo on serum osteocalcin levels in patients with subclinical hypothyroidism. Methods: This randomized clinical trial was performed on 30 patients with subclinical hypothyroidism who were referred to the endocrine clinics of Ghaem and Imam Reza hospitals in Mashhad, Iran. After giving informed consent, patients were randomly divided into intervention (50 µg/day levothyroxine for 2 months) and control (placebo) groups. Serum levels of osteocalcin, thyroid hormones, lipid profile, insulin, and fasting glucose, as well as other clinical and anthropometric data, were measured at baseline and at the end of the study. SPSS was used to analyze the data and P<0.05 was considered significant. Results: Mean age in the intervention and control groups was 35.07 ± 9.94 and 31.30 ± 4.30, respectively (P=0.20). There was no significant difference between osteocalcin levels before and after the intervention in either of the groups (P=0.54). TSH level was significantly decreased in the levothyroxine group after the intervention (P<0.01). T4 level was significantly increased in the intervention group (P=0.02). Conclusion: Levothyroxine had no significant effect on increasing the levels of serum osteocalcin in patients with subclinical hypothyroidism. We have registered the trial in the Iranian registry of clinical trials (IRCT) with the registration code IRCT20171129037677N1.


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