Increased sodium influx and calcium uptake in erythrocytes in hyperthyroidism: role of abnormal membrane lipid levels

Comparing steamed and wine-stewed Rehmanniae Radix in terms of Yin-nourishing effects via metabolomics and microbiome analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Rehmanniae Radix Praeparata (RRP), the processed root of Rehmannia glutinosa, has been widely used to treat Yin deficiency syndrome in traditional Chinese medicine. RRP is available in two forms: processed by steaming with water (SRR) or processed by stewing with yellow rice wine (WRR). Previous work has documented chemical differences in the secondary metabolomes and glycomes of SRR and WRR.

AIM OF THE STUDY

This study aimed to compare SRR and WRR in terms of Yin-nourishing effects via metabolomics and microbiome analysis.

MATERIALS AND METHODS

ICR mice were orally administered with thyroxine for 14 d to induce Yin deficiency. Changes in biochemical indices and histopathology were detected. Serum metabolomics analysis and microbial 16S rRNA sequencing were performed to compare the therapeutic effects and mechanisms between SRR and WRR in treating thyroxine-induced Yin deficiency.

RESULTS

Both SRR and WRR decreased serum T3, T4 and MDA levels, and increased SOD activity. SRR more effectively decreased serum Cr, and ameliorated kidney injury, while WRR showed better regulation on ratio of cAMP/cGMP and serum TSH, and relieved thyroid injury. Both SRR and WRR regulated tyrosine, glycerophospholipid, and linoleic acid metabolism and the citric acid cycle. Additionally, SRR regulated fatty acid metabolism, while WRR influenced alanine, aspartate and glutamate metabolism, and bile acid biosynthesis. SRR significantly enriched the genera Staphylococcus and Bifidobacterium in the gut microbiome, while WRR significantly enriched the genera Akkermansia, Bacteroides and Parabacteroides, and decreased the abundance of Lactobacillus.

CONCLUSIONS

SRR displayed better protective effects on kidney, while WRR showed stronger effects on thyroid in thyroxine-induced Yin deficient mice. These differences might be due to different regulating effects of SRR and WRR on the metabolome and gut microbiota.

Alterations in osmotic fragility of the red blood cells in hypo- and hyperthyroid patients

BACKGROUND

Changes in concentration of thyroid hormones can affect Na+-K+-ATPase number and activity and phospholipid composition of the cell membranes leading to changes in the surface to volume ratio and strength of membrane.

AIM

In this study, the osmotic fragility of the red blood cells from non-treated hypo- and hyperthyroid patients was compared to that of control subjects.

MATERIAL/SUBJECTS AND METHODS

After 3 washings with normal saline, red blood cells were placed in varying concentrations of sodium chloride (Na- Cl) (0-0.9%) and fragility was assessed with colorimetric method; to do this, after the incubation period, tubes were centrifuged and the optical density of the tubes was measured. Hemolysis percentage in tubes was calculated based on 100% hemolysis in the tubes containing no NaCl (0%).

RESULTS

Osmotic fragility of the cells from hyperthyroid patients in 0.45% NaCl was significantly lower than control subjects (74.6%+/-30.2 vs 93.8%+/-9.1, p<0.01). The osmotic fragility of red blood cells in 0.5% concentration of sodium chloride in hyperthyroid patients was significantly lower compared to that of controls (27.8%+/-26.0 vs 63.5%+/-27.5, p<0.001). No significant difference was observed between the osmotic fragility of the hypothyroid patients compared with control subjects.

CONCLUSIONS

Alteration in osmotic fragility is seen in patients with hyperthyroidism; however, anemia reported in hypo- or hyperthyroid patients is not due to high osmotic fragility of red blood cells and other causes need to be investigated.

Effects of triiodothyronine-induced hyperthyroidism on lipid peroxidation, erythrocyte resistance and iron-binding and iron-oxidizing antioxidant properties of plasma in the rabbit

The effect of hyperthyroidism on some oxidative stress parameters is reported. The hyperthyroid state was induced by intraperitoneal injection of triiodothyronine (T3)(10 microg/kg body weight) for 14 days in two groups of female rabbits (3 and 12 months old). The T3 injection caused increase by 1.5-fold to 1.7-fold in T3 serum level, and 2-fold to 3-fold decrease (age-dependent) in body weight gain at the end of experimental period. The induced hyperthyroidism caused a significant increase in the serum concentration of the lipid peroxidation end-product malondialdehyde and lowered erythrocyte resistance to oxidative stress when subjected to the free radical generator 2,2'-azobis(2-amidinopropane) hydrochloride in vitro. The half maximum haemolysis time (HT50) decreased in the both experimental groups of rabbits, by about 12 min in the 3-month-old animals and 27 min in the 12-month-old animals. The study showed for the first time that hyperthyroidism enhances the ability of plasma to protect against iron-binding and iron oxidizing organic radicals. The scavenging property and antioxidant capacity of plasma against iron-binding inorganic radicals also increased. Measurement of erythrocyte resistance to oxidative stress and the protective ability of plasma against oxygen radicals discriminates the thyroid hormone modulatory effects in defence mechanisms against lipid peroxidation.

Impaired Na+,K+ATPase activity in red blood cells in euthyroid women treated with levothyroxine after total thyroidectomy for Graves' disease

In patients suffering from hyperthyroidism dependent on Graves' disease, a reduction in Na+,K+ATPase activity has been demonstrated in red blood cells (RBCs), as well as an inverse correlation between this enzymatic action and free triiodothyronine (FT3) levels. The restoration of normal FT3 values also brings about a normalization of Na+,K+ATPase activity in erythrocytes. These results have made it possible to hypothesize that the thyroid hormones control Na+,K+ATPase activity and that this control is manifested by means of variations in the number of ouabain-binding sites. For this reason, the measurement of the activity of the Na/K pump can be considered as a further indicator of the peripheral effects of thyroid hormones. With a view to assess the relation between the course of treated hyperthyroidism and Na+,K+ATPase activity during antithyroid therapy and after surgical thyroidectomy followed by replacement therapy, we studied 24 patients affected by Graves' disease (group Graves [GG]). They were compared with 24 female Graves' patients who underwent total thyroidectomy for nontoxic and diffuse nodular goiter (NDNG) (group control [GC]) and with 24 normal healthy women (group normal [GN]). When Graves' hyperthyroidism was diagnosed, the Na+,K+ATPase activity in RBCs was impaired in all GG patients. Thionamide treatment restored the normal activity of the Na/K pump, accompanied by normalization of the number of ouabain-binding sites. One hundred eighty days after thyroidectomy, in conditions of clinical and biochemical euthyroidism due to replacement therapy with levothyroxine, the activity of Na+,K+ATPase in RBCs was once again reduced in GG, while appearing normal in GC and GN (1.77 +/- 0.16 mmol Pi h(-1) L(-1) RBCs v 2.09 +/- 0.26 v 2.09 +/- 0.24, P < .05). Different instrumental or biochemical parameters, such as glycemia, serum lipids, ions, serum alkaline phosphatase (AIPh), serum creatine phosphokinase (CPK), blood pressure, and heart rate, were evaluated and appeared normalized in GG and GC 180 days after surgery. We conclude that (1) in patients suffering from Graves' disease, subjected to total thyroidectomy followed by levothyroxine replacement therapy, there is a reduction in the activity of the Na+,K+ATPase on erythrocytes 6 months after the surgical approach; and (2) a similar alteration is not observed in patients subjected to thyroidectomy for NDNG. These findings allow the formulation of the hypothesis that (1) treatment with levothyroxine for 180 days after thyroidectomy in GG is not long enough to restore the normality of all the peripheral indicators of action of the thyroid hormones; and (2) levothyroxine replacement therapy is unable to guarantee euthyroidism in all the tissues in GG (eg, during hematopoiesis in the bone marrow).