[Morphological and biochemical characterization during seed development of Notopterygium incisum].

This study aimed to examine the morphological, physiological, and biochemical alterations occurring in Notopterygium incisum seeds throughout their developmental stages, with the objective of establishing a theoretical foundation for the cultivation of superior quality seeds. The experimental materials utilized in this study were the seeds of N. incisum at various stages of development following anthesis. Through the employment of morphological observation and plant physiology techniques, the external morphology, nutrients, enzyme activity, and endogenous hormones of the seeds were assessed. The results revealed a transition in seed coat color from light green to brown during the growth and development of N. incisum seeds. Additionally, as the seeds matured, a decrease in water content was observed. Conversely, starch content exhibited a progressive increase, while sucrose content displayed fluctuations. At 7 days after anthesis, the soluble sugar content attained its highest level of 4.52 mg·g~(-1), whereas the soluble protein content reached its maximum of 6.00 mg·g~(-1) at 14 days after anthesis and its minimum of 4.94 mg·g~(-1) at 42 days after anthesis. The activity of superoxide dismutase(SOD) exhibited an initial increase, followed by a decrease, and eventually reached a stable state. Conversely, the activities of catalase(CAT) and peroxidase(POD) demonstrated a decrease initially, followed by an increase, and then another decrease. The levels of the four endogenous hormones, namely gibberellin(GA_3), zeatin riboside(ZR), auxin(IAA), and abscisic acid(ABA), in the seeds displayed significant variations, with IAA and ABA exhibiting considerably higher levels compared to the other hormones. The levels of plant growth-promoting hormones, represented by IAA, generally displayed a pattern of initial increase followed by a subsequent decrease during seed development, while the plant growth-inhibiting hormone ABA showed the opposite trend. The findings indicate that the alterations in nutrient composition, antioxidant enzyme activity, and endogenous hormone levels vary throughout the maturation process of N. incisum seeds. These observations hold relevance for the cultivation of N. incisum seeds.

[Effect of intercropping with Vicia faba on secondary metabolites and rhizosphere soil microbial diversity of Notopterygium incisum].

Rhizosphere soil microbial community and its diversity are important for the structure and functions of medicinal plant ecosystem. In this study, based on high-throughput sequencing, rhizosphere soil microbial diversity, and yield and quality of rhizome and root of Notopterygium incisum cultivated alone(control, CK) and intercropped with Vicia faba(QH) were analyzed, which is expected to lay a basis for optimization of the cultivation mode and ecological production of N. incisum. RESULTS:: showed that the rhizosphere soil bacteria of N. incisum were dominated by Proteobacteria and Bacteroides, with the relative abundance of 50.38%-51.95% and 16.36%-17.02%, respectively. Soil bacterial community at the phylum level was not significantly different between CK and QH. At the genus level, the relative abundance of MND1(3.54%), Spinstomonas(3.50%), Nitrospira(1.53%), and Rhizobacter(1.05%) was significantly higher and that of Gemmatimonas, Candidatus＿Solibacter, and Bryophytes was lower in QH treatment than in the CK. The plant height, leaf length, leaf width, and petiole length of N. incisum in QH treatment was significantly increased and the underground biomass rose by 71.43% compared with those in the CK. Thus, intercropping with V. faba promoted the aboveground growth of N. incisum and improved the yield of root and rhizome. Moreover, the content of notopterol and isoimperatorin increased by 37.96% and 4.09% in QH treatment, respectively, indicating that the intercropping with V. faba boosted the accumulation of secondary metabolites in N. incisum. Pearson's correlation analysis showed that the soil bacterial community was mainly influenced by the soil factors including the content of soil available nutrients, soil organic matter, pH value, and soil water. The influence was in the order: total potassium>total nitrogen>pH>organic matter>available potassium>soil water content>available nitrogen>available phosphorus. In conclusion, the intercropping with V. faba altered soil microenvironment and also increased the yield and accumulation of secondary metabolites of N. incisum, which is a promising ecological planting model for N. incisum.

[Quality evaluation of fried Glycyrrhizae Radix et Rhizoma pieces by HPLC fingerprint and multicomponent quantitative analysis].

To establish the HPLC fingerprint and multi-component determination method of fried Glycyrrhizae Radix et Rhizoma pieces. HPLC analysis was performed on Thermo Acclaim ~(TM)120 C_(18) column(4.6 mm×250 mm, 5 µm). Acetonitrile-0.1% phosphoric acid aqueous solution was taken as the mobile phase for gradient elution. The flow rate was 1 mL·min~(-1),the column temperature was maintained at 30 ℃, and the detection wavelength was 237 nm and 360 nm. The similarity of 15 batches of fried Glycyrrhizae Radix et Rhizoma pieces was higher than 0.849, and 17 common peaks were identified. Liquiritin, isoliquiritin apioside, isoliquiritin, liquiritigenin, isoliquiritigenin and glycyrrhizic acid were identified; among them, the mass fractions of Liquiritin, isoliquiritin apioside, isoliquiritin, liquiritigenin, glycyrrhizic acid were were 0.519%-3.058%, 0.227%-0.389%, 0.070%-0.439%, 0.038%-0.173%, 1.381%-4.252%, respectively. According to the cluster analysis, the 15 batches of decoction pieces were classified into three categories; principal component analysis screened out four principal components, with the cumulative variance contribution rate of 86.630%, indicating that the principal components contained most information of original data. Partial least squares discriminant ana-lysis marked 6 differential components in the decoction pieces. The established fingerprint and multicomponent determination are stable and reliable, and can provide a reference for the quality control of Radix Glycyrrhizae Radix et Rhizomae and fried Glycyrrhizae Radix et Rhizoma pieces.

Challenges and strategies in progress of drug delivery system for traditional Chinese medicine Salviae Miltiorrhizae Radix et Rhizoma (Danshen).

Traditional Chinese medicines (TCMs), with a history of thousands of years, are widely used clinically with effective treatment. However, the drug delivery systems (DDSs) for TCMs remains major challenges due to the characteristics of multi-components including alkaloids, flavones, anthraquinones, glycosides, proteins, volatile oils and other types. Therefore, the novel preparations and technology of modern pharmaceutics is introduced to improve TCM therapeutic effects due to instability and low bioavailability of active ingredients. Salviae Miltiorrhizae Radix et Rhizoma, the radix and rhizomes of Salvia miltiorrhiza Bunge (Danshen in Chinese), is a well known Chinese herbal medicine for protecting the cardiovascular system, with active ingredients mainly including lipophilic tanshinones and hydrophilic salvianolic acids. In this review, this drug is taken as an example to present challenges and strategies in progress of DDSs for TCMs. This review would also summary the characteristics of active ingredients in it including physicochemical properties and pharmacological effects. The purpose of this review is to provide inspirations and ideas for the DDSs designed from TCMs by summarizing the advances on DDSs for both single- and multi-component from Danshen.

[Comparison of soil hydraulic properties in wild and cultivated areas of Notopterygium incisum].

To clarify the difference of soil moisture characteristics between mixed broad leaf-conifer forest soil and artificial cultivation of Notopterygium incisum, the HYPROP system and the dew point potential meter were used to determine soil water retention curves(SWRC) for samples of two horizons(i.e. 2-7 cm, 10-15 cm). The basic physical and chemical properties of soil and its water characteristic parameters were also determined. The result showed as fllows:①The bulk density of mixed coniferous-broad leaf forest soil was between 0.33 and 0.52 g·cm~(-3), significantly lower than the corresponding value of field soil(1.01-1.18 g·cm~(-3))(P<0.05), While the organic matter content was significantly higher than the corresponding value of field soil(P<0.05). ②The saturated water content(θ_s), field water holding capacity(θ_(FC)) and Water that can be effectively utilized by plants(θ_(PAC)) of mixed coniferous-broadleaved forest soil were significantly higher than the corresponding value of field soil(P<0.05), while the retained water content(θ_r) value that cannot be effectively utilized by plants was significantly lower than that of field soil(P<0.05). ③The values of structural porosity(0.13-0.24 cm~3·cm~(-3)) and Matrix porosity(0.34-0.44 cm~3·cm~(-3)) of mixed coniferous-broadleaved forest soil were higher than the corresponding values of field soil. Therefore, with low bulk density and high content of organic matter, mixed coniferous-broadleaved forest soil can store more water in soil in the form of effective water to meet the needs of plants for water, thus possibly forming high quality medicinal materials of Notopterygii Rhizoma et Radix. In conclusion, the results of this study can provide theoretical basis guidance for soil structure improvement and water management to form high quality medicinal materials in the artificial cultivation of N. incisum.

[Framework construction and standardization practice of standard system for Sichuan Dao-di herbs].

Dao-di herbs is one of the characteristics of traditional Chinese medicine different from other ethnic medicine. Sichuan province is rich in varieties and resources of Dao-di herbs, and its development scale and benefits are not obvious in recent decades due to the lag of standards behind the development of the times and objective needs. From the point of view of the whole process and the whole industrial chain, the significance of standardization system for quality assurance, healthy development of the industry, and development of the industry of Sichuan Dao-di herbs are presented in this paper. At present, Sichuan has made every effort to promote the construction and practice of the standardization system for Sichuan Dao-di herbs, to promote the rapid and high-quality development of Dao-di herbs industry in Sichuan.

[Correlation between growth characteristics and quality of rhizomes of Notopterygium incisum under wild tending].

Study the growth and development process of rhizomes(bamboo-like part) of Notopterygium incisum and the changes of carbohydrate, endogenous hormones and secondary metabolites, and provide theoretical guidance for the formation of high-quality N. incisum medicinal commodities under artificial cultivation. The One-year-old seedlings were transplanted to the original habitat,and the growth and physiological characteristics of N. incisum were dynamically monitored. The results showed that: ① Seedlings transplanted to the original habitat in spring could form rhizomes(bamboo-like part) in the same year. ② After 60 days of transplantation, the root length and root diameter of underground part of N. incisum had increased rapidly, and carbohydrate content in roots and rhizomes had accumulated rapidly. After 120 days of transplantation, the roots and rhizomes of underground part had grown slowly, and starch content in roots and rhizomes increased continuously, while sucrose and total soluble sugar content decreased gradually. ③ The content of abscisic acid(ABA) in rhizomes decreased firstly and then increased, while the indole acetic acid(IAA) content stabilized firstly and then increased rapidly, and the contents of gibberellin(GA_3) and zeatin riboside(ZR) continued to increase. ④ The content of notopterol in rhizomes was higher than that in roots, while the content of isoimperatorin was lower than that in roots, but the total content of the both in rhizomes was higher than that in roots. Therefore, N. incisum can form rhizomes with high content of secondary metabolites under wild tending, and the growth and development of rhizomes are closely related to changes in carbohydrates and are regulated by related endogenous hormones.

[Ethnobotanical study of Juenang cultural area in Rangtang county of northwestern Sichuan].

Indigenous knowledge and traditional culture for sustainable use of native plants in Juenang cultural region of Rangtang county, Aba Zang and Qiang Prefecture of Sichuan province, have been characterized in this paper followed the principles and methods of ethnobotany. The results indicate that 38 species from 27 families(including 6 species of fungi) are ethnobotanically used commonly in this area. Of 38 species of the native plants, 13 species from 12 families are collected for eatables and vegetables, 12 families and 16 species of indigenous plants for medicinal and edible use, 4 species from 4 families for decoration, 4 species from 4 families used for building materials or firewood, and 1 species from 1 families used for religious folklore. Under the influence of Juenang culture and Tibetan culture, indigenous knowledge such as instinctive reverence and gratitude for nature, protection ecological environment and habitats, and moderate use of natural resources(especially wild bioresource), have been gotten passed on from generation to generation in Juenang culture region of Rangtang county, which is of great significance to the protection of local bioresources and environment, including ethnic medicinal plants, and also to provide practical guidance for biodiversity conservation and ecological restoration in those alpine ecological vulnerable areas.

[Effects of soil water content on growth and accumulation of active ingredients of Notopterygium incisum].

To investigate the adaptive mechanism of Notopterygium incisum to water changes, one-year-old seedlings were used as test materials. The characteristics of growth, physiology, and active ingredients of N. incisum were studied at different soil water content by pot experiments. The result showed that: ①The water content at 100% field capacity is conducive to the growth and accumulation of biomass of N. incisum. The leaf length, petiole length, petiole diameter, root diameter, root length and biomass of underground dry of N. incisum were all significantly increased at the 100% field capacity, and they slightly declined at 70% field capacity. 20% field capacity could not provide the necessary water to growth of N. incisum, all N. incisum withered and died. ②With the extension of moisture treatment time, the relative content of chlorophyll (SPAD) in leaves and the activity of peroxidase (POD) in rhizome showed a trend of increasing firstly, decreasing then; the tendency of activity of superoxide dismutase (SOD) in rhizome increased; the content of malondialdehyde (MDA) in rhizome decreased firstly and increased then;. For the late test, the SPAD value, the activity of POD and SOD in N. incisum at the 40% field capacity were lower than 70% field capacity and 100 field capacity, while the content of MDA in rhizome were higher than 70% field capacity and 100% field capacity. ③ At 70% field capacity, the active ingredients accumulated most in the N. incisum. At the 70% field capacity, the notopterol and isoimperatorinwerehigher than100 field capacity and 40 field capacity. In summary, the soil water content at 70%-100% field capacity would contribute to the growth and accumulation of active ingredients of N. incisum.

[Industrialization condition and development strategy of Notopterygii Rhizoma et Radix].

Notopterygii Rhizoma et Radix, the underground part of Notopterygium incisum and N. franchetii, is used as a classical traditional Chinese medicine, and as raw materials for 262 Chinese patent drugs production in 694 pharmaceutical factories currently. It plays an important role in the whole Chinese medicine industry with irreplaceable important economic and social values. However, wild resource of was abruptly depleted, and large-scale artificial cultivation has been inapplicable. In this study, Utilization history and the industrialization status of Notopterygii Rhizoma et Radix were summarized. Resource distribution, ecological suitability of Notopterygii Rhizoma et Radix and core technologies for seeds production, seedling breeding, large-scale cultivation has been reported by current studies, and basic conditions are already available for industrialization production of Notopterygii Rhizoma et Radix. However, there still some key technical problems need to be solved in the further research, and some policy dimensions need to be focused on in the coming industrialization cultivation of Notopterygii Rhizoma et Radix.

[Cultural regionalization for Notopterygium incisum based on 3S technology platform â ¢. Functional regionalization for cultivation based on suitability evaluation of growth and production quality].

Based on the research results of suitability evaluation of growth and production quality, a functional production cultivation regionalization with high feasibility and operability to solve the problem of the separation of high quality and high yield were formatted for protection, wild monitoring, and cultivation of this plant by weighted sum of spatial suitability data of ecology and quality, as well as integrated with land use and cover data. The results of the study revealed that good quality and high yield area were mainly distributed in the original production areas in Sichuan province and where could carry out monitoring and commercialization cultivation. This method is expected to overcome shortage of traditional regionalization methods difficult to distinguish the contribution of ecological factors and quality factors, which provide an innovative theory and methodology for regionalization, and is helpful to practical application of wild resource protection, nature research, monitoring, and commercialization cultivation for Chinese material medica.

[Dynamics of plant biomass and nutrients accumulation of Notopterygium incisum in artificial cultivation].

In this study,field cultivation experiments of Notopterygium incisum had been carried out for three years, and samples had been collected monthly during growth seasons, and biomass and nutrient elements of aerial and underground part of sampled plants had been determined to assess their seasonal and interannual dynamics respectively. The results showed that biomass of underground part (dry weight) increased mainly in the second year after seedling transplanting, i.e., biomass increased about 32 times in the second year whilst less than 6 times and 2 times in the first year and in the third year, respectively. Therefore, efforts for yield improvement should be focused on the first two year in artificial cultivation of N. incisum. Accumulation of nutrient elements increased steady in the underground part during the first and second year, then showed a sharp decline in the first phase of growth season in the third year, while its accumulation in July to August of third year was higher than the value of second year. Ca, Fe, B and Zn were larger demand nutrient elements to meet growth demands whether for the underground part or aerial part during the second year and third year for N. incisum cultivation. This result provided instructional guidance and scientific basis for artificial cultivation and specific fertilizer of N. incisum.

[Effect of lupeol on migration and invasion of human breast cancer MDA-MB-231 cells and its mechanism].

In this study, we examined the inhibitory effects of lupeol, an extract of Euphorbia fischerana Steud, on human breast cancer MDA-MB-231 cells migration and invasion. Lupeol was found to inhibit the invasion of MDA-MB-231 in the cell adhesion assay, transwell test and wound healing assay. The expression of cyclooxygenase-2 (COX-2), matrix metalloproteinase-2 (MMP-2), -9 (MMP-9) and nuclear transcription factor-kappa B (NF-κB) p65 in breast cancer following treatment with different concentrations of lupeol was analyzed with Western blot. Lupeol inhibited the migration and invasion of MDA-MB-231 cells in a dose- dependent manner in vitro (P < 0.05). The expression of COX-2, MMP-2, MMP-9 and NF-κB p65 levels was significantly down-regulated. These observations suggest that lupeol can inhibit the abilities of invasion of MDA-MB-231 cells by inhibiting the protein expression of COX-2, MMP-2 and MMP-9. Its mechanism may be related to inhibition of the nuclear NF-κB signal pathway.

[Comparison of chemical composition between fresh and processed Bufonis Venenum by UPLC-TQ-MS].

Toad venom is the Bufo bufo gargarizans or B. melanostictus after the ears of the gland secretion, used in the treatment of various cancers in recent years. Research shows that the main anti-tumor components in bufadienolide. Bufadienolide have free type structure and conjunct type structure. To identify and clarify the difference between bufogenin and bufotoxin contained in Bufonis Venenum, which was from B. bufo gargarizans, an UPLC-TQ-MS method has been established. UPLC-TQ-MS method was used to identify and quantify the major bufadienolides in Bufonis Venenum. UPLC-TQ-MS assay with positive ion mode was performed on a Waters ACQUITY UPLC BEH C, (2.1 mm x 100 mm, 1.7 µm) with the mobile phase consisting of 0. 1% aqueous formic and acidacetonitrile in gradient elution at a flow rate of 0.4 mL · min⁻¹ and the column temperature was set at 35 °C. By comparing their retention time and high resolution mass data of Bufonis Venenum extracts, 37 effective components were primarily identified by MS/MS analysis in positive ion mode. Twenty-six of them were free-type bufadienolides (bufogenin), 11 of them were conjugated bufadienolides. There were significant differences in the main composition between fresh and processed Bufonis Venenum. The study found that the chemical composition of toad venom through great changes after processing, conjunct type content is much less, free type content as well change.

Acute Suppurative Parotitis Treatment by Diode Laser Combined with ER:YAG Laser.

BACKGROUND AND AIM: The diode laser combined with Er:YAG laser is a new treatment modality for acute sialadenitis. A 78-year-old woman with acute suppurative parotitis was treated by traditional probe to the duct orifice with oral antibiotics for 2 weeks. The symptoms and signs did not subside after treatment. The Er:YAG laser was used to reduce severe infection and inflammation and low level laser therapy (LLLT) was applied to relieve pain sensation during incision and drainage. Less scar formation and obstruction was observed after the laser treatments. RESULTS: Purulent secretions from the Stensen duct was noted after milking the parotid gland. The symptoms and signs were significantly relieved after combined laser treatments. The patient experienced no pain during the course of treatment. No recurrence of the symptoms and signs was noted after 1-year follow-up, and the prognosis was very good. CONCLUSION: The hemostatic properties of the diode laser enable better control of the surgical field and faster healing of the wound lesions. The bactericidal effect of Er:YAG lasers has been proved by many researchers, and has been shown to reduce infection and inflammation for better wound healing. The combined laser therapy of diode and Er:YAG lasers is recommended in treating acute sialadenitis.

[Analyze on the component of rosmarinic acid in Prunella vulgaris and its effect on alpha-glycosidase activity].

OBJECTIVE: To analyze rosmarinic acid in Prunella vulgaris and its effect on the activity of alpha-glycosidase. METHODS: Qualitative and quantitative analyses of Rosmarinic acid in Prunella vulgaris were carried out by HPLC. The activity of different micro reaction systems like alpha-amylase, alpha-glucosidase and alpha-maltase, which were added to Rosmarinic acid and Acarbose, was determined by Bernfeld, pNPG and GOD. RESULTS: The contents of Rosmarinic acid in the aqueous extract and its dry powder, and extractum of Prunella vulgaris were 0.1494, 0.1657 and 0.2739 mg/g respectively, equal to crude drug. The Rosmarinic acid inhibited alpha-glycosidase, and its inhibition from alpha-maltase in small intestine was noncompetitive. CONCLUSION: The aqueous extract of Prunella vulgaris and its extractum's inhibition from alpha-glycosidase is related to Rosmarinic acid.

[Effect of total body irradiation on cellular senescence related indexes of bone marrow mesenchymal stem cells].

The aim of this study was to explore the changes in cellular senescence related indexes of bone marrow mesenchymal stem cells (BMMSCs) after total body irradiation (TBI). At different time points after 4 Gy irradiation, BMMSCs were isolated from male C57BL/6 mice and cultured. Morphology, senescence-associated beta-galactosidase (SA-beta-gal) staining and cell cycle analysis were used to evaluate the changes in BMMSCs at cellular level while real-time RT-PCR was used to detect the alterations in senescence related gene expression including p16INK4a, p21Cip1/Waf1, p53 and TGF-beta1. The results showed that within 4 weeks after exposure to 4 Gy TBI, the morphology of BMMSCs and the expression level of SA-beta-gal were not significantly changed, the cellular senescence-related cell cycle arrest was not occurred and the senescence related gene expression level was not increased. It is concluded that at the early stage after 4 Gy TBI, the related molecular level of cellular senescence in BMMSCs is not changed.

[Reduction of bone marrow mesenchymal stem/progenitor cells pool and alteration of their osteogenesis potential caused by total body irradiation].

To investigate the effect of irradiation on the quantity and osteogenesis potential of BMMSCs and to explore the response of them in the irradiation stress and its contribution to long-term effects of radiation-induced bone and hematologic injury, a total body irradiation (TBI) murine model was adopted. The number of CFU-F and cell cycle profile of BMMSCs were analyzed at different time points before and after TBI. Osteogenic differentiation was evaluated by Von Kossa staining, expressions of osteogenesis-related genes and transcriptional coactivator with PDZ-binding motif (TAZ) were detected by real-time RT-PCR. The results showed that the number of CFU-F decreased greatly at day 28 after TBI. At day 3 after TBI, more cells entered cell cycle and the osteogenesis potential was greatly enhanced followed by recovery of cell cycle distribution and significant defect in osteoblast differentiation respectively, meanwhile the expression of TAZ was changed. It is concluded that TBI results in the reduction of bone marrow mesenchymal stem/progenitor cell pool and alters the osteogenesis potential of BMMSCs, which is related to the change of TAZ expression.

Dispersion of ventricular mRNA of RyR2 and SERCA2 associated with arrhythmogenesis in rats.

AIM: To investigate the effect of CPU86017 on the changes of mRNA abundance of different calcium handling system in infarcted heart. METHODS: Rats were subjected to left coronary ligation to induce myocardial infarction (MI). The treatment with either propranolol (Pro) 5 mg/kg ip or CPU86017 1, 2, and 4 mg/kg ip was initiated on the next day of operation and continued for 20 d. Medication with isoproterenol (Isop) 3 mg/kg sc started on the d 17-21. Ventricular mRNA abundance of ryanodine receptor 2 (RyR2), sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2), L-type Ca(2+) channel, and Na(+)/Ca(2+)exchanger (NCX1) were measured. RESULTS: Arrhythmic scores (AS) in the Isop group was raised up to 5.27+/-1.75 (P<0.01) vs myocardial infarction group 2.25+/-2.04 and sham group 1.50+/-1.73. The AS was depressed by Pro (1.63+/-1.53, P<0.01 vs Isop), and CPU86017 2 and 4 mg/kg (3.00+/-1.24, and 1.70+/-1.85, P<0.01 vs Isop). The significant dispersion of depressed mRNA abundance of RyR2 and SERCA2 was associated with an increase in AS in Isop group, and it was much depressed in the left than the right ventricle. The dispersion and depression of mRNA were restored significantly by Pro and CPU86017, associated with suppression on AS. In Isop group, the mRNA abundance of L-type Ca(2+) channel was not changed; and a moderate increase in the mRNA of NCX1 was seen, the changes were regressed by Pro and CPU86017. CONCLUSION: Isop-induced arrhythmogenesis in MI heart was correlated mainly with a dispersion of depressed mRNA abundance in ventricle likely due to the consequence of PKA over-phosphorylation. A suppression of arrhythmia by Pro and CPU86017 resulted from a regression of the dispersion and depression of RyR2 and SERCA2.

Matrix is the site of indirect effects of propranolol on the ion channelopathies in cardiac remodeling by L-thyroxine.

Cardiac remodeling by chronic L-thyroxine medication causes exaggerated cardiac arrhythmias in relation to ion channelopathies that involve multichannels. The matrix of lipid membrane is likely the key site where channel lesions, possibly will develop and be benefitted by drug intervention. Cardiac remodeling in rats and guinea pigs was developed by L-thyroxine 0.5 mg/kg SC for 10 days. Propranolol was instituted on days 8-10. Whole cell holding was applied to measure ion currents. An increase in HR, dispersion of QTc, mitochondrial Na+/K+ ATPase, Ca2+/Mg2+ ATPase, and LPO production were found in the model. T3 and T4 levels in plasma were high. Propranolol was effective in regressing cardiac remodeling, together with lowering all the parameters and the enhanced I(Ca.L),I(KS), and I(KR) currents, but T3 and T4 remained basically unchanged. The changes in ion channels are likely the consequence of the cardiac remodeling that is formed by oxidative stress and increased energy consumption provoked by L-thyroxine. The benefit of propranolol on the disordered ion channels is mediated by its ability to ameliorate lesions of the matrix.