OBJECTIVE: To investigate whether the G protein-coupled estrogen receptor (GPER) can attenuates acute lung injury in mice with exertional heat stroke (EHS) by inhibiting ferroptosis. METHODS: Sixty SPF-grade male C57BL/6 mice were randomly divided into four groups: normal control group (control group), EHS model group (EHS group), dimethyl sulfoxide (DMSO) solvent group (EHS+DMSO group), and GPER-specific agonist G1 group (EHS+G1 group), with 15 mice in each group. All mice underwent 14 days of adaptive training at 24-26 centigrade before modeling, and the EHS model was established using a high-temperature treadmill device. After successful modeling, the mice were allowed to cool naturally at room temperature. In the EHS+G1 group, 40 μg/kg of the GPER-specific agonist G1 was slowly injected intraperitoneally immediately after modeling. In the EHS+DMSO group, 40 μg/kg of DMSO was slowly injected intraperitoneally immediately after modeling. The control group received no treatment. Five hours after modeling, abdominal aortic blood was collected, and lung tissues were harvested after euthanasia. The lung coefficient was calculated to evaluate lung injury. Lung histopathological changes were observed under a light microscope after hematoxylin-eosin (HE) staining, and a lung histopathological score was assigned. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), malondialdehyde (MDA), and Fe²⁺ in lung tissue. Immunofluorescence was used to detect the expression of glutathione peroxidase 4 (GPX4). Real-time polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of GPX4, ferroportin 1 (FPN1), and ferritin heavy chain 1 (FTH1). Western blotting was performed to detect the protein expression of GPX4, FPN1, and FTH1. RESULTS: Compared with the control group, the lung coefficient and lung histopathological score were significantly increased in the EHS group. HE staining showed significant thickening and unevenness of the alveolar septa and alveolar walls, partial alveolar collapse, and extensive erythrocyte, inflammatory cell, and plasma-like material extravasation in the alveolar spaces. Serum levels of TNF-α, IL-1β, MDA, and Fe²⁺ were significantly elevated. Immunofluorescence staining showed a significant decrease in GPX4-positive expression in lung tissue. Western blotting and RT-PCR showed significantly reduced protein and mRNA expression of GPX4, FPN1, and FTH1 in lung tissue. Compared with the EHS group, the EHS+G1 group showed a significant reduction in lung coefficient and lung histopathological score [lung coefficient (mg/g): 3.9±0.1 vs. 4.6±0.3, lung histopathological score: 4.2±0.2 vs. 6.9±0.2, both P < 0.05]. HE staining revealed reduced severity of lung tissue fluid extravasation, inflammatory infiltration, decreased hemorrhage, and less severe alveolar structural damage. Serum levels of TNF-α, IL-1β, MDA, and Fe²⁺ were significantly reduced [TNF-α (ng/L): 44.3±0.2 vs. 64.6±0.3, IL-1β (ng/L): 69.3±0.4 vs. 97.8±0.2, MDA (nmol/L): 2.8±0.3 vs. 3.6±0.5, Fe²⁺ (nmol/L): 0.021±0.004 vs. 0.028±0.004, all P < 0.05]. Immunofluorescence staining showed a significant decrease in GPX4-positive expression in lung tissue (fluorescence intensity: 35.53±2.41 vs. 16.45±0.31, P < 0.05). RT-PCR and Western blotting showed significantly increased mRNA and protein expression of GPX4, FPN1, and FTH1 in lung tissue [mRNA expression: GPX4 mRNA (2^-ΔΔCt): 0.44±0.05 vs. 0.09±0.01, FPN1 mRNA (2^-ΔΔCt): 0.77±0.17 vs. 0.42±0.14, FTH1 mRNA (2^-ΔΔCt): 0.75±0.04 vs. 0.58±0.01; protein expression: GPX4/β-actin: 0.96±0.11 vs. 0.24±0.04, FPN1/β-actin: 1.26±0.21 vs. 0.44±0.14, FTH1/β-actin: 0.27±0.12 vs. 0.15±0.07; all P < 0.05]. However, there were no statistically significant differences in any of the above indicators between the EHS+DMSO group and the EHS group. CONCLUSION Activation of GPER can attenuate EHS-related lung injury in mice, and its mechanism may be related to the activation of the GPX4 signaling pathway and inhibition of ferroptosis.
Animals ; Mice, Inbred C57BL ; Male ; Mice ; Heat Stroke/metabolism* ; Receptors, G-Protein-Coupled ; Ferroptosis ; Receptors, Estrogen ; Acute Lung Injury/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-1beta/metabolism* ; Lung Injury ; Lung/metabolism*

This paper clarified the scientific connotation of the changes in cold and heat properties of Arisaematis Rhizoma and Arisaema Cum Bile through investigating the changes of substance and energy metabolism after drug intervention in the rats with normal and cold/heat syndrome, so as to improve the method of evaluating the drug properties of Chinese medicine. After one week of adaptive feeding, healthy male SD rats were randomly divided into three parts: normal rats, heat syndrome rat models, and cold syndrome rat models. Through ice water bath and oral euthyrox(120 μg·kg~(-1)), the models of cold syndrome and heat syndrome were induced, respectively. The models were made at 9:00 am. and administrated by gavage at 3:00 pm. every day. All administration groups were administrated with Arisaematis Rhizoma and Arisaema Cum Bile decoction, respectively, and the blank group was given the same dose of normal saline. After continuous administration for 15 d, the rats were anesthetized by chloral hydrate, blood was taken from abdominal aorta, and the hearts and livers were removed and stored at-80 ℃. The changes in the body weight and anal temperature of rats during administration were detected, and the liver coefficient of rats was detected after removing the liver. Enzyme-linked immunosorbent assay(ELISA) was adopted to detect the expression level of the indexes related to substance and energy metabolism in liver and heart of rat, and Western blot was used to detect the expression of key proteins in AMPK/mTOR signaling pathway for further verification. The results showed that Arisaematis Rhizoma enhanced the expression level of enzymes related to substance and energy metabolism in the normal and cold and heat syndrome rat models, and increased anal temperature, which exhibited warm(hot) drug property. Arisaema Cum Bile inhibited the level of substance and energy metabolism in rats, and reduced anal temperature, which showed cold(cool) drug property. Chinese Pharmacopoeia has recorded "Arisaematis Rhizoma has warm property and Arisaema Cum Bile has cool property", which is consistent with the phenomenon in this study. Therefore, it is feasible to evaluate the drug properties of Chinese medicine based on the substance and energy metabolism of normal and cold/heat syndrome model rats, which completes the method of evaluating drug properties of Chinese medicine.
AMP-Activated Protein Kinases ; Animals ; Arisaema/chemistry* ; Bile ; Chloral Hydrate ; Cold-Shock Response/drug effects* ; Drugs, Chinese Herbal/therapeutic use* ; Energy Metabolism ; Heat Stroke/therapy* ; Hot Temperature ; Male ; Rats ; Rats, Sprague-Dawley ; Saline Solution ; Syndrome ; TOR Serine-Threonine Kinases ; Thyroxine ; Water

OBJECTIVEGua Sha and Blood-letting at the acupoints were Chinese traditional therapies for heatstroke. The purpose of present study was to assess the therapeutic effect of Gua Sha on the DU Meridian and Bladder Meridian combined with Blood-letting acupoints at Shixuan (EX-UE 11) and Weizhong (BL 40) on heatstroke.

METHODSAnesthetized rats, immediately after the onset of heatstroke, were divided into four major groups: Gua Sha group, Blood-letting group, Gua Sha combined with Blood-letting group and model group. They were exposed to ambient temperature of 43 °C to induce heatstroke. Another group of rats were exposed to room temperature (26 °C) and used as normal control group. Their survival times were measured. In addition, their physiological and biochemical parameters were continuously monitored.

RESULTSWhen rats underwent heatstroke, their survival time values were found to be 21-25 min. Treatment of Gua Sha combined with Bloodletting greatly improved the survival time (230±22 min) during heatstroke. All heatstoke animals displayed and activated coagulation evidenced by increased prothrombin time (PT), activated partial thromboplastin time (aPTT), D-dimer, and decreased platelet count, protein C. Furthermore, the animals displayed systemic inflammation evidenced by increased the serum levels of cytokines interleukin-1ß (IL-1ß), tumor necrosis factor α (TNF-α) and malondialdehyde (MDA). Biochemical markers evidenced by cellular ischemia and injury/dysfunction included increased plasma levels of blood urea nitrogen (BUN), creatinine, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), and alkaline phosphatase (ALP) were all elevated during heatstroke. Core temperatures (Tco) were also increased during heatstroke. In contrast, the values of mean arterial pressure were signifificantly lower during heatstroke. These heatstroke reactions were all signifificantly suppressed by treatment of Gua Sha and Blood-letting, especially the combination therapy.

CONCLUSIONGua Sha combined with Blood-letting after heatstroke may improve survival by ameliorating systemic inflflammation, hypercoagulable state, and tissue ischemia and injury in multiple organs.

Animals ; Blood Coagulation Disorders ; drug therapy ; therapy ; Bloodletting ; Combined Modality Therapy ; Complementary Therapies ; methods ; Cytokines ; blood ; Heat Stroke ; physiopathology ; Inflammation ; drug therapy ; therapy ; Ischemia ; drug therapy ; therapy ; Male ; Malondialdehyde ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Survival Rate

The present study is to assess the prophylactic effect of quinacrine (QA) , an anti-malarial drug, against heatstroke in rats. Conscious rats were orally given equal volume normal saline or QA (dissolved in normal saline and final dosage for rats was 4.5, 9.0 and 18 mg x kg(-1)). An hour later rats were put into a warm water circulated hot chamber (41.0 +/- 0.5) degrees C. Rectal temperature (core temperature, T(co)) of rats in hot chamber was continuously monitored by a thermocouple. T(co) and survival time of rats showed that QA pre-treatment postponed the hyperthermia, and increased the survival time of rats in hot chamber. Primary striatum neurons' culture from new born rats was maintained with D-MEM and 10% FBS. After immuno-cytochemistry identification with antibodies against neural specific proteins, culture received 20 micromol x L(-1) QA only for 1 h and followed by 43.0 degrees C heat treatment for another hour, or 20 micromol x L(-1) QA for 1 h followed by 43.0 degrees C heat treatment for another hour. Control culture received heat treatment only. Cultures were labeled with the fluorescent indicator DPH and the relative membrane fluidity of neurons was measured with the help of fluorescent polarized spectrophotometer. [3H] Arachidonic acid (AA) labeled membrane of E. Coli cells was used as substrate to determine cPLA2 activity of neurons. Gas chromatography and mass spectrum were also employed to detect on the level of fatty acids level in rat striatum neurons. Results from cells indicated that inhibition of cPLA2, reduction the release of active fatty acids such as AA, and possibly, stabilization of the cell membrane which was disturbed by hot treatment, may contribute to the mechanism underlying heat protection and heatstroke preventive effects of quinacrine.
Animals ; Cells, Cultured ; Corpus Striatum ; drug effects ; pathology ; Fatty Acids ; metabolism ; Heat Stroke ; metabolism ; physiopathology ; prevention & control ; Hot Temperature ; adverse effects ; Male ; Membrane Fluidity ; drug effects ; Neurons ; enzymology ; metabolism ; physiology ; Phospholipases A2 ; metabolism ; Quinacrine ; pharmacology ; Rats ; Rats, Wistar

OBJECTIVETo study the effects of artesunate on CD14 and toll-like receptor 4 (TLR 4) expressions in peritoneal macrophages of mice with heat stroke endotoxemia.

METHODSKunming mice were randomly divided into the normal temperature group, the hyperthermia group, the normal saline (NS) group and the artesunate group (both i.p.60 mg/kg daily for consecutive five days). The normal temperature group was exposed to the condition of dry bulb temperature (Tdb) 25 degrees C +/- 0.5 degrees C and relative humidity (RH) 43% +/- 5% for 2 hours, while other groups were exposed to the condition of Tdb 35 degrees C +/- 0.5 degrees C and RH 65% +/- 5%. The mRNA expressions of CD14 and TLR 4 in peritoneal macrophages and concentrations of tumor necrosis factor alpha (TNF alpha) in plasma were observed in different time points (1 hour and 2 hour).

RESULTSThe mRNA expressions of CD14 and TLR 4 in the normal temperature group were 0.34% +/- 0.047% and 0.31% +/- 0.062% respectively. The expressions of two receptors at 1 hour in the hyperthermia group were significantly increased to 0.53% +/- 0.085% and 0.45% +/- 0.049% compared with the normal group and kept increased at 2 hour (P < 0.01). The mRNA expressions at 1 hour in the NS group were significantly increased but a little bit decreased at 2 hour. The mRNA expressions of CD14 and TLR 4 at 1 hour in the artesunate group were 0.26% +/- 0.051% and 0.25% +/- 0.084% respectively and a little bit decreased at 2 hour. The change of TNF-alpha in each group was almost consistent with the changes of CD14 and TLR 4.

CONCLUSIONArtesunate can reduce significantly the expressions of CD14 and TLR 4 in LPS signal transduction pathway and the concentration of TNF-alpha, which perhaps is one of the most important mechanisms that artesunate fights against endotoxemia.

Animals ; Artemisinins ; pharmacology ; Cells, Cultured ; Endotoxemia ; metabolism ; Female ; Gene Expression ; drug effects ; Heat Stroke ; metabolism ; Lipopolysaccharide Receptors ; biosynthesis ; genetics ; Macrophages, Peritoneal ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred Strains ; RNA, Messenger ; genetics ; Random Allocation ; Sesquiterpenes ; pharmacology ; Signal Transduction ; drug effects ; Toll-Like Receptor 4 ; biosynthesis ; genetics