目的 探討梓醇對塵肺模型大鼠運(yùn)動能力及骨骼肌功能的改善作用。方法 通過氣管注射石英粉塵建立大鼠慢性塵肺模型，造模3個(gè)月后，取造模大鼠30只隨機(jī)分為3組：模型組、梓醇100mg·kg^-1組、梓醇50mg·kg^-1組，每組10只，另取10只正常大鼠作為對照組。大鼠ig給藥，每天1次，每周給藥6d，連續(xù)給藥8周。觀察大鼠一般狀況及體質(zhì)量變化；采用小動物跑臺檢測大鼠的1次力竭運(yùn)動時(shí)間；采用抓力測定儀進(jìn)行大鼠骨骼肌力量檢測；解剖大鼠取同一位置肺葉，HE染色用于觀察肺組織基本結(jié)構(gòu)及炎癥反應(yīng)等狀態(tài)，Masson染色用于觀察肺組織膠原沉積和纖維化情況；取雙側(cè)后肢的腓腸肌和比目魚肌，稱質(zhì)量，計(jì)算質(zhì)量指數(shù)（肌肉質(zhì)量/體質(zhì)量）；試劑盒法檢測腓腸肌組織線粒體膜電位（△φ_m）和腺嘌呤核苷三磷酸（ATP）水平；試劑盒法檢測腓腸肌組織超氧化物歧化酶（SOD）活性、丙二醛（MDA）水平及琥珀酸脫氫酶（SDH）活性；實(shí)時(shí)熒光定量PCR（qRT-PCR）法檢測過線粒體生物發(fā)生相關(guān)基因——氧化物酶體增殖物激活受體γ輔激活因子1α（Pgc-1α）、核呼吸因子1（Nrf1）、線粒體轉(zhuǎn)錄因子A（Tfam）的mRNA表達(dá)水平。結(jié)果 與模型組比較，梓醇100、50mg·kg^-1對塵肺大鼠肺部炎癥和纖維未見顯著改善；梓醇100、50mg·kg^-1均能顯著延長塵肺大鼠跑動力竭時(shí)間（P＜0.05、0.01）；梓醇可顯著增加塵肺大鼠的肌肉抓力，其中100mg·kg^-1組差異顯著（P＜0.05）；梓醇100mg·kg^-1組塵肺大鼠的腓腸肌和比目魚肌質(zhì)量指數(shù)顯著增加（P＜0.05、0.01），50mg·kg^-1組的比目魚肌質(zhì)量指數(shù)顯著增加（P＜0.05）；梓醇可明顯升高塵肺大鼠腓腸肌ATP水平和△φ_m，其中100mg·kg^-1組差異顯著（P＜0.05）；梓醇100mg·kg^-1顯著增加腓腸肌SDH和SOD活力、同時(shí)降低MDA水平（P＜0.05、0.01），梓醇50mg·kg^-1顯著增加腓腸肌SDH活力、同時(shí)降低MDA水平（P＜0.05、0.01）；梓醇100、50mg·kg^-1顯著上調(diào)腓腸肌中線粒體生物發(fā)生相關(guān)基因表達(dá)（P＜0.05、0.01）。結(jié)論 梓醇可以調(diào)節(jié)塵肺模型大鼠骨骼肌線粒體功能，減輕肌肉萎縮并增強(qiáng)運(yùn)動能力，此作用可能通過PGC-1α/NRF1、TFAM途徑促進(jìn)線粒體生物發(fā)生而介導(dǎo)。

Objective To investigate the effect of catalpol on the exercise ability and skeletal muscle function in pneumoconiosis rats.Methods The rat model of chronic pneumoconiosis was established by intratracheal injection of quartz dust. Three months after the model was established, thirty model rats were randomly divided into three groups: model group, catalpol 100 mg·kg^-1 group and catalpol 50 mg·kg^-1 group with 10 rats in each group, and 10 normal rats were selected as control group. The rats were ig given the drug, once a day, for six days a week for eight weeks. The general condition and body mass of rats were observed. The time of one exhaustive exercise of rats was measured by small animal running table. The muscle strength of rats was measured by grip force analyzer. HE staining was used to observe the basic structure and inflammatory response of lung tissue, and Masson staining was used to observe the collagen deposition and fibrosis of lung tissue. The gastrocnemius and soleus muscles of the bilateral hind limbs were taken and weighed, and the mass index (muscle mass/body mass) was calculated. Mitochondrial membrane potential (△φ_m) and adenine riboside triphosphate (ATP) levels in gastrocnemius were determined by kit method. The activity of superoxide dismutase (SOD), malondialdehyde (MDA) and succinate dehydrogenase (SDH) in gastrocnemius were detected by kit method. Real-time quantitative fluorescence PCR (qRT-PCR) was used to detect the mRNA expression levels of oxisome proliferator-activated receptor γ -coactivator 1α (Pgc-1α), nuclear respiratory factor 1 (Nrf1) and mitochondrial transcription factor A (Tfam).Results Compared with model group, catalpol 100 and 50 mg·kg^-1 did not significantly improve pulmonary inflammation and fiber in rats with pneumoconiosis. Compared with model group, catalpol of 100 and 50 mg·kg^-1 could significantly prolong the running exhaustion time of rats with pneumoconiosis (P <0.05, 0.01). Catalpol significantly increased the muscle gripping power of rats with pneumoconiosis, and the difference was significant in 100 mg·kg^-1 group compared with model group (P <0.05). The gastrocnemius muscle mass index and soleus muscle mass index of pneumoconiosis rats in catalpol 100 mg·kg^-1 group were significantly increased (P <0.05, 0.01), and soleus muscle mass index in 50 mg ·kg^-1 group was significantly increased compared with model group (P <0.05). Catalpol significantly increased ATP level and △φm in gastrocnemius of pneumoconiosis rats, and the difference was significant in 100 mg·kg^-1 group (P <0.05). Catalpol of 100 mg·kg^-1 significantly increased the activities of SDH and SOD in gastrocnemius and decreased the level of MDA (P <0.05, 0.01), and catalpol of 50 mg·kg^-1 significantly increased the activities of SDH and decreased the level of MDA in gastrocnemius (P <0.05, 0.01). Catalpol of 100 and 50 mg·kg^-1 significantly up-regulated the expression of mitochondrial biogenesis related genes in gastrocnemius (P <0.05, 0.01).Conclusion Catalpol can regulate the mitochondrial function of skeletal muscle in pneumoconiosis model rats, alleviate muscle atrophy and enhance exercise ability, which may be through PGC-1 α-Nrf1/TFAM pathways promoting mitochondrial biogenesis.

R965

南京市衛(wèi)生科技發(fā)展項(xiàng)目資助(YKK21188);青海省高端創(chuàng)新人才千人計(jì)劃項(xiàng)目(2018年)