Effect of acupuncture on the genetic expression of myocardial endothelin-1 and atrial natriuretic peptide in rats with stress-induced prehypertension

Objective:To explore the protective effect of acupuncture against myocardial injury in rats with stress-induced prehypertension (SIPH) by observing the genetic expression of myocardial endothelin-1 (ET-1) and atrial natriuretic peptide (ANP).Methods:Thirty-six Wistar rats were randomized into three groups:the control group,model group,and model + acupuncture (AP) group (n =12 rats per group).During the 11-day modeling period,the model group and the model + AP group experienced plantar electric stimulation in combination with noise exposure,and daily acupuncture intervention was applied simultaneously in the model + AP group;the control group did not experience modeling or acupuncture.Systolic pressure (SP) was measured the day before modeling began,and on the 3rd,5th,7th,9th,and 11th day after modeling initiation.On the 12th day,histopathological observation of the left ventricle was made with hematoxylin-eosin staining and quantitative genetic expression of myocardial ET-1,and ANP was tested by quantitative real-time polymerase chain reaction (PCR).Results:SP was higher in the model group than the control group on the 3rd,5th,7th,9th,and 11th days (all P <.01).SP in the model + AP group was lower than that in the control group on the 5th and 7th days (respectively,P =.008,P =.002) and on the 9th and 11th days (P =.029,P =.039).Hematoxylin-eosin staining showed normal myocardial cellular structure in the control group.The model group showed disordered arrangement of cardiac cells with morphological changes in some nuclei,including enlargement or dissolution;there was also infiltration of inflammatory cells and proliferation of collagen fibers.In the model + AP group,most of the myocardial cells were normally structured,and only part of the cells had morphological changes with enlarged nuclei or dissolution.Real-time PCR showed that expression of ET-1 and ANP mRNA in the model group was greater than the control group (respectively,P =.024,P =.000101).The model + AP group had lower expression of ET-1 and ANP mRNA compared with the model group (respectively,P =.033,P =.043).Conclusion:Acupuncture may lower blood pressure and downregulate the genetic expression of myocardial ET-1 and ANP in SIPH rats,suggesting a protective effect of acupuncture against myocardial damage.

Identification of sweet spots in shale-type and siltstone-type“shale oil systems”:A case study of the Chang 7 Member in Ordos Basin

Mid-high maturity shale oil is the most realistic field for the scale breakthrough of terrestrial shale oil production in China.Generally,three deficiencies hinder shale oil development in China:heavy oil density,small sweet spot areas,and poor distribution continuity.Thus,identifying the“sweet spots”in shale oil reservoirs is critical for the efficient exploration and development of terrestrial shale oil.This study targets the siltstone type(Class-Ⅱshale oil)and pure shale type(Class-Ⅲshale oil)of the Chang 7 Member in the Ordos Basin,and identifies three stratigraphic units,namely the hydrocarbon accumulation unit,hydrocarbon generation unit,and hydrocarbon retention unit,which together constitute the in-source“shale oil system”.The hydrocarbon accumulation unit is mainly siltstone,where the hydrocarbons are migrated from shales.It has favorable porethroat network connectivity with a pore connectivity ratio of 32–57%,being the siltstone-type sweet spots.The hydrocarbon generation unit is mainly composed of high-TOC mudstone/shale and is the main contributor to in-source hydrocarbon generation and expulsion.This unit has high three-dimensional connectivity(28–30%),as shown by the pore-throat network model,associated with vertical paths for hydrocarbon expulsion.The hydrocarbon retention unit is mainly composed of low-TOC mudstone/shale retaining self-generated and migrated hydrocarbons.The pore connectivity rate is 17–42%,and the pore-throat network connectivity direction is uneven.Light and low-carbon-number hydrocarbons are preferentially trapped or even sealed in small pores of the retention unit,forming the typical mudstone/shale-type sweet spots.In the process called shale oil intrasource migration,the oil migrates in source rocks causing component fractionation,which allows more shale oil to enrich in the hydrocarbon accumulation and retention units to form sweet spots,compared with the hydrocarbon generation unit.The migration paths include the one from mudstone/shale to siltstone interlayers and that from the high-TOC mudstone/shale intervals to the low-TOC intervals.The in-source accumulation of shale oil shows the differentiated enrichment model featuring“high-TOC mudstone/shale generating hydrocarbons,low-TOC mudstone/shale retaining hydrocarbons,siltstone accumulating hydrocarbons and multiple intra-source migration paths”.In the Ordos Basin,the organic-lean(TOC 1–3%)mudstone/shale intervals appear to be the sweet spots of shale oil,where there are abundant medium-short-chain hydrocarbons retained with high flowability.After fracturing stimulation,their production conditions may be even superior to those of siltstones.This proposed idea changes the previous strategy to look for sweet spots in high-TOC intervals derived from the shale gas industry.