The physiological and molecular responses of granulosa cells (GCs) from buffalo follicles were investigated when there were in vitro heat stress conditions imposed. The cultured GCs were heat-treated at 40.5 °C for 24, 48 or 72 h while GCs of the control group were not heat-treated (37 °C). There were no differences in viability between control and heat-treated groups. There was an upward trend in increase in E₂ secretion as the duration of heat stress advanced, being greater (P ≤ 0.05) for the GCs on which heat stress was imposed for 72 as compared with 24 h. In contrast, P₄ release was less (P ≤ 0.05) from GCs heat-treated for 48 h than those cultured for 24 h and GCs of the control group. The relative abundance of ATP5F1A and SOD2 mRNA transcripts was consistent throughout the period when there was imposing of heat stress to sustain mitochondrial function. The relative abundance of CPT2 transcript was less in heat-treated GCs than in GCs of the control group. There was a greater relative abundance of SREBP1 and TNF-α mRNA transcripts after 48 h of heat-treatment of GCs than GCs of the control group. In conclusion, the results from the current study indicate buffalo GCs cultured when there was imposing of heat stress maintained normal viability, steroidogenesis and transcriptional profile. The stability of antioxidant status and increased transcription of genes regulating cholesterol biosynthesis and stress resistance may be defense mechanisms of buffalo GCs against heat stress.

当存在体外热应激条件时，研究了来自水牛卵泡的颗粒细胞 (GC) 的生理和分子反应。培养的GCs在40.5°C下热处理24、48或72小时，而对照组的GCs未热处理（37°C）。对照组和热处理组之间的生存力没有差异。随着热应激持续时间的延长，E ₂分泌增加呈上升趋势，与24小时相比，施加热应激72小时的GCs更大（P ≤ 0.05）。相比之下，P ₄释放较少（P≤ 0.05）来自热处理48小时的GCs比培养24小时的GCs和对照组的GCs。在施加热应激以维持线粒体功能的整个时期内，ATP5F1A和SOD2 mRNA 转录物的相对丰度是一致的。CPT2转录本的相对丰度在热处理的 GC 中低于对照组的 GC。SREBP1和TNF-α 的相对丰度更高GCs热处理48小时后的mRNA转录本高于对照组的GCs。总之，当前研究的结果表明，在施加热应激时培养的水牛 GCs 保持了正常的活力、类固醇生成和转录特征。抗氧化状态的稳定性和调节胆固醇生物合成和抗逆性基因转录的增加可能是水牛 GC 抵御热应激的防御机制。