Diabetes patients are at a high risk of developing complications related to angiopathy and disruption of the signal transduction system. The liver is one of the multiple organs damaged during diabetes. Few studies have evaluated the morphological effects of adhesion factors in diabetic liver. The in uence of diurnal variation has been observed in the expression and functioning of adhesion molecules to maintain tissue homeostasis associated with nutrient uptake. The present study demonstrated that the rhythmin uenced functioning of tight junction was impaired in the liver of ob/ob mice. The tight junctions of hepatocytes were loosened during the dark period in normal mice compared to those in ob/ob mice, where the hepatocyte gaps remained open throughout the day. The time-dependent expression of zonula occludens 1 (ZO1) in the liver plays a vital role in the functioning of the tight junction. The timedependent expression of ZO1 was nulli ed and its expression was attenuated in the liver of ob/ob mice. ZO1 expression was inhibited at the mRNA and protein levels. The expression rhythm of ZO1 was found to be regulated by heat shock factor (HSF)1/2, the expression of which was reduced in the liver of ob/ob mice. The DNA-binding ability of HSF1/2 was decreased in the liver of ob/ob mice compared to that in normal mice. These ndings suggest the involvement of impaired expression and functioning of adhesion factors in diabetic liver complications.