Influence of Recipients’ Sex Differences on the Growth in Grafts after Rat Fetal Metanephros Transplantation
Author(s): Kotaro Nishi, Shozo Okano, Takashi Yokoo, Satomi Iwai
We have attempted a regeneration method to promote a kidney growth by transplanting a fetal metanephros with bladder (MNB) into the recipient’s body. In many studies regarding regeneration, males were used, but the development of treatment for chronic kidney disease must be considered regardless of sex in clinical practice. In this study, we transplanted two MNBs to male or female recipient rats and evaluated their growth. The first MNB (MNB1) was transplanted to male (n=12: male group) and female (n=14: female group) Lewis rats (Day 0). The morphology of MNB1 in every seven days was evaluated using ultrasonography, and the second MNB (MNB2) was transplanted on Day 28. On Day 56, all MNBs were collected and used for histopathological examination. The size of MNBs in the male group was significantly larger than that of the females on every measurement day (p<0.05). Furthermore, there were no marked changes in the volume of MNB1 in the female group on Day 28. In the male group, the ratio of urine retention of MNBs were significantly higher than that of the female group. Female MNBs were found the mononuclear cell infiltration and tubular atrophy in the histopathological examination. This study investigated MNBs transplanted to male or female rats over time, and clarified that the size and urine volume of MNBs in the male group were larger than those of the female. Therefore, we suggested that recipients’ sex differences have an influence on the growth in grafts after the rat fetal metanephros transplantation.