The effect of age on the biliary transport maximum (Tm) of bile salts in rats.
Age-related differences in the biliary transport maxima (Tm) values for taurocholate (TC) and tauroursodeoxycholate (TUDC) were examined in female Fischer-344 rats as well as Wistar-derived rats of both sexes. The Tm values for TUDC were more than two times higher than corresponding values for TC in young (3-month-old) rats of both sexes. Tm values for both bile salts tended to decline with age, demonstrating a significant negative correlation between the Tm (micromol/min per g liver) and rat age (months) for all rat groups. The decline in Tm value was, however, dominant in the first year with little significant change after 1 year. The results in the present study coupled with our previous observations for Tm values of sulfobromophthalein (BSP) and conjugated BSP support our hypothesis that the transport capacity for bile canalicular membrane generally declines with age in rats.
Kanai
S
S
Department of Clinical Physiology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakatecho, Itabashi-ku, Tokyo, Japan.
Sato
Y
Y
Kitani
K
K