Abstract
Little is known about the underlying mechanisms for the altered susceptibility to digitalis with age. To this end, we investigated the digoxin uptake and excretion in mice and rats of different ages through the life span, including the periods of growth, maturity, and aging. Digoxin uptake by cardiac slices was linear from 0 to 15 min, with steady state occuring at 45 min. The rate in the mature 12-month mouse was significantly less than that of the senescent 30-month mouse. The kinetic parameters revealed a significant decrease in Km with a concomitant increase in Vmax during senescense. On the other hand uptake by renal cortical slices was highest during growth, decreased to a maturation plateau and then declined further during senescence. Renal clearance and the secretory capacity for digoxin increased 30 and 62%, respectively, during growth and progressively decreased from maturity through senescence and were 59 and 77%, respectively, during aging. In summary, there was an increase in digoxin clearance and tubular activity during growth, and in increase in myocardial uptake of digoxin and a decrease in renal excretion during aging. Thus, these results may explain the clinical observations of altered susceptibility to digitalis with age.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
