Effect of pituitary tumor MtT-F4 on carnitine levels in the serum,liver and heart of rats

Implantation of MtT-F4 tumor, a pituitary tumor that secretes large quantities of proclactin, growth hormone and ACTH, enhanced total liver carnitine 9-fold without alteration of the esterified to free carnitine ratio. This ratio increased and the concentration of free and total carnitine decreased in the serum of tumor bearing rats. Cardiac carnitine decreased (23%) when expressed on per unit organ weight but showed an increase on per 100 g body weight basis because of marked cardiac hypertrophy. Besides indicating that lipolytic products of pituitary affect liver carnitine, these results show that hyperlipidemia and fatty livers can exist at times despite elevation of liver carnitine content.