A Comparison of Pituitary Cells from Lean and Obese Zucker Rats

Abstract

Pituitary cells were isolated from lean and obese Zucker rats and compared with the use of 2 approaches. The 1st approach was to evaluate the capacity of an equal number of pituitary cells to stimulate growth in hypophysectomized rats. The rats implanted with lean pituitary cells grew at a similar rate as rats implanted with obese pituitary cells. Body composition was also determined to be similar in those rats receiving lean and obese rat pituitary cells. The 2nd approach was to evaluate the in vitro secretory capacity of rat pituitary cells when placed in a superfusion system. Basal and stimulated growth hormone release was the same for lean and obese rat pituitary cells. Apparently, the low level of serum growth hormone found in the Zucker obese rat is the result of a hypothalamic disorder and not a pituitary cell defect.