DESENSITIZATION OF NEUROTENSIN-INDUCED PHOSPHOINOSITIDE HYDROLYSIS INTRANSFECTED CHO CELLS

The regulation of neurotensin-induced phosphoinositide turnover was st udied in transfected CHO cells expressing the rat neurotensin receptor . Stimulation of these cells with neurotensin resulted in an important , but transient, increase in inositol phosphate cell content. Preincub ation of the cells with neurotensin dramatically decreased their respo nse to further stimulation. This diminution, which was rime-dependent and not related to the availability of phospholipase C substrate, is t hough to reflect a progressive homologous desensitization of the recom binant neurotensin receptor.