TY - JOUR T1 - TOLERANCE TO THE VASCULAR EFFECTS OF GLYCERYL TRINITRATE JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 98 LP - 102 VL - 171 IS - 1 AU - P. NEEDLEMAN Y1 - 1970/01/01 UR - http://jpet.aspetjournals.org/content/171/1/98.abstract N2 - Tolerance to the blood pressure response of glyceryl trinitrate (GTN) was produced by administration of high doses of GTN three times a day (s.c.). The induction of tolerance was found to be time- and dose-dependent and was reversible with time upon withdrawal from GTN pretreatment. The tolerance phenomenon was present in vascular smooth muscle removed from GTN-treated animals but could not be induced in aorta strips in vitro. There was a parallel shift in the responsiveness of blood pressure and thoracic aorta strip preparations to challenging doses of GTN during tolerance development. On the other hand, tolerance was not produced in uterus or ileum strips from animals treated in vivo with GTN, even though these tissues are normally responsive to GTN. © 1970, by The Williams & Wilkins Company ER -