Different blood pressure responses to opioids in three rat hypertension models: role of the baseline status of sympathetic and renin-angiotensin systems

Opioids interact with sympathetic and renin-angiotensin systems in control of arterial pressure (MAP). Our earlier finding that biphalin, a synthetic enkephalin analogue, decreased MAP in anaesthetized spontaneously hypertensive rats (SHR) prompted us to further explore this action, to get new insights into pathogenesis of various forms of hypertension. Biphalin effects were studied in SHR, uninephrectomized rats on high-salt diet (HS/UNX), and rats with angiotensin-induced hypertension (Ang-iH). Beside MAP, renal and iliac blood flows (RBF, IBF) and vascular resistances were measured. In anaesthetized and conscious SHR biphalin, 300 Îźg h-1kg-1 i.v., decreased MAP by ~10 and ~20 mmHg, respectively (PThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author