Artery wall substance P in the goldblatt hypertensive rat

Innervation of the artery wall includes the sensor} neuropcptide substance I (SP) in unmyelinaled. afferent C-typc fibers. Because these nerves may con tri hüte to blood pressure control, we examined the impact of hypertension upon SP in the aorta and superior mesentcric artery iSMA) using the two-kidney, one clip Goldblatt model (H) and sham operated control (C) nits (n=5 each). Eight weeks alter renal artery constriction, ihc SMA, thoracic and abdominal aorta segments were excised for determinations of SP by RIA. Hypertension was indicated by systolic BP sustained at > 140 mmlig. significantly enlarged hearts 11.54 vs 1.20 g. P < 0.015) and increased heart/body weigh! ratios [3.Xd vs. 2 75 i\ 10 '). P < 0.04|. Final body weights were not significantly different between groups iP = 0.32). SP contents (fmol/mg tissue, mean t s.e.) of H vs. C groups were significantly greater in the SMA (9.95 ± 1.4V vs. 6.27 ±0.51, P < 0.02) and thoraeic'aorta (0.31 1 0.05 vs. 0.18 0.05. P < 0.05). Mean SP content was increased in the abdominal aorta f the H group 11.I ±0.1 h vs. 0.97 ±0.15), hut did not attain statistical gnificancc. These findings indicate that in addition to changes of letaholic. structural, compositional and physiological parameters noted ith sustained hypertension, elevated levels of the sensor)- neuropeptide SP also develop in the rat artery wall. Funded m part by NIH award HL 42593-01 and Organized Research of NAU.