ENDOTHELIN-1-LIKE IMMUNOREACTIVITY IN A NEW RODENT MODEL OF SPONTANEOUS HYPERTENSION

The purpose of this study was to determine plasma and tissue endotheli n-1 (ET-1)-like immunoreactivity in a new rodent model of spontaneous hypertension. Plasma and tissues were procured from pentobarbital-anes thetized 16- to 18-week-old male hamsters with spontaneous hypertensio n and genetically/age-matched normotensive hamsters. We found that ET- 1-like immunoreactivity in the plasma was similar in both groups. Howe ver, renal and cardiac ET-1-like immunoreactivity was 11- and 1.7-fold higher in spontaneously hypertensive hamsters relative to normotensiv e hamsters, respectively (P <.05). ET-1-like immunoreactivity was slig htly, but significantly, lower in the lung and spleen of spontaneously hypertensive hamsters relative to normotensive hamsters (P <.05). ET- 1-like immunoreactivity in the liver and brain was similar in both gro ups. We conclude that ET-l-like immunoreactivity is significantly high er in two target organs for hypertension, kidney and heart, but not in plasma or brain of adult male hamsters with spontaneous hypertension, relative to genetically/age-matched normotensive hamsters. We suggest that renal and cardiac ET-1 could play a role in the natural history of spontaneous hypertension in hamsters. Am J Hypertens 1998; 11:866-8 69 (C) 1998 American Journal of Hypertension, Ltd.