Lack of evidence for the participation of tonin in the pathogenesis of one-kidney, one-clip renovascular hypertension

Abstract

It has been reported that immunization against tonin normalizes blood pressure, and that sialoadenectomy, during which the tonin-rich salivary glands are removed, decreases blood pressure in one-kidney, one-clip hypertension. To investigate the role of tonin on this form of hypertension further, we actively immunized one-kidney, one-clip hypertensive rabbits with tonin and measured both the blood pressure response and the titer of antibodies raised against tonin. In addition, because sialoadenectomy may alter food intake, we assessed the effect of sialoadenectomy on the blood pressure of one-kidney, one-clip hypertensive rats fed a liquid diet to facilitate eating. After immunization, all rabbits developed antitonin-antibody titers ranging from 1:300 to 1:56,000. However, in none of the rabbits did the blood pressure decrease significantly (114 ± 3 mm Hg before immunization; 129 ± 6 mm Hg at 16 weeks after immunization). In one-kidney, one-clip hypertensive rats, sialoadenectomy did not lower blood pressure (179 ± 5 mm Hg before sialoadenectomy; 202 ± 9 mm Hg 3 weeks after sialoadenectomy). Neither blood pressure nor body weight differed between sialoadenectomy and sham-sialoadenectomy one-kidney, one-clip hypertensive rats (n = 6). In conclusion, neither active immunization against tonin in one-kidney, one-clip hypertensive rabbits nor sialoadenectomy in one-kidney, one-clip hypertensive rats significantly reduced established hypertension. These results do not support the hypothesis that tonin is involved in the pathogenesis of one-kidney, one-clip hypertension in these animal models.