The development of renal hypertension in the rat.

The investigation was undertaken in an attempt to provide a more simple animal model for studying renal hypertension in the rat. Rats were surgically altered by two procedures, single nephrectomy and single nephrectomy plus encapsulation, the latter completed in a common operation. Systolic blood pressure was observed at various intervals of 14, 30, and 60 days. Systolic blood pressure was also observed at an 80 day interval in a control group. The results are as follows: Untreated Control - Systolic blood pressure was not significantly altered over an 80 day interval; Single Nephrectomy - Systolic blood pressure was not significantly altered at the 14, 30, or 60 day intervals (one animal died in this group immediately after surgery); Single Nephrectomy and Encapsulation - Of the 18 animals in this group 5 had significantly elevated systolic blood pressure by the 14 day interval, 1 became hypertensive by the 60 day interval, 6 showed no significant effect on systolic blood pressure, and 6 animals succumbed. Necropsies on the 6 animals which had no effect showed that the encapsulation procedure had failed.