Effects of telemetry implantation surgery on blood pressure and its underlying mechanism.

OBJECTIVE: This study aimed to investigate the effects of radio-telemetry implantation surgery on blood pressure (BP) and renin-angiotensin-aldosterone system (RAAS), calcitonin gene-related peptide (CGRP) and endothelin-1 (ET-1) in rats.

METHODS: Six spontaneously hypertensive rat (SHRs) and six WKY rats successfully implanted telemetry were used as experimental group, while six SHRs and six Wistar-Kyoto (WKY) rats of comparable age, weight and BP free from implantation surgery were used as normal control group. BP in each group was monitored using the tail cuff method; furthermore, the content of PRA-I, PRA-II, ALD and ET-1, CGRP in plasma was measured with the ELISA.

RESULTS: After implantation surgery, there was no general strain difference in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in either SHRs or WKY rats. But there was a significant increase in renin and a suppression of the difference in angiotensin and aldosterone in SHRs and WKY rats. CGRP, ET-1 showed an overall decrease in SHRs and WKY rats.

CONCLUSION: These results indicated that although radio-telemetry is regarded as an efficient and reliable technology for measuring BP, we must pay attention to the influence of the operation itself on BP regulators. After the implantation surgery, decrease in arterial BP or decrease in circulating blood volume might stimulate the secretion of renin, and with the increase of BP and local blood flow, the level of CGRP was decreased. And the decrease of ET-1 may be a kind of protective suppression.