Evaluation of blood pressure measurement using a miniature blood pressure transmitter with jacketed external telemetry in cynomolgus monkeys.
BACKGROUND
Current techniques used to accurately determine arterial blood pressure (BP) in conscious, unrestrained monkeys require invasive telemetry. This study evaluated the functionality of an implanted miniature telemetry blood pressure transmitter for the collection of BP measurements in conjunction with electrocardiographic measurements using a jacketed external telemetry (JET) system in conscious, unrestrained cynomolgus monkeys.


METHODS
Twenty-four animals were surgically implanted with the transmitter in the right femoral artery. Local tolerability to the implant, signal quality, and variability in hemodynamic values were evaluated. On alternate weeks, animals were given single doses of positive control agents to produce hypotensive (clonidine hydrochloride) or hypertensive (L-NAME) effects. Undisturbed telemetry BP data were continuously collected for at least 24h following dosing and analyzed.


RESULTS
While exhibiting remarkably high signal quality ( approximately 95% data points retained over 24h of data collection) and moderate variability across study weeks in baseline pulse height measurements (changes as small as < 0 mmHg), nine of 18 transmitters were nonfunctional by 19 weeks post-surgery, most likely due to migration of the catheter out of the artery. In animals given positive control agents, L-NAME induced a statistically significant increase (> or = + 8 mmHg) and clonidine hydrochloride induced a statistically significant decrease (-11 mmHg) in mean arterial pressures. Histological analysis revealed femoral arterial thickening near the sites of implantation.


CONCLUSIONS
These results demonstrate the ability of the miniature BP transmitter, in conjunction with the JET system, to detect small changes in hemodynamic data continuously collected in conscious unrestrained monkeys. Future optimization of the transmitter includes the addition of a suture rib to the transmitter body and increased catheter size to prevent catheter migration out of the artery, the root cause of failed transmitters. The miniature blood pressure transmitter evaluated provides a minimally invasive technique for continuous collection of hemodynamic data in a toxicology study environment.
McMahon
Carrie
C
Covance Laboratories Inc., 3301 Kinsman Boulevard, Madison, WI 53704-2595, USA. carrie.mcmahon@covance.com
Mitchell
Andrea Z
AZ
Klein
Jessica L
JL
Jenkins
Angela C
AC
Sarazan
R Dustan
RD
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001774:Blood Chemical Analysis / Q000662:veterinary; D001794:Blood Pressure / Q000187:drug effects*; D015924:Blood Pressure Monitors; D002320:Cardiovascular Physiological Phenomena; D057785:Catheters / Q000662:veterinary; D003000:Clonidine / Q000494:pharmacology; D003243:Consciousness; D004562:Electrocardiography / Q000662:veterinary; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D020007:Implants, Experimental / Q000662:veterinary; D008252:Macaca fascicularis; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D013686:Telemetry / Q000662:veterinary
D000959:Antihypertensive Agents; D004791:Enzyme Inhibitors; D003000:Clonidine; D019331:NG-Nitroarginine Methyl Ester