Chronic measurement, using a Doppler probe, of uterine artery flow in the gravid guinea-pig.
A chronic animal model is described which permits for the first time the continuous measurement of uterine artery blood flow velocity in the pregnant guinea-pig by using a miniaturized Doppler flow probe. Preliminary validation revealed that alterations in actual blood flow are directly and proportionally related to the change in the Doppler shift (r = 0.984) from 0 to 100 ml/h. The velocity signal baseline was as stable as that of systemic blood pressure. Depending upon the individual animal's flow velocity, a deviation of 2-5% from baseline was statistically significant. With experience, greater than 90% of preparations were successful and a 30-day interval was often available for study. Uterine artery flow velocity increased steadily between 45 and 55 days of gestation. Instrumentation did not result in fetal growth retardation. A reduction in flow velocity occurred during general anaesthesia using ketamine and the antianxietal xylazine. In agreement with the reports of other investigators using a different model, both hydralazine and angiotensin II increased uterine blood velocity and adrenaline reduced it.
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects / Q000662:veterinary; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006830:Hydralazine / Q000494:pharmacology; D008954:Models, Biological; D011247:Pregnancy; D011270:Pregnancy, Animal; D014463:Ultrasonography; D014599:Uterus / Q000098:blood supply*
D000804:Angiotensin II; D006830:Hydralazine; D004837:Epinephrine