title: Direct measurement of allantoic blood flow in the chicken, Gallus domesticus. Responses to alteration in ambient temperature and PO2.
abstract: A technique is described for direct measurement of allantoic blood flow in chicken embryos in situ using an electromagnetic flow meter. A branch of the allantoic artery was catheterized non-obstructively for simultaneous pressure measurement. In 15-day-old embryos at 39 degrees C the mean heart rate was 278 beats/min falling to 124 beats/min at 26 degrees C. Despite this fall in heart rate, blood flow fell only 10% from 4.4 ml/min at 39 degrees C to 4.0 ml/min at 26 degrees C. Mean allantoic blood pressure was similarly nearly unaffected by temperature. Allantoic blood flow was insignificantly altered by hyperoxic as well as hypoxic exposure (6% O2).
authors.forename: H
authors.initials: H
authors.lastname: Tazawa
authors.forename: J P
authors.initials: JP
authors.lastname: Lomholt
authors.forename: K
authors.initials: K
authors.lastname: Johansen
mesh_terms: D000482:Allantois / Q000098:blood supply*; D000818:Animals; D001794:Blood Pressure; D002642:Chick Embryo; D005321:Extraembryonic Membranes / Q000098:blood supply*; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure; D012039:Regional Blood Flow; D013696:Temperature
chemical_list: D010100:Oxygen