| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Articles in PresS, published online ahead of print November 29, 2001
Am J Physiol Regu Physiol, 10.1152/ajpregu.00634.2001
Submitted on October 25, 2001
Accepted on November 23, 2001
1 Pediatrics, Research Institute GROW, Maastricht University, Maastricht, Netherlands
2 Pharmacology & Toxicology, Cardiovascular Research Institute Maastricht CARIM, Maastricht University, Maastricht, Netherlands
3 Physiology, University of Cambridge, Cambridge, United Kingdom
* To whom correspondence should be addressed. E-mail: amul{at}skin.azm.nl.
In response to an acute hypoxemic insult, the mammalian fetus shows a redistribution of the cardiac output in favor of heart and brain. Peripheral vasoconstriction contributes to this response and is partly mediated by the release of catecholamines. Two mechanisms of catecholamine release in the fetus are reported: 1) neurogenic sympathetic stimulation, and 2) non-neurogenic via a direct effect of hypoxemia on chromaffin tissues. In the present study the effects of sympathetic blockade were studied on plasma catecholamine release and cardiac output distribution in response to acute hypoxemia in the chick embryo at different stages of incubation. Only at the end of the incubation period sympathetic blockade markedly attenuated the increase in plasma catecholamine concentrations and resulted in a greater fraction of the cardiac output distributed to the carcass. However, these effects did not prevent a significant increase in cardiac output to the brain and heart during acute hypoxemia. These data imply that, in the chick embryo, the contribution of neurogenic mechanisms on the catecholaminergic response to acute hypoxemia becomes greater by the end of the incubation period.
This article has been cited by other articles:
|
|
 |
|
  L. Danielson, I. C. McMillen, J. L Dyer, and J. L Morrison Restriction of placental growth results in greater hypotensive response to {alpha}-adrenergic blockade in fetal sheep during late gestation J. Physiol., March 1, 2005; 563(2): 611 - 620. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Villamor, C. G. A. Kessels, K. Ruijtenbeek, R. J. van Suylen, J. Belik, J. G. R. De Mey, and C. E. Blanco Chronic in ovo hypoxia decreases pulmonary arterial contractile reactivity and induces biventricular cardiac enlargement in the chicken embryo Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2004; 287(3): R642 - R651. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Ruijtenbeek, J. G. R. De Mey, C. E. Blanco ;, and H. Ehmke The Chicken Embryo in Developmental Physiology of the Cardiovascular System: A Traditional Model with New Possibilities Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2002; 283(2): R549 - R551. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
