METABOLIC AND ENDOCRINE RESPONSES TO COLD-EXPOSURE IN CHRONICALLY INCUBATED EXTRAUTERINE GOAT FETUSES

Citation
N. Unno et al., METABOLIC AND ENDOCRINE RESPONSES TO COLD-EXPOSURE IN CHRONICALLY INCUBATED EXTRAUTERINE GOAT FETUSES, Pediatric research, 43(4), 1998, pp. 452-460
Citations number
38
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Pediatrics
Journal title
ISSN journal
0031-3998
Volume
43
Issue
4
Year of publication
1998
Pages
452 - 460
Database
ISI
SICI code
0031-3998(1998)43:4<452:MAERTC>2.0.ZU;2-Q
Abstract
To investigate developmental aspects of metabolic and endocrine respon ses to cold exposure in fetuses, we conducted experiments on six goat fetuses, three aged 95-116 d of gestation (dGA; group I), and three ag ed 122-134 dGA (group II), using an extrauterine fetal incubation syst em that provided arteriovenous extracorporeal membrane oxygenation (A- V ECMO). The fetuses were cannulated via the umbilical vessels, and th eir blood gas exchange was totally supported by A-V ECMO, while they w ere maintained in an isothermal incubator containing artificial amniot ic fluid. After confirming that fetuses were in metabolically stable c ondition in the extrauterine incubation system, fetal core temperature was lowered by 2 degrees C over 2 h by decreasing the temperature of incubating fluid from 39.5 degrees C. During and after cold exposure, fetal heart rate and arterial blood pressure remained unchanged. We ob served significant increases in oxygen consumption and plasma concentr ations of norepinephrine, epinephrine, adrenocorticotropic hormone, an d cortisol in group II but not in group I fetuses. In addition, based on regression analysis, maximal changes of these parameters during col d exposure were linearly correlated with gestational age significantly , and the regression lines were found to intersect the x (gestational age) axis at around 98-106 dGA. These results suggest that metabolic a nd endocrine responses to cold exposure develop with gestational age i n the goat fetus, the responses being manifested around 100 dGA.