Influence of route of delivery and ambient temperature on thermoregulation in newborn lambs.
Am J Physiol
; 272(6 Pt 2): R1931-9, 1997 Jun.
Article
em En
| MEDLINE
| ID: mdl-9227610
ABSTRACT
We examined the effect of route of delivery on brown adipose tissue (BAT) function and thermoregulation in lambs born either vaginally at term or by cesarean section close to term. Immediately after birth, lambs were placed in a warm (30 degrees C; WD) or cool (15 degrees C; CD) ambient temperature, and measurements of colonic temperature, plus heat production (i.e., oxygen consumption and carbon dioxide production), were recorded for 6 h. Over the first 30 min of life, colonic temperature remained constant in vaginally delivered lambs and was lower in the WD group. Following cesarean section delivery, colonic temperature declined rapidly, a response that was greater in the CD group. Cesarean section-delivered lambs had an increased reliance on shivering thermogenesis and restored colonic temperature after 2 h, and by 6 h these parameters were higher than in lambs born vaginally. Irrespective of delivery, temperature, plasma thyroid hormone concentrations and norepinephrine content of BAT were lower in lambs born by cesarean section compared with those born vaginally. Plasma cortisol concentrations and epinephrine content of BAT were greater in lambs born by cesarean section. The amount of uncoupling protein and level of guanosine 5'-diphosphate binding in BAT were higher in vaginally delivered than in cesarean section-delivered lambs, and for each group mean values were greater for CD than WD lambs. Cesarean section delivery results in altered thyroidal, adrenal, and sympathetic activity, which appears to have a marked influence on BAT function, thereby contributing to distinct differences in thermoregulation compared with lambs born vaginally.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Temperatura
/
Regulação da Temperatura Corporal
/
Parto Obstétrico
/
Meio Ambiente
/
Animais Recém-Nascidos
Limite:
Animals
/
Pregnancy
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Reino Unido