Prolactin, the prolactin receptor and uncoupling protein abundance and function in adipose tissue during development in young sheep.
A primary role of the prolactin receptor (PRLR) during fetal and postnatal development has been suggested to be the regulation of uncoupling protein (UCP) expression. We, therefore, determined whether: (1) the rate of loss of UCP1 from brown adipose tissue after birth was paralleled by the disappearance of PRLR; and (2) administration of either pituitary extract prolactin (PRL) containing a mixture of posttranslationally modified forms or its pseudophosphorylated form (S179D PRL) improved thermoregulation and UCP1 function over the first week of neonatal life. PRLR abundance was greatest in adipose tissue 6 h after birth before declining up to 30 days of age, a trend mirrored by first a gain and then a loss of UCP1. In contrast, in the liver--which does not possess UCPs--a postnatal decline in PRLR was not observed. Administration of PRL resulted in an acute increase in colonic temperature in conjunction with increased plasma concentrations of non-esterified fatty acids and, as a result, the normal postnatal decline in body temperature was delayed. S179D PRL at lower concentrations resulted in a transient rise in colonic temperature at both 2 and 6 days of age. In conclusion, we have demonstrated a close relationship between the ontogeny of UCP1 and the PRLR. Exogenous PRL administration elicits a thermogenic effect suggesting an important role for the PRLR in regulating UCP1 function.
Pearce
S
S
Centre for Reproduction and Early Life, Institute of Clinical Research, Queen's Medical Centre, University Hospital, Nottingham, NG7 2UH, UK.
Budge
H
H
Mostyn
A
A
Genever
E
E
Webb
R
R
Ingleton
P
P
Walker
A M
AM
Symonds
M E
ME
Stephenson
T
T
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001833:Body Temperature Regulation / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism*; D003106:Colon / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D007473:Ion Channels; D008099:Liver / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D024101:Mitochondrial Proteins; D011388:Prolactin / Q000378:metabolism / Q000494:pharmacology*; D020033:Protein Isoforms / Q000378:metabolism / Q000494:pharmacology; D011981:Receptors, Prolactin / Q000378:metabolism*; D012756:Sheep / Q000254:growth & development* / Q000378:metabolism*; D000071256:Uncoupling Protein 1
D002352:Carrier Proteins; D005230:Fatty Acids, Nonesterified; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D020033:Protein Isoforms; D011981:Receptors, Prolactin; D000071256:Uncoupling Protein 1; D011388:Prolactin