Maternal adaptations to pregnancy in spontaneously hypertensive rats: leptin and ghrelin evaluation.
Leptin and/or ghrelin, initially thought to be considered messengers of energy metabolism, are now considered to play a role in normal and complicated pregnancy. In this study, pregnant, spontaneously hypertensive rats (SHR) have been used to evaluate, for the first time, the modification of leptin and ghrelin both at serum and tissue levels. In SHR, we evaluate plasma leptin level and tissue protein expression in both placenta and adipose tissue at the end of gestation (day 20) versus normotensive Wistar-Kyoto (WKY) animals. The expression of functional leptin receptor (Ob-Rb) in peripheral tissues and in the hypothalamus was evaluated. Moreover, we measured plasma ghrelin level and its mRNA expression in the stomach and placenta. SHR strain presented significantly lower plasma leptin levels when compared with those found in pregnant or not WKY controls. Interestingly, in the placenta, leptin gene expression was higher in SHR than normotensive WKY. Moreover, we demonstrated a resistance to the effects of leptin via 'downregulation' of hypothalamic receptors in pregnant SHR. Conversely, SHR presented significantly higher ghrelin plasma levels when compared with those found in pregnant or not WKY. However, we observed that ghrelin level in the stomach of SHR did not change during pregnancy, and on the opposite, mRNA ghrelin in the placenta of SHR was lower than that of normotensive rats, suggesting a different production of this hormone in the fetal-placental unit. These data gain further insight into metabolic hormone modifications observed in a model of pre-existing hypertension associated with pregnancy.
Raso
Giuseppina Mattace
GM
Department of Experimental Pharmacology, University of Naples, Federico II, via D. Montesano, 49-80131 Naples, Italy.
Bianco
Giuseppe
G
Iacono
Anna
A
Esposito
Emanuela
E
Autore
Giuseppina
G
Ferrante
Maria Carmela
MC
Calignano
Antonio
A
Meli
Rosaria
R
D000222:Adaptation, Physiological; D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D005260:Female; D015870:Gene Expression; D054439:Ghrelin / Q000032:analysis / Q000097:blood* / Q000235:genetics; D006973:Hypertension / Q000378:metabolism*; D007031:Hypothalamus / Q000737:chemistry; D020738:Leptin / Q000032:analysis / Q000097:blood*; D023421:Models, Animal; D009765:Obesity / Q000378:metabolism; D010920:Placenta / Q000737:chemistry; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D054411:Receptors, Leptin / Q000032:analysis / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013270:Stomach / Q000737:chemistry
D054439:Ghrelin; D020738:Leptin; D012333:RNA, Messenger; D054411:Receptors, Leptin