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Changes in the responsiveness of hypothalamic prokineticin 2 mRNA expression to food deprivation in developing female rats
Author(s) -
Iwasa Takeshi,
Matsuzaki Toshiya,
Munkhzaya Munkhsaikhan,
Tungalagsuvd Altankhuu,
Kawami Takako,
Murakami Masahiro,
Yamasaki Mikio,
Kato Takeshi,
Kuwahara Akira,
Yasui Toshiyuki,
Irahara Minoru
Publication year - 2014
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2014.02.001
Subject(s) - endocrinology , medicine , appetite , hypothalamus , period (music) , neuropeptide y receptor , messenger rna , biology , neuropeptide , gene expression , gene , receptor , biochemistry , physics , acoustics
Prokineticin 2 (PK2) is highly expressed in several regions of the central nervous system, including the hypothalamus. Recently, it has been suggested that PK2 plays a role in appetite regulation. In adult male rodents, the administration of PK2 decreased food intake, and PK2 mRNA expression was reduced by food deprivation. Usually, the changes in the expression levels of appetite‐regulating factors induced in response to fasting are not fully established during the neonatal period. Thus, we investigated the developmental changes in hypothalamic PK2 mRNA expression and the alterations in hypothalamic PK2 mRNA expression induced by fasting during the pre‐pubertal period in female rats. The changes in hypothalamic neuropeptide Y (NPY) mRNA expression were also examined because NPY is a potent appetite regulatory factor. Hypothalamic PK2 mRNA expression was extremely high during the early neonatal period (postnatal day (PND) 5) compared with that observed during subsequent periods (PND15, 25, and 42), while hypothalamic NPY mRNA expression did not differ among any of the examined periods. A fasting‐induced reduction in hypothalamic PK2 mRNA expression was observed on PND5, but no fasting‐induced increase in hypothalamic NPY mRNA expression was seen during the same period. In addition, the fasting‐induced reduction in hypothalamic PK2 mRNA expression observed on PND5 was more marked than that seen on PND25. These results suggest that the sensitivity of hypothalamic PK2 expression to undernutrition develops during the early neonatal period, when the responses of other appetite regulatory factors to such pressures remain immature.