Regulation of Hypothalamic Neuropeptide Y Messenger Ribonucleic Acid Expression during Lactation: Role of Prolactin

Nov 18, 2003Endocrinology

How prolactin controls brain signals that regulate appetite during breastfeeding

AI simplified

GLP-1 Therapies on OpenScience ↗PubMed ↗DOI ↗

Abstract

Suckling for 24 hours led to a significant increase in neuropeptide Y (NPY) mRNA levels in the dorsomedial nucleus of the hypothalamus (DMH) and the caudal portion of the arcuate nucleus (ARH-C).

Bromocriptine treatment reduced the increase of NPY mRNA in the DMH but did not affect the ARH.
Injections of ovine prolactin in bromocriptine-treated rats restored NPY mRNA levels in the DMH without affecting the ARH.
NPY-positive neurons in the DMH expressed prolactin receptor mRNA, while few NPY neurons in the ARH did.
These findings suggest that prolactin may directly influence NPY gene expression in DMH neurons during lactation.
NPY neurons in the DMH and ARH appear to be differentially regulated by prolactin during the lactation period.

AI simplified

In the present study, we investigated the role of prolactin (PRL) in the suckling-induced increase in hypothalamic neuropeptide Y (NPY) gene expression in the dorsomedial nucleus of the hypothalamus (DMH) and the caudal portion of the arcuate nucleus of the hypothalamus (ARH-C). Lactating rats were deprived of their eight-pup litters on d 9 postpartum. After 48 h, the animals were randomly divided into two groups: nonsuckled controls and eight pups suckling for 24 h. In addition, some of the suckled animals received two injections of bromocriptine (0.5 mg/rat per injection) to inhibit suckling-induced PRL secretion. Some bromocriptine-treated rats also received ovine PRL (1 mg/rat per injection). In situ hybridization was performed to measure NPY mRNA levels. Suckling for 24 h induced a significant increase in NPY mRNA levels in the DMH and ARH-C. Bromocriptine treatment greatly attenuated the increase of NPY mRNA in the DMH but not in the ARH. Injections of ovine PRL in bromocriptine-treated rats greatly restored DMH NPY mRNA levels but had no additional effects on the ARH NPY expression. Double-label in situ hybridization for NPY and PRL receptor (PRL-R) in the lactating rat brains showed that NPY-positive neurons in the DMH also express PRL-R mRNA. On the contrary, few ARH NPY neurons expressed PRL-R. These data suggest that PRL could act directly on DMH NPY neurons to modulate NPY gene expression during lactation. Thus, the results from the present study demonstrate that NPY neurons in the DMH and ARH are differentially regulated by PRL during lactation.

Full Text

Full text is available at the source.

View full text ↗

Regulation of Hypothalamic Neuropeptide Y Messenger Ribonucleic Acid Expression during Lactation: Role of Prolactin

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the glp-1 therapies brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the glp-1 therapies brief