Upregulation of synapsin IIa and IIb mRNAs in the paraventricular and supraoptic nuclei in chronic salt loaded and lactating rats.
The effects of chronic salt loading (2% saline to drink for 5 and 10 days), gestation, lactation and adrenalectomy on the expression of synapsin IIa and IIb genes were examined in the rat paraventricular (PVN) and supraoptic nuclei (SON), using in situ hybridization histochemistry. In each control, synapsin IIa and IIb genes were moderately expressed in the magnocellular division of the PVN and SON, while few transcripts of synapsin IIa and IIb were observed in the parvocellular division of the PVN. Chronic salt loading, gestation on day 21 and lactation on day 10 caused significant increases in synapsin IIa and IIb transcripts in the magnocellular division of the PVN and SON, compared to each control. Although corticotropin-releasing hormone transcripts in the parvocellular division of the PVN were significantly increased in the adrenalectomized rats, no changes in the transcripts of synapsin IIa and IIb were observed throughout the PVN. These results suggest that physiological stimuli such as osmotic challenge and lactation potently increase synapsin IIa and IIb mRNAs in the magnocellular neurons of the PVN and SON.
Department of Physiology, School of Medicine, University of Occupational and Evironmental Health, Kitaykyushu, Japan.
M
M
Nomura
Y
Y
Ueta
R
R
Serino
Y
Y
Yamamoto
I
I
Shibuya
H
H
Yamashita
D000315:Adrenalectomy; D000818:Animals; D005260:Female; D007774:Lactation / Q000502:physiology*; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism*; D011247:Pregnancy; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000494:pharmacology*; D013495:Supraoptic Nucleus / Q000378:metabolism*; D016704:Synapsins / Q000235:genetics*; D013997:Time Factors; D015854:Up-Regulation
D020033:Protein Isoforms; D012333:RNA, Messenger; D016704:Synapsins; D012965:Sodium Chloride