Hypotension preferentially induces c-fos immunoreactivity in supraoptic vasopressin neurons.
Immunoreactivity to Fos protein (Fos-IR) was detected in rat hypothalamic neurons within 1 h of onset of hemorrhage by withdrawing 4-5 ml of blood, which lowered the arterial blood pressure to 50-70 mm Hg. About 70% of vasopressin (AVP)-containing neurons in the supraoptic nucleus (SON) and 20% in the paraventricular nucleus (PVN) expressed Fos-IR. In contrast, 5% of oxytocin (OXY)-containing neurons in the SON and < 1% in PVN were Fos-IR. Intravenous infusion of the vasodilating agent, nitroprusside, which lowered the blood pressure to levels comparable to that attained by hemorrhage, induced Fos-IR in greater than 65% of AVP-containing neurons in the SON, while relatively few AVP neurons in the PVN were Fos positive. These results suggest that hemorrhage or hypotension preferentially induces c-fos expression in supraoptic AVP-containing neurons.
Shen
E
E
Department of Anatomy, Medical College of Ohio, Toledo 43699.
Dun
S L
SL
Ren
C
C
Bennett-Clarke
C
C
Dun
N J
NJ
D000818:Animals; D001127:Arginine Vasopressin / Q000032:analysis; D016762:Genes, fos; D007022:Hypotension / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D009599:Nitroprusside / Q000494:pharmacology*; D010121:Oxytocin / Q000032:analysis; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013495:Supraoptic Nucleus / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology
D016760:Proto-Oncogene Proteins c-fos; D001127:Arginine Vasopressin; D009599:Nitroprusside; D010121:Oxytocin