Decreased vasopressin content in parvocellular CRH neurosecretory system of Lewis rats.
Rats possess stress-responsive, vasopressin (VP)-expressing and stress-nonresponsive, VP-deficient subpopulations of parvocellular corticotropin-releasing hormone (CRH) neurosecretory cells. Both subpopulations are activated by bacterial lipopolysaccharide (LPS) and cytokines. Lewis rats exhibit hyporesponsive hypothalamo-pituitary-adrenocortical axes (HPAAs). The Lewis CRH neurosecretory system has been reported to be defective in females and normal in males. We used post-embedding electron microscopic (EM) immunocytochemistry to study baseline levels and LPS-stimulated depletion of neurosecretory vesicles. Male Lewis rats possessed normal numbers of CRH+/VP- varicosities and low numbers of CRH+/VP+ varicosities, indicating abnormally low release of VP into portal blood. This defect contrasts with the reported increase in VP content and release in magnocellular neurosecretory cells in Lewis rats.
Whitnall
M H
MH
Department of Physiology, Armed Forces Radiobiology Research Institute, Bethesda, MD 20889-5603.
Anderson
K A
KA
Lane
C A
CA
Mougey
E H
EH
Neta
R
R
Perlstein
R S
RS
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D003346:Corticotropin-Releasing Hormone / Q000502:physiology*; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D007150:Immunohistochemistry; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D014667:Vasopressins / Q000378:metabolism*
D008070:Lipopolysaccharides; D014667:Vasopressins; D003346:Corticotropin-Releasing Hormone