Contents of corticotropin-releasing hormone and arginine vasopressin immunoreactivity in the spleen and thymus during a chronic inflammatory stress.
We have previously found that proopiomelanocortin (POMC) mRNA and levels of adrenocorticotropin (ACTH) and beta-endorphin peptides are increased in the spleen and thymus of rats with adjuvant-induced arthritis (AA), and immunologically mediated inflammatory disease. To determine whether alterations in immune tissue POMC during AA are also accompanied by changes in immune tissue corticotropin-releasing hormone immunoreactivity (ir-CHR) and arginine vasopressin (AVP), we measured ir-CRH and AVP by radioimmunoassays in spleen and thymic extracts 14 days following injection of adjuvant. Ir-CRH was detectable in all extracts of spleen and thymus. Total contents of ir-CRH in the spleen and thymus were not altered following arthritis, although a significant decrease was observed in splenic extracts from arthritis rats (40.0 +/- 4.2 fmol/g tissue) compared to controls (69.5 +/- 8.4 fmol/g tissue) when contents were expressed as amount per weight of tissue. Low levels of AVP were also detected in immune tissues, with contents significantly increased in spleens from arthritis animals (17.4 +/- 1.6 fmol/g tissue) compared to controls (10.6 +/- 1.9 fmol/g) but thymic contents of AVP were not altered by arthritis (10.6 +/- 1.3 fmol/g) compared to controls (9.2 +/- 0.7 fmol/g). Control levels of AVP were significantly higher in spleens and thymuses from female rats (53 +/- 5 and 25 +/- 4 fmol/g tissue, respectively) compared to males. G-50 chromatography revealed that the principal form of splenic ir-CRH is CRH(1-41), although in non-arthritic animals some ir-CHR eluted in a position indicating a slightly larger form.(ABSTRACT TRUNCATED AT 250 WORDS)
Chowdrey
H S
HS
Department of Medicine, University of Bristol, Bristol Royal Infirmary, UK.
Lightman
S L
SL
Harbuz
M S
MS
Larsen
P J
PJ
Jessop
D S
DS
D000818:Animals; D001127:Arginine Vasopressin / Q000032:analysis* / Q000276:immunology; D001169:Arthritis, Experimental / Q000378:metabolism*; D002908:Chronic Disease; D003346:Corticotropin-Releasing Hormone / Q000032:analysis* / Q000276:immunology; D005260:Female; D008297:Male; D011333:Pro-Opiomelanocortin / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000737:chemistry*; D013950:Thymus Gland / Q000737:chemistry*
D001127:Arginine Vasopressin; D011333:Pro-Opiomelanocortin; D003346:Corticotropin-Releasing Hormone