The cell population of somatostatin and growth hormone-releasing factor using quantitative immunohistochemistry in the isolated GH deficient dwarf rat.
We examined the cell population of somatostatin (SS) in the periventricular nucleus (PN) and growth hormone-releasing factor (GRF) in the arcuate nucleus (ARC) between spontaneous dwarf rats (SDRs; gene symbol: dr), which show isolated GH deficiency, and normal rats using avidin-biotin complex (ABC) immunohistochemistry. The total number of SS perikarya per brain weight in the PN of SDRs was 824.8 +/- 49.6 (mean +/- S.E.M., n = 4), whereas that of controls was 1108.5 +/- 50.1 (n = 4). The GRF perikarya per brain weight in the ARC of SDRs numbered 1281.0 +/- 26.0 (n = 7), as compared to 685.4 +/- 64.6 (n = 7) in the controls. The SS perikarya in the PN of SDRs were significantly reduced (P less than 0.05), while the GRF perikarya in the SDRs were significantly increased (P less than 0.01). These results suggest that GH itself acts on SS to positively regulate its secretion and on GRF in a negative regulatory manner.
Sakuma
S
S
Department of Pediatrics, Jikei University School of Medicine, Tokyo, Japan.
Ishikawa
H
H
Okuma
S
S
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D007150:Immunohistochemistry; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011922:Rats, Mutant Strains / Q000378:metabolism*; D013004:Somatostatin / Q000378:metabolism*
D013004:Somatostatin; D013007:Growth Hormone-Releasing Hormone