Endocrinology, Vol 120, 1027-1032, Copyright © 1987 by Endocrine Society
Cyclic hormonogenesis in gray collie dogs: interactions of hematopoietic and endocrine systems
CD Lothrop Jr, PA Coulson, HL Nolan, B Cole, JB Jones and WL Sanders
Cortisol, ACTH, T4, and T3 concentrations were determined in six cyclic
hematopoietic (CH) dogs to determine if hormonal cycles were a feature of
this hematopoietic disorder. It was determined that there were 12- to
14-day cycles of these hormones in CH dogs. Plasma cortisol and ACTH
concentrations peaked 4-8 days after the onset of neutropenia and were
concurrent with peak neutrophil counts. The peak ACTH concentration
occurred 1-2 days before or concurrent with the cortisol peak
concentration. T4 and T3 peak concentrations were opposite the cortisol
cycles, and maximal concentrations were seen when cortisol levels were
lowest. ACTH, GH-releasing factor and TRH response tests were performed in
the CH dogs. No frank deficiencies in hormone production were seen with the
ACTH, GH-releasing factor, and TRH responses in CH dogs relative to those
in normal dogs. It was concluded that cyclic hormonogenesis is a central
feature of CH disease. These findings are the first demonstration of
extrahematopoietic system cyclicity in this rare disease and suggest the
presence of common regulatory factors in the hematopoietic and endocrine
systems.
