POLYMORPHONUCLEAR NEUTROPHIL GRANULOCYTE CHEMOTACTIC HYPERRESPONSIVENESS IN A CASE OF CANINE ACROMEGALY

Growth hormone (GH) has recently been shown to affect polymorphonuclea r neutrophil granulocyte (PMN) function and to be secreted by mononucl ear cells, indicating that the hormone may be active in an immunophysi ologic network, acting as an endo- or paracrine priming agent. The pur pose of the present study was to evaluate the chemotactic responsivene ss of canine peripheral PMN in a dog with acromegaly, caused by sponta neous, progesterone-induced hypersecretion of GH and, secondary to thi s, a seven-fold increase in insulin-like growth factor I (IGF-I). The chemotactic responsiveness towards zymosan-activated serum (ZAS) and l eukotriene B4 (LTB4) was evaluated at a time when the dog suffered fro m acromegaly and again 57 days after corrective surgery (ovariohystere ctomy). The experiments showed that PMN from the patient exhibited enh anced chemotactic migration that appeared to be associated with the hy persomatotropic condition as judged from the reversibility of the phen omenon. The glucose intolerance and elevated serum alkaline phosphatas e that were observed in the acromegalic dog were also shown to be reve rsible following surgery.