ACROMEGALIC GIGANTISM WITH LOW SERUM LEVEL OF GROWTH-HORMONE AND ELEVATED SERUM INSULIN-LIKE GROWTH-FACTOR-I

In a case of acromegalic gigantism with hyperprolactinemia is reported , the basal serum growth hormone (GH) levels ranged from 1.2 to 1.9 ng /ml. Serum GH response to either insulin-induced hypoglycemia or GH-re leasing hormone was blunted. Frequent blood sampling showed non-pulsat ile GH secretion. Serum prolactin and insulin-like growth factor-I (IG F-I) levels were elevated. After unsuccessful surgery, bromocriptine t reatment normalized serum prolactin without affecting serum GH and IGF -I levels. Combined administration of octreotide with bromocriptine re duced serum GH and IGF-I levels. In this case, non-pulsatile GH secret ion and enhanced tissue sensitivity to GH may induce hypersecretion of IGF-I and cause clinical acromegalic gigantism.