抄録
Plasma human growth hormone (HGH) levels in normal subjects and patients with pituitary dysfunction were measured by the double antibody radioimmunoassay method of Schalch and Parker. The HGH standard (HS 705A) was kindly supplied by Dr. A. E. Wilhelmi.
Plasma HGH concentrations of normal subjects after overnight fasting were less than 5mμg/ml in most of the cases. There was no significant difference by sexes. Plasma HGH levels increased significantly after insulin-induced hypoglycemia (regular insulin, 0.1U/kg body weight) in normal subjects. The mean and standard deviation of the peak HGH levels was 42.6±16.6 mμg/ml after injection of insulin. Plasma HGH levels rose significantly following infusion of L-arginine (0.5g/kg body weight), with the mean peak value of 33.2±13.4mμg/ml in the normal subjects tested. Plasma HGH levels decreased slightly following oral administration of glucose.
Patients with hypopituitarism or pituitary dwarfism had low resting HGH levels as compared with control subjects or non-pituitary dwarfs, although a considerable overlap was noted between these groups. In all subjects with hypopituitarism or pituitary dwarfism, plasma HGH response to insulin-induced hypoglycemia or arginine infusion was either limited or absent. Primordial dwarfism was not associated with any significant abnormalities in HGH response to the stimuli used.
Three patients, two of which were siblings, appeared to have isolated growth hormone deficiency. Another patient, a 22-year-old male, was a sporadic case and showed partial sexual maturation. Patients with anorexia nervosa had rather elevated resting HGH levels which increased normally following hypoglycemia induced by insulin. These results indicate that determination of plasma HGH is useful for differential diagnosis of hypopituitarism from anorexia nervosa, pituitary dwarfism from other types of dwarfism and for diagnosis of isolated growth hormone deficiency.
In patients with acromegaly, plasma HGH levels were consistently elevated and did not fall following oral glucose administration to the same degree as that in normal subjects. Plasma HGH levels were either unchanged or significantly increased following hypoglycemia induced by insulin. Plasma HGH levels were determined in series in 5 patients with active acromegaly before, during and following transsphenoidal stereotactic cryohypophysectomy. Insertion of a cryoprobe into the sella turcica, biopsy of the pituitary mass and especially freezing procedure caused a rapid and significant rise in plasma HGH. Plasma HGH concentrations then declined gradually to a significantly lower level than before surgery. Both clinical manifestations and laboratory data were greatly improved after cryoablation of the pituitary gland, accompanied by normalization of plasma HGH. The course of a patient with gigantism was followed before, during and after the development of pituitary apoplexy. Following apoplexy, an acute reduction in plasma HGH was observed with the development of hypopituitarism. Plasma HGH assay is an useful mean for diagnosis of active acromegaly and evaluation of the treatment.
