Serum Prolactin Response to Stressors in Children. • 67

Abstract

To further describe the relationship between prolactin and behavior in children, sequential serum prolactins were obtained in the course of a follow-up study of iron deficiency in infancy. 167 of the original 191 Costa Rican children (87%) were assessed at 10-13 years of age (mean=12 yr); prolactins were available for 164 subjects. At the time of venipuncture for iron status measures, a catheter was placed indwelling for 4 hours to determine the initial rise and decline of prolactin with venipuncture (0, 15, 30 and 45 min) and prolactin response to a psychological task involving blindfolding, IQ testing, a socially stressful situation and routine dental examination (no fillings). Sera were separated, stored at - 20°C and later assayed by double-antibody RIA for prolactin. Using each child's lowest value as the reference for that child, IQ testing produced trivial changes in serum prolactin. In contrast, serum prolactin rose, on average, 34% after a socially stressful encounter, 62% after a dental exam and 177% after venipuncture. These responses all differed significantly from each other (p<0.1). Males had a greater increase than females after the dental exam (77% vs 39%, p<0.01) but there were no other gender differences. Serum prolactin response to physical or psychological stress has been inconsistently observed in previous studies. Addressing methodologic problems, this study used a larger sample, both genders, varying stressors, and sequential sampling immediately post-stressor. The results show that serum prolactin is a sensitive stress response hormone in children and the degree of the response appears related to the severity of the stressor.