Relationship between serum prolactin and surgical insult - abstract

ABSTRACT

Prolactin is now known to be essential for normal immuno-competence. Hypophysectomized rats were shown to be severly immunocompromised with depressed antibody titters to administered antigents and virtually absent delayed hypersensitivity. Immunocompetence in these animals was restored by exogenous replacement of prolactin. Prolactin receptors have been demonstrated on T and B lymphocyte. In rats, the number of prolactin receptors per cell was similar for lymphocytes and the mammary glands. As a result of these observations we evaluated the relationship between surgical insult and serum prolactin levels. Patients And Methods: Twenty-one patients scheduled for various surgical procedures were chosen consecutively and studied prospectively. Patients who were pregnant or within 12 months postpartum or being treated with any medication affecting prolactin levels were eliminated from the study. Blood was drawn at around 8 a.m. on the day of surgery prior to the surgical procedure and on postoperative day 3 and day 5. Samples were assayed for prolactin and cortisol. Prolactin was measured by a chemoluminescene assay - Ciba corning. Cortisol was measured by radioimmunoassay incstar. The collected data were analyzed for statistical significance using an advanced analysis software S.P.S.S. for windows 6.0. Results: Twelve males and 9 females, mean age 55, were studied 6 patients had surgical procedures for non-malignant gastrointestinal disorders, 2 had carcinoma of the G.I. tract, 5 had acute cholecystitis, 4 had hernias repaired, 3 had femoral popliteal bypass and one had resection of parotid tumor. The prolactin and cortisol levels are shown as follows PROLACTIN [0-23.0 NG/ML] Pre-op, Post-op Day #3, Post-op Day #5 - mean 19.35, 25.0, 29.44 respectively; St. Dev.- 18..25, 20.28, 23.76 respectively; pValve -, <0.08, <0.038 respectively. CORTISOL [5.0 -25.0 UG/DL] - Pre-op, Post-op Day #3, Post-op Day#5- Mean 17.31, 17.66, 14.38 respectively, St, Deviation - 6.68, 5.89, 4.97 respectively; pvalve; -, <0.83, <0.09 respectively. Using the two tail test the mean prolactin level on postoperative day #5 compared to preoperative prolactin level showed a statistically significant change. p<0.038. Cortisol did not change significantly. CONCLUSION: Cortisol levels were not significantly elevated postoperatively. Thus the elevated prolactin levels cannot be attributed only to the stress of surgery. On the basis of these results we postulate that prolactin plays a significant role in the recovery process following surgical insult (AU)