Prolactin response to severity of surgical insult

We previously showed that prolactin levels are significantly elevated during the recovery process from surgical insult, implying a role for prolactin in the neuroendocrine immune network. Our present study investigates the importance of severity of surgical insult to the prolactin response. Two groups of surgical patients were studied: 7 patients scheduled for "clean" elective surgery, herniorrhaphy and laparoscopic cholecystectomy, were compared to 7 patients scheduled for prolonged abdominal exploration. Patients who were pregnant or immediate postpartum or on medications affecting prolactin levels were not studied. Blood was drawn for prolactin and cortisol at 8:00 a.m. on the day of surgery prior to the procedure and on postoperative days 1,3 & 5. Prolactin was measured by a chemiluminescence assay (CIBA Corning, NY). Cortisol was measured by radioimmunoassay (INCSTAR). An advanced analysis software SPSS for Windows 6.0 was used to analyze the collected data. The "clean" surgery group consisted of 4 females and 3 males, mean age 51.5 years. The "prolonged" surgery group consisted of 5 males and 2 females, mean age 61.0 years. Using the two tailed test prolactin levels on post operative days 3 & 5 showed statistically significant increased compared to pre-operative levels in the prolonged surgery group. The "clean" surgery group showed no statistically significant changes in prolactin concentration. Cortisol levels were not significantly elevated in either group. The prolactin response to surgery is related to the severity of surgical insult. We postulate that the prolactin response correlates with the magnitude of the immune response.(AU)

Relationship between serum prolactin and surgical insult - 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)