Effect of cesarean delivery on perioperative regulation of the beta-adrenergic receptor system of human lymphocytes.

Abstract

We studied the perioperative regulation of the beta-adrenergic receptor (beta AR) system in lymphocytes obtained before and after surgery from 12 patients undergoing cesarean delivery with spinal anesthesia. Receptor number (Bmax) and binding affinity (KD) were determined by Scatchard analysis of [125I]iodopindolol saturation binding curves. Receptor function was assessed by measuring cyclic adenosine 3',5'-monophosphate (cAMP) production in the unstimulated state and in response to stimulation by isoproterenol, forskolin, and prostaglandin E1. Basal cAMP production increased 48% postoperatively (P < 0.05), while stimulated cAMP production and Bmax and KD were not significantly changed after surgery. The response to surgery of the beta AR system on these patients differed from that of patients undergoing cardiothoracic and abdominal surgery in whom we previously found postoperative down-regulation and desensitization of the beta AR system. It is possible that this difference in response is due to amelioration of the stress response to surgery by regional anesthesia, and/or alterations in beta AR status by pregnancy. We conclude that pregnancy and regional anesthesia, but not changes in lymphocyte subset distribution, contributed to the lack of effect of surgery on the beta AR system in the patients studied.