Secretion of luteinizing hormone (LH) and its beta-subunit (LH-beta) by luteinizing hormone-releasing hormone (LH-RH) were studied in perifused rat anterior pituitary cells. LH release was dose related between 10(-10) and 10(-6)M LH-RH. Every 5-minute pulse of 10(-8)M LH-RH induced almost similar response to the initial LH release; neither the self-priming effect nor desensitization were significant. Continuous administration of 10(-8)M LH-RH caused an initial LH release, followed by distinct desensitization, which could not be overcome by subsequent pulses of 10(-8)M LH-RH. The results were quite similar in LH-beta release. The perifusion study is shown to be useful in analyzing the characteristics of LH and LH-beta release, and the present results suggest that LH-RH receptor-mediated regulation may be also involved in LH-beta release.