Effect of some hormones on the lactate dehydrogenase (LDH) isoenzyme patterns of Holtzman rat mammary glands.

The effect of 17 beta-estradiol, testosterone propionate and haloperidol induced prolactin release in the lactate dehydrogenase (LDH) isoenzyme patterns of female Holtzman rat mammary tissues was investigated. The LDH pattern of the mammary gland of an adult female rat showed all five isoenzymes. One week following castration, a loss of muscle type LDH-5 isoenzyme was evident in such patterns. The administration of 17 beta-estradiol alone could restore the LDH-5 isoenzyme in the mammary tissues of such castrated females. It was therefore concluded that LDH-5 isoenzyme in the mammary glands of Holtzman rats is truly estrogen dependent.