Y chromatin and estrogen.

Abstract

Introduction.It has been shown that X chromatin in nuclei derived from female infants is relatively less frequent during the first day of life while increases to adult frequency by about the fifth day.1~,2> Further, the evidence has been presented that Y chromatin in the newborn male nuclei is significantly lower in frequency at the first day of birth than in adults, but it increases to adult frequency during the neonatal period.3},4) Furthermore, we know that the lower frequency of X chromatin in neonates seems to occur in association with certain hormonal activities5~ : The frequency of X chromatin in nuclei of the cells of the parturient decreases within 24 hrs before and during 1-2 days after delivery. Some investigations were undertaken by us in order to inquire into the cause of the decrease in incidence of Y chromatin during the neonatal period in male infants, basing on the supposition that any relationship might be present between the lower incidence of Y chromatin during the neonatal period and the estrogen-level in newborn males, since an information is available indicating that the estrogenlevel in code blood is extremely high and then rapidly decreases after birth." with a hope to ascertain the relationship between the frequency of Y chromatin positive cells in adult males and the estrogenlevel, an examination was made with special regard to the transition of Y chromatin positive cells in adult males undergoing continuous medical treatments with estrogens after castration.Materials and methods. Blood smears were prepared from 22 adult males who have been receiving continuous therapy with estrogens after castration due to prostate cancer. Their mean age was 72.5±7.0 years and the term of therapeutic treatment ranged from three months to 12 years. Further, 22 normal adult males who had received no hormonal therapy during the near past provided blood samples for control. The mean age of the controls was 64.4±7.9 years.The subject of our observation deals with the occurrence and frequency of fluorescent bodies in lymphocytes derived from both