The foetoplacental unit and the initiation of lactation in the rat.

Rats were either Caesarean-sectioned, ovariohysterectomized or ovariectomized on day 19 of gestation and the role of prolactin and corticosteroids in the initiation of lactation was studied by administering 2-bromo-alpha-ergocryptine (CB 154) and prolactin, and by using adrenalectomy and foetectomy. The concentrations of corticosteroids and prolactin in the plasma and the weight and lactose content of the inguinal mammary glands were determined 48 h after Caesarean section, and 24 h after ovariohysterectomy and ovariectomy. The ranges in concentrations of corticosteroids, prolactin and mammary lactose were 207-348 micrograms/l plasma, 21.

Progressive changes in plasma progesterone, prolactin and corticosteroid levels during late pregnancy and the initiation of lactose synthesis in the rat.

The relationship between progesterone, prolactin, corticosteroids and corticosteroid binding globulin (CBG) activity in plasma and the initiation of lactation were studied in normal parturient rats, and rats either ovariohysterectomized or Caesarean-sectioned on day 19 of gestation. In chronically cannulated rats the decline in plasma progesterone to low values (less than 10 micrograms/l) in normal parturient rats 20 h before term and in Caesarean-sectioned rats 10-14 h after surgery was closely related to an increase in plasma prolactin. However, in ovariohysterectomized rats the levels of progesterone declined abruptly to 20 micrograms/l within 30 min of surgery and prolactin remained low (5 micrograms/l) for 4-8 h and then gradually increased during the subsequent 16-18 h.

Progesterone control of the initiation of lactose synthesis in the rat.

The in vitro incorporation of [14c]glucose into lactose in mammary tissue, the concentration of lactose in the mammary tissue and the concentration of lactose in the mammary secretion were determined during late pregnancy and lactation in the rat. These changes were related to the decline in blood progesterone during late pregnancy. The incorporation of [14C]glucose into lactose was detected on day 20 of pregnancy; it increased gradually until day 22 and then increased rapidly just prior to term (day 23 of pregnancy) to reach mean +/- s.

Periadenitis mucosa necrotica recurrens.

A review of the literature and a case report of PMNR that lasted more than 20 years is presented. The previously unreported use of large doses of erythromycin taken orally as a treatment alternative is offered.