Ovary-Independent Estrogen Receptor Expression: DISCUSSION(1)

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The results indicate clearly that OVX at birth did not affect porcine uterine growth or endometrial morphogenesis between birth and PND 60. Thus, uterine growth and endometrial development during this period are ovary-independent phenomena. In contrast, uterine growth from PND 60 to PND 120 is ovary dependent. Results are consistent with those reported by Wu and Dziuk, indicating that OVX of gilts on PND 20 did not affect uterine growth until after PND 60, when uteri of intact controls were larger and grew more rapidly. In contrast to gross patterns of uterine growth, endometrial adenogenesis proceeded during the period from birth to PND 120 in the absence of ovaries. Thus, while ovarian factors are eventually required to support normal uterine growth between birth and PND 120, there is no absolute requirement for ovarian support of mechanisms regulating transformation of the neonatal porcine endometrium from an infantile, glandless state at birth to the structurally mature, intensely glandular state characterized as occurring during this period. buy asthma inhalers

Ovary-independent uterine growth and development of endometrial glands were also reported for the neonatal ewe, as well as for the mouse and rat. That uterine histogenesis proceeds normally in OVX, adrenal-ectomized mice was interpreted to indicate that early postnatal development of the uterine wall occurs in an autonomous, developmentally programmed, steroid-independent manner. Studies of the neonatal rat showed that uterine growth is ovary and adrenal independent before PND 10. OVX alone, on PND 6, as well as OVX combined with adrenalectomy, delayed endometrial adenogenesis, but did not prevent it. It was suggested that, after PND 10, uterine growth in the rat is first partially (PND 11-15) and then completely (after PND 16) dependent on ovarian and, to a lesser extent, adrenal support.