Role of Pituitary LH and Placenta in Luteal Progesterone Production and Maintenance of Pregnancy in the Rat

  • H. G. Madhwa Raj
  • L. M. Talbert
  • W. E. Easterling
  • Ruth Chen Dy
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 112)


It is now well-established that neutralization of circulating LH using specific antiserum leads to termination of pregnancy in the rat (1–3). In our extensive investigations, we demonstrated that LH antiserum is effective when administered from day 1–8 or any day between 8 and 11 (1,3). Neutralization of LH is effective even at midnight of day 11, but not at 10 a.m. on day 12, indicating a sharp ‘cut off’ point. The observed termination of pregnancy is accompanied by profuse vaginal bleeding 36 to 48 hrs after antiserum administration. Plasma progesterone levels drastically fall within a short period of neutralizing LH (4). This indicates that LH is essential for production of progesterone at this time of pregnancy. The effects of LH antiserum on pregnancy have been amply confirmed by other investigators (5–7). Morishige and Rothchild (5) extended these studies to earlier period of pregnancy and demonstrated that LH dependency sets in between day 6 and 8, simultaneously with the loss of dependency on pituitary prolactin. To investigate the mode of action of LH, Gibori et al utilized the LH antiserum treated rat model system (8). They demonstrated that testosterone implants can maintain pregnancy, in such rats. Further Gibori and Keyes have provided significant evidence that testosterone administered is converted to estrogen, which in turn maintains progesterone production in the pregnant rat. The rat corpus luteum contains high concentrations of estrogens during pregnancy (9, 10) and exogenous estrogen stimulates luteal growth and progesterone secretion in hypophysectomized-hysterectomized pregnant rats (11, 12). Intraovarian bursal estrogen implants also seem to maintain luteal functionality as judged by progesterone secretion, during days 10 and 11 of pregnancy (13). Thus at the present time it seems that the luteal progesterone production becomes dependent on pituitary LH and placental luteotropin by day 8 of pregnancy. The present series of investigations were undertaken to elucidate the contribution of the placenta and its potential to sustain steroidogenesis in the absense of LH.


Progesterone Production Luteal Function Progesterone Secretion Synthetic Progestin Serum Progesterone Level 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. (1).
    H.G. Madhwa Raj and N.R. Moudgal. Endocrinology 86(1970)874.CrossRefGoogle Scholar
  2. (2).
    K.K. Loewit, S. Badawy and K.A. Laurence. Endocrinology 84(1969)244.PubMedCrossRefGoogle Scholar
  3. (3).
    H.G. Madhwa Raj, M.R. Sairam and N.R. Moudgal. Jour.Reprod. Fertil. 17(1968)335.CrossRefGoogle Scholar
  4. (4).
    N.R. Moudgal, H.R. Behrman and R.O. Creep. J.Endocrinol. 52(1972)413.PubMedCrossRefGoogle Scholar
  5. (5).
    W.K. Morishige and I. Rothchild. Endocrinology 95(1974)260.PubMedCrossRefGoogle Scholar
  6. (6).
    J. Akaka, E. O’Laughlin-Phillips and I. Rothchild. Endocrinology 100 (1977) 1334.PubMedCrossRefGoogle Scholar
  7. (7).
    M.R. Sairam and C.H. Li in: Hormonal Proteins and Peptides, Vol. 1, ed. C.H. Li ( Academic Press, New York, 1973 ) p. 101.Google Scholar
  8. (8).
    G. Gibori, P.L. Keyes and J.S. Richards. Proc.9thAnn.Meet. Soc.Stud.Reprod. (1976) p. 39.Google Scholar
  9. (9).
    H.B. Waynforth and D.M. Robertson. J.Endocrinol. 54(1972)79.PubMedCrossRefGoogle Scholar
  10. (10).
    D.J. Elbaum and P.L. Keyes. Endocrinology 99(1976)573.PubMedGoogle Scholar
  11. (11).
    M. Takayama and G.S. Greenwald. Endocrinology 92 (1973) 1405.PubMedCrossRefGoogle Scholar
  12. (12).
    G. Gibori and P.L. Keyes. Endocrinology 102(1978) 1176.PubMedCrossRefGoogle Scholar
  13. (13).
    G. Gibori, R. Rodway and I. Rothchild. Endocrinology 101(1977) 1683.PubMedCrossRefGoogle Scholar
  14. (14).
    G.J. Macdonald, N.R. Moudgal, H.G. Madhwa Raj and R.O. Greep. Proc.Soc.Exp.Biol.Med. 144(1973)923.PubMedGoogle Scholar
  15. (15).
    V. Larsson-Cohn, E.D.B. Johansson, L. Wide and C. Gemzell. J.Obst.Gynecol.British.Commwlth. 77(1970)840.CrossRefGoogle Scholar
  16. (16).
    E.D.B. Johansson. ActaEndocrinol. 68(1970)779.Google Scholar
  17. (17).
    E.B. Astwood and R.O. Greep. Proc.Soc.Exp.Biol.Med. 38(1938)713.Google Scholar
  18. (18).
    F.G. Haour and P. Sanchez. C.R.Acad.Sci. 282(1976) 1183.Google Scholar
  19. (19).
    J. Clemens, M. Sar and J. Meites. Proc.Soc.Exp.Biol.Med. 130(1969)628.PubMedGoogle Scholar
  20. (20).
    E.S. Kisch and M.C. Schelesnyak. Jour.Reprod.Fertil. 15(1968)401.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1979

Authors and Affiliations

  • H. G. Madhwa Raj
    • 1
    • 2
  • L. M. Talbert
    • 1
  • W. E. Easterling
    • 1
  • Ruth Chen Dy
    • 1
  1. 1.Division of Reproductive Endocrinology and Fertility Departments of Obstetrics and GynecologyUniversity of North Carolina School of MedicineChapel HillUSA
  2. 2.Division of Reproductive Endocrinology and PharmacologyUniversity of North Carolina School of MedicineChapel HillUSA

Personalised recommendations