Active Immunization of Female Rats with Luteinizing Hormone Releasing Hormone (LHRH)

Active immunization of young ram lambs against testosterone and luteinizing hormone-releasing hormone (LHRH) was shown to block the growth attributes characteristic of intact ram lambs. Testosterone and LHRH-immunized lambs grew at a slower rate and converted feed to live weight gain less efficiently than albumin-immunized controls. Lambs immunized against testosterone and LHRH had high antibody titers for their respective antigens. Moreover, testosterone-immunized lambs had high serum concentrations of luteinizing hormone (LH) and testosterone, whereas LHRH-immunized lambs had low to nondetectable serum concentrations of these hormones. Release of LH and testosterone following the intravenous administration of LHRH (250 ng) was absent in LHRH-immunized lambs, but quantitatively similar for intact and albumin-immunized control lambs. Testosterone-immunized lambs responded as did conventional castrates with a large LH release, but testosterone concentrations were unchanged. These findings are discussed relative to the integrity of the hypothalamic-pituitary-testicular endocrine axis and the importance of gonadotropin support for normal testicular development. These data show that LHRH immunoneutralization effectively retards testicular development and produces a castration effect in young ram lambs.

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Luteinizing Hormone Releasing Hormone (LHRH) Neuronal Function in Middle-Aged Female Rats

Biology of Menopause ◽

10.1007/978-0-387-21628-7_2 ◽

2000 ◽

pp. 11-23

Author(s):

Beverly S. Rubin ◽

Mercedes Jimenez-Linan

Keyword(s):

Luteinizing Hormone ◽

Female Rats ◽

Neuronal Function ◽

Middle Aged ◽

Luteinizing Hormone Releasing Hormone ◽

Releasing Hormone

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SERUM LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE CONCENTRATIONS IN IMMATURE FEMALE RATS TREATED WITH MULTIPLE INJECTIONS AND VARIOUS AMOUNTS OF LUTEINIZING HORMONE RELEASING HORMONE

Journal of Endocrinology ◽

10.1677/joe.0.0660013 ◽

1975 ◽

Vol 66 (1) ◽

pp. 13-20 ◽

Cited By ~ 4

Author(s):

D. C. JOHNSON ◽

R. S. MALLAMPATI

Keyword(s):

Luteinizing Hormone ◽

Constant Stimulus ◽

Female Rats ◽

Intact Female ◽

Immature Female ◽

Luteinizing Hormone Releasing Hormone ◽

Releasing Hormone ◽

Serum Luteinizing Hormone ◽

Serum Lh ◽

Lh Rh

SUMMARY Release of immunoreactive LH and FSH was induced in immature intact female rats by repeated injections of synthetic luteinizing hormone releasing hormone (LH-RH). Altering the dose of LH-RH (5, 10, 20, 50 ng) and the frequency of administration (every 10, 20, 30 or 60 min) over a period of 2 h produced a variety of serum LH and FSH concentrations and ratios. When the dose was a constant 20 ng but the frequency of injections was either 20 or 30 min, a steady state in serum gonadotrophin concentrations was reached within 1 h and the level remained the same during the second hour. When given every 10 min, 20 ng LH-RH produced a much higher concentration of both LH and FSH during the second hour of stimulation. Examination of the gonadotrophin levels after each injection of LH-RH showed that the pituitary response was variable in spite of a constant stimulus.

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