These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Contraception with LHRH agonists, a new physiological approach.
    Author: Labrie F, Séguin C, Bélanger A, Lefebvre FA, Massicotte J, Kelly PA, Pelletier G, Reeves JJ, Lemay A, Cusan L, Raynaud JP.
    Journal: Reproduccion; 1981; 5(4):229-41. PubMed ID: 6274723.
    Abstract:
    The paradoxical antifertility effects of luteinizing hormone releasing hormone (LHRH) agonists in experimental male and female animals have been reported. Treatment with LHRH induces luteolysis and inhibits ovulation in normal women; in men, the same treatment decreases testicular steroidogenesis. This paper examines the mechanisms responsible for the paradoxical antifertility effects of LHRH agonists. A series of experiments was conducted in rats to determine the following: 1) the effect of lower and more physiological doses of the LHRH agonist on testicular gonadotropin receptors, 2) the time course of the effect of daily administration of 1 mcg of LHRH agonist on testicular and plasma concentration of steroid intermediates, 3) cellular changes occurring in the testis during longterm administration of the agonist, and 4) characteristics of LHRH receptors in the testis. The results show that LHRH agonists: 1) produce an inhibiting effect on testicular prolactin receptor concentrations, 2) can cause a dramatic fall in testicular androstenedione and testosterone concentration following treatment, 3) induce degenerative cellular changes in rat testis during longterm administration, and 4) may play a role in the physiological control of gonadal functions by a locally produced LHRH-like molecule. Similar experiments on the ovarian functions in female rats show that relatively low doses of LHRH agonist leads to marked loss of ovarian LH (luteinizing hormone) receptor accompanied by a decreased plasma progesterone concentration and uterine weight. The presence of specific ovarian LHRH receptors raises the possibility that LHRH secreted locally could be involved in the control of ovarian activity. In 6 normal men, a single intranasal administration of a potent LHRH agonist clearly showed inhibition of testicular steroidogenesis while studies on the luteolytic and antiovulatory activity in normal women demonstrated a luteolytic action of LHRH and its agonists. Progesterone secretion from the corpus luteum is important for the implantation and the maintenance of early pregnancy. The intranasal route of administration of LHRH agonists offers the advantage of easy, routine application by the general population.
    [Abstract] [Full Text] [Related] [New Search]