Summary
Gonadotropin-releasing hormone (GnRH) agonists induce a clinically undesirable, transitory but very pronounced initial rise of gonadotropin and gonadal steroid secretion. We investigated, in a non-human primate model, whether the initial stimulatory effects of GnRH agonists can be avoided by a short period of pretreatment and simultaneous treatment with a GnRH antagonist. Three groups of five adult male cynomolgus monkeys (Macaca fascicularis) received a single s.c. biodegradable implant loaded with the GnRH agonist, buserelin ([D-Ser(TBu)6-desGly-NH2]-GnRH), releasing approximately 50 μg buserelin daily. From 1 week before to 1 week after inception of administration of GnRH agonist, group 1 received the GnRH antagonist vehicle, and groups 2 and 3 were given s.c. injections of the GnRH antagonist Nal-Glu ([Ac-D-Nal(2)1,D-4-Cl-Phe2, D-Pal3, D-Arg5,D-Glu6(AA),D-Ala10]-GnRH) at a dose of 450 or 2250 μg/kg daily. In the absence of GnRH antagonist, the GnRH agonist induced a marked elevation of serum luteinizing hormone (LH) and testosterone lasting for 2 and 5 days, respectively. In group 2, Nal-Glu reduced basal hormone secretion and delayed the peak of GnRH-agonist-induced hormone secretion by 1 day. In group 3, the GnRH-agonist-induced rise of LH and testosterone was prevented in three animals and did not exceed baseline hormone levels in the other two animals. Areas under the LH and testosterone curves were significantly reduced in group 3 compared to group 1. After withdrawal of the GnRH antagonist, a second transient rise of hormone secretion was observed. Except for testosterone in group 2, this rise did not exceed the baseline range of hormone concentrations. The study demonstrates that high doses of GnRH antagonist can prevent the GnRH agonist-induced initial rise of LH and testosterone secretion, while after withdrawal of the GnRH antagonist a second rise of hormone secretion occurs, which is less pronounced than with GnRH agoniit alone.
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Akhtar FB, Wickings EJ, Nieschlag E (1984) Male fertility control with an LH-RH agonist: primate studies. In: Vickery BH, Nestor JJ Jr, Hafez ESE (eds) LH-RH and its analogs. MTP Press, Lancaster, p 77
Behre HM, Nashan D, Hubert W Nieschlag E (1992) Depot gonadotropin-releasing hormone agonist blunts the androgeninduced suppression of spermatogenesis in a clinical trial of male contraception. J Clin Endocrinol Metab 74:84
Behre HM, Klein B, Steinmeyer E, Nieschlag E (1991) Effective suppression of luteinizing hormone and testosterone by single doses of the new gonadotropin-releasing hormone antagonist SB-75 in normal men. (Abstract 1155) 73rd Meeting of the Endocrine Society, p 319, Washington, June 18–22, 1991
Boccardo F (1990) Total androgen blockade: rationale and review of clinical experience. In: Bouchard P, Haour F, Franchimont P, Schatz P (eds) Recent progress on GnRH and gonadal peptides. Elsevier, Amsterdam, p 293
Boccon-Gibod L, Laudat MH, Dugue MA, Steg A (1986) Cyproterone acetate lead-in prevents initial rise of serum testosterone by luteinizing hormone-releasing hormone analogs in the treatment of metastatic carcinoma of the prostate. Eur Urol 12:400
Gibaldi M, Perrier D (1982) Pharmacokinetics, 2nd edn. Dekker, New York
Heber D, Dodson R, Swerdloff RS, Channabasavaiah K, Stewart JM (1982) Pituitary receptor site blockade by a gonadotropin-releasing hormone antagonist in vivo: mechanism of action. Science 216:420
Heber D, Dodson R, Peterson M, Channabasavaiah KC, Stewart JM, Swerdloff RS (1984) Counteractive effects of agonistic and antagonistic gonadotropin-releasing hormone analogs on spermatogenesis: sites of action. Fertil Steril 41:309
Jockenhövel F, Bhasin S, Steiner B, River JE, Vale WW, Swerdloff RS (1988) Hormonal effects of a single gonadotropinreleasing hormone antagonist dose in men. J Clin Endocrinol Metab 66:1065
Karten MJ, Rivier J (1986) Gonadotropin-releasing hormone analog design. Structure-function studies towards the development of agonists and antagonists: rationale and perspective. Endocr Rev 7:44
Loumaye E, Catt KJ (1983) Agonist-induced regulation of pituitary receptors for gonadotropin-releasing hormone. J Biol Chem 258:12002
Lunglmayr G (1988) Zoladex vs Zoladex plus flutamide in the treatment of advanced prostate cancer. First interim analysis of an international trial. In: Murphy GP, Khoury S (eds) Therapeutic progress in urological cancers. Liss, New York, p 1451
Marshall GR, Akhtar FB, Weinbauer GF, Nieschlag E (1986) Gonadotropin-releasing hormone (GnRH) overcomes GnRH antagonist induced suppression of LH secretion in primates. J Endrocrinol 110:145
Pavlou SN, Wakefield G, Schlechter NL, Lindner J, Souza KH, Kamilaris TC, Kondidaris S, Rivier JE, Vale WW, Toglia M (1989) Mode of suppression of pituitary and gonadal function after acute or prolonged administration of a luteinizing hormone-releasing antagonist in normal men. J Clin Endocrinol Metab 68:446
Pavlou SN, DeBold CR, Orth DN (1990) LHRH antagonist: clinical studies in man. In: Bouchard P, Haour F, Franchimont P, Schatz B (eds) Recent progress on GnRH and gonadal peptides. Amsterdam, Elsevier, p 195
Puente M, Catt KJ (1986) Inhibition of pituitary-gonadal function in male rats by a potent GnRH antagonist. J Steroid Biochem 25:917
Sandow J (1982) Inhibition of pituitary and testicular function by LHRH analogues. In: Jeffcoate SL, Sandler M (eds) Progress towards a male contraceptive. Wiley, Chicester, p 191
Sandow J (1983) Clinical applications of LHRH and its analogues. Clin Endocrinol 18:571
Santen RJ (1989) Hormonal therapy of prostate cancer: choosing among several available options. Int J Androl 12:165
Schmidt F, Sundaram K, Thau RB, Bardin CW (1984) [Ac-d-NAL(2)1, 4Fd-Phe2,d-Trp3,d-Arg6]-LHRH, a potent antagonist of LHRH, produces transient edema and behavioral changes in rats. Contraception 29:283
Schürmeyer T, Wickings EJ, Freischem CW, Nieschlag E (1983) Saliva and serum testosterone following oral testosterone undecanoate administration in normal and hypogonadal men. Acta Endocrinol 102:456
Swerdloff RS, Bhasin S, Salameh W, Tom L, Peterson M, Steiner B (1990) Combined GnRH antagonist and testosterone enanthate for experimental male contraception. (Abstract 35) Gynecol Endocrinol 4:28
Waxman J (1989) Short-term and anti-androgen therapy and very long-acting depot gonadotropin-releasing hormone agonist for prostatic cancer. In: Murphy GP, Khoury S (eds) Therapeutic progress in urological cancers. Liss, New York, p 61
Weinbauer GF, Nieschlag E (1985) Regulation of primate testicular function by GnRH analogues. Med Biol 63:210
Weinbauer GF, Göckeler E, Nieschlag E (1988) Testosterone prevents complete suppression of spermatogenesis in the gonadotropin-releasing hormone antagonist-treated nonhuman primate (Macaca fascicularis). J Clin Endocrinol Metab 67:284
Weinbauer GF, Jackwerth B, Yoon YD, Behre HM, Yeung CH, Nieschlag E (1990) Pharmacokinetics and pharmacodynamics of testosterone enanthate and dihydrotestosterone enanthate in non-human primates. Acta Endocrinol 122:432
Wickings EJ, Qazi MH, Nieschlag E (1979) Determination of biologically active LH in the serum of male rhesus monkeys. J Reprod Fertil 57:497
Wynn PC, Suarez-Quian CA, Childs GV, Catt KJ (1986) Pituitary binding and internalization of radioiodinated gonadotropin-releasing hormone agonist and antagonist ligands in vitro and in vivo. Endocrinology 119:1852
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Supported by the Deutsche Forschungsgemeinschaft, grant DFG Ni 130/11-A1
Recipient of an Alexander von Humboldt Research Fellowship
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Sharma, O.P., Weinbauer, G.F., Behre, H.M. et al. The gonadotropin-releasing hormone (GnRH) agonist-induced initial rise of bioactive LH and testosterone can be blunted in a dose-dependent manner by GnRH antagonist in the non-human primate. Urol. Res. 20, 317–321 (1992). https://doi.org/10.1007/BF00922743
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DOI: https://doi.org/10.1007/BF00922743