Prolonged suppression of plasma LH levels in male rats after a single injection of an LH-RH agonist in poly(DL-lactide-co-glycolide) microcapsules.

R. H. Asch, F. J. Rojas, A. Bartke, Andrew V Schally, T. R. Tice, H. G. Klemcke, T. M. Siler-Khodr, R. E. Bray, M. P. Hogan

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

The authors have examined the effects of a subcutaneous injection of the LH-RH agonist D-Trp6-LH-RH formulated in biodegradable poly(DL-lactide-co-glycolide) microcapsules on plasma levels of D-Trp6LH-RH, LH, and PRL in adult, gonadectomized male rats. Immunoreactive D-Trp6-LH-RH was detectable in the plasma of these animals at 1, 2, 3, and 4 weeks after injection. LH concentrations were greatly reduced 1 week after administering the D-Trp6-LH-RH microcapsule, continued to decrease during the following week, and remained suppressed until the end of the study, 6 weeks after the injection. Plasma PRL levels appeared elevated 1 to 2 weeks after the injection and suppressed thereafter, but these effects were significant only in animals rendered hyperprolactinemic by transplantation of an isologous pituitary under the renal capsule. These results demonstrate that an LH-RH agonist formulated in biodegradable microcapsules and administered as a subcutaneous injection can exert marked biologic effects in rats for at least 6 weeks. These findings also suggest that prolonged exposure to an LH-RH agonist may first produce stimulation, followed by an inhibition of PRL release from both in situ and ectopic pituitaries.

Original languageEnglish
Pages (from-to)83-88
Number of pages6
JournalJournal of Andrology
Volume6
Issue number2
StatePublished - Mar 1 1985
Externally publishedYes

Fingerprint

Polyglactin 910
Gonadotropin-Releasing Hormone
Capsules
Injections
Subcutaneous Injections
poly(lactide)
Transplantation
Kidney

ASJC Scopus subject areas

  • Endocrinology

Cite this

Prolonged suppression of plasma LH levels in male rats after a single injection of an LH-RH agonist in poly(DL-lactide-co-glycolide) microcapsules. / Asch, R. H.; Rojas, F. J.; Bartke, A.; Schally, Andrew V; Tice, T. R.; Klemcke, H. G.; Siler-Khodr, T. M.; Bray, R. E.; Hogan, M. P.

In: Journal of Andrology, Vol. 6, No. 2, 01.03.1985, p. 83-88.

Research output: Contribution to journalArticle

Asch, RH, Rojas, FJ, Bartke, A, Schally, AV, Tice, TR, Klemcke, HG, Siler-Khodr, TM, Bray, RE & Hogan, MP 1985, 'Prolonged suppression of plasma LH levels in male rats after a single injection of an LH-RH agonist in poly(DL-lactide-co-glycolide) microcapsules.', Journal of Andrology, vol. 6, no. 2, pp. 83-88.
Asch, R. H. ; Rojas, F. J. ; Bartke, A. ; Schally, Andrew V ; Tice, T. R. ; Klemcke, H. G. ; Siler-Khodr, T. M. ; Bray, R. E. ; Hogan, M. P. / Prolonged suppression of plasma LH levels in male rats after a single injection of an LH-RH agonist in poly(DL-lactide-co-glycolide) microcapsules. In: Journal of Andrology. 1985 ; Vol. 6, No. 2. pp. 83-88.
@article{47290ccad2be42be9d52a8da7f377cbb,
title = "Prolonged suppression of plasma LH levels in male rats after a single injection of an LH-RH agonist in poly(DL-lactide-co-glycolide) microcapsules.",
abstract = "The authors have examined the effects of a subcutaneous injection of the LH-RH agonist D-Trp6-LH-RH formulated in biodegradable poly(DL-lactide-co-glycolide) microcapsules on plasma levels of D-Trp6LH-RH, LH, and PRL in adult, gonadectomized male rats. Immunoreactive D-Trp6-LH-RH was detectable in the plasma of these animals at 1, 2, 3, and 4 weeks after injection. LH concentrations were greatly reduced 1 week after administering the D-Trp6-LH-RH microcapsule, continued to decrease during the following week, and remained suppressed until the end of the study, 6 weeks after the injection. Plasma PRL levels appeared elevated 1 to 2 weeks after the injection and suppressed thereafter, but these effects were significant only in animals rendered hyperprolactinemic by transplantation of an isologous pituitary under the renal capsule. These results demonstrate that an LH-RH agonist formulated in biodegradable microcapsules and administered as a subcutaneous injection can exert marked biologic effects in rats for at least 6 weeks. These findings also suggest that prolonged exposure to an LH-RH agonist may first produce stimulation, followed by an inhibition of PRL release from both in situ and ectopic pituitaries.",
author = "Asch, {R. H.} and Rojas, {F. J.} and A. Bartke and Schally, {Andrew V} and Tice, {T. R.} and Klemcke, {H. G.} and Siler-Khodr, {T. M.} and Bray, {R. E.} and Hogan, {M. P.}",
year = "1985",
month = "3",
day = "1",
language = "English",
volume = "6",
pages = "83--88",
journal = "Journal of Andrology",
issn = "0196-3635",
publisher = "American Society of Andrology Inc.",
number = "2",

}

TY - JOUR

T1 - Prolonged suppression of plasma LH levels in male rats after a single injection of an LH-RH agonist in poly(DL-lactide-co-glycolide) microcapsules.

AU - Asch, R. H.

AU - Rojas, F. J.

AU - Bartke, A.

AU - Schally, Andrew V

AU - Tice, T. R.

AU - Klemcke, H. G.

AU - Siler-Khodr, T. M.

AU - Bray, R. E.

AU - Hogan, M. P.

PY - 1985/3/1

Y1 - 1985/3/1

N2 - The authors have examined the effects of a subcutaneous injection of the LH-RH agonist D-Trp6-LH-RH formulated in biodegradable poly(DL-lactide-co-glycolide) microcapsules on plasma levels of D-Trp6LH-RH, LH, and PRL in adult, gonadectomized male rats. Immunoreactive D-Trp6-LH-RH was detectable in the plasma of these animals at 1, 2, 3, and 4 weeks after injection. LH concentrations were greatly reduced 1 week after administering the D-Trp6-LH-RH microcapsule, continued to decrease during the following week, and remained suppressed until the end of the study, 6 weeks after the injection. Plasma PRL levels appeared elevated 1 to 2 weeks after the injection and suppressed thereafter, but these effects were significant only in animals rendered hyperprolactinemic by transplantation of an isologous pituitary under the renal capsule. These results demonstrate that an LH-RH agonist formulated in biodegradable microcapsules and administered as a subcutaneous injection can exert marked biologic effects in rats for at least 6 weeks. These findings also suggest that prolonged exposure to an LH-RH agonist may first produce stimulation, followed by an inhibition of PRL release from both in situ and ectopic pituitaries.

AB - The authors have examined the effects of a subcutaneous injection of the LH-RH agonist D-Trp6-LH-RH formulated in biodegradable poly(DL-lactide-co-glycolide) microcapsules on plasma levels of D-Trp6LH-RH, LH, and PRL in adult, gonadectomized male rats. Immunoreactive D-Trp6-LH-RH was detectable in the plasma of these animals at 1, 2, 3, and 4 weeks after injection. LH concentrations were greatly reduced 1 week after administering the D-Trp6-LH-RH microcapsule, continued to decrease during the following week, and remained suppressed until the end of the study, 6 weeks after the injection. Plasma PRL levels appeared elevated 1 to 2 weeks after the injection and suppressed thereafter, but these effects were significant only in animals rendered hyperprolactinemic by transplantation of an isologous pituitary under the renal capsule. These results demonstrate that an LH-RH agonist formulated in biodegradable microcapsules and administered as a subcutaneous injection can exert marked biologic effects in rats for at least 6 weeks. These findings also suggest that prolonged exposure to an LH-RH agonist may first produce stimulation, followed by an inhibition of PRL release from both in situ and ectopic pituitaries.

UR - http://www.scopus.com/inward/record.url?scp=0022032221&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0022032221&partnerID=8YFLogxK

M3 - Article

C2 - 3157667

AN - SCOPUS:0022032221

VL - 6

SP - 83

EP - 88

JO - Journal of Andrology

JF - Journal of Andrology

SN - 0196-3635

IS - 2

ER -