A selective monotropic elevation of FSH, but not that of LH, amplifies the proliferation and differentiation of spermatogonia in the adult rhesus monkey (Macaca mulatta)  

Oleh:

Simorangkir, D.R. ; Ramaswamy, S. ; Marshall, G.R.

Jenis: Article from Journal - ilmiah internasional
Dalam koleksi: Human Reproduction vol. 24 no. 07 (Jul. 2009), page 1584-1595.
Topik: spermatogenesis/primate/testis/testicular clamp/FSH

Ketersediaan

Perpustakaan FK Nomor Panggil: H07.K.2009.03 Non-tandon: 1 (dapat dipinjam: 0) Tandon: tidak ada

Lihat Detail Induk

Isi artikel

BACKGROUND: Unilateral orchidectomy in monkeys increases spermatogenesis in the remaining testis in association with elevated follicle-stimulating hormone (FSH) secretion and testicular testosterone. The present study examined the relative importance of FSH and testosterone in driving the primate testis toward its spermatogenic ceiling. METHODS: Adult male rhesus monkeys were treated with a gonadotropin-releasing hormone receptor antagonist to inhibit endogenous FSH and luteinizing hormone (LH) secretion. The gonadotrophin drive to the testis was replaced with a pulsatile recombinant human FSH and LH infusion to maintain testicular volume and circulating testosterone and inhibin B at physiological levels. A selective monotropic elevation of FSH or LH that doubled the concentrations of inhibin B or testosterone, respectively, was then imposed for 4 weeks, each in a group of four monkeys. In a third group (n = 4), the gonadotrophin drive remained clamped at physiological levels. Bromo-deoxyuridine was administered 3 h prior to castration, and the effects of the monotropic hormone increments on germ cell number, S-phase labeling and degeneration were determined. RESULTS: Increased FSH, but not LH, produced increases in testicular volume (P < 0.05), the proportion of A pale spermatogonia entering the cell cycle and the numbers of differentiated spermatogonia and more advanced germ cells (P < 0.05). Indexes for spermatogonia labeling and germ cell degeneration were not affected. CONCLUSIONS: Under physiological conditions, circulating concentrations of FSH directly dictate sperm output of the primate testis by regulating the proportion of Ap spermatogonia in the growth fraction. An effect of FSH on survival of the first generation of differentiated B spermatogonia is not excluded.

Opini Anda

Klik untuk menuliskan opini Anda tentang koleksi ini!

Kembali