[Anatomopathologic changes in the testis following prolonged treatment with LHRH agonists. Experimental study in rats]. / Cambios anatomopatológicos en el testículo tras un tratamiento prolongado con agonistas LHRH. Estudio experimental en ratas.

Presentation of a study conducted on 20 male Wistar rats treated for 3 months with Leuprolide (LHRH agonist). Analysis of pathophysiological testicular changes resulting from the treatment and extent of recovery at 3 months of therapy discontinuation, relating those changes to testosterone plasma levels in peripheral blood. Serum testosterone fell to 1.17 +/- 0.30 ng/ml in the treated group, shifting to figures overlapping with normal values within 3 months of discontinuing treatment. Such decreased testosterone levels translate into significant testicular histological damage. Three months after interruption of treatment there is nearly complete recovery of such damage, with just around 10% tubules without spermatozoa, with unchanged germinal line. We conclude that the marked suppression in testosterone levels caused by LHRH agonists translates into a significant degeneration of the seminiferous tubule, which appears to be reversible 3 months after treatment discontinuation.

[Role of testosterone in the testicular microcirculatory changes produced in the rat by the administration of high doses of human chorionic gonadotrophin]. / Papel de la testosterona en las variaciones microcirculatorias testiculares producidas en la rata por la administración de altas dosis de gonadotrofina corionica humana.

A study was performed in 20 male Wistar rats weighing 250-300 gm; 10 comprised the control group and the other 10 were treated with 5 mg/day of cyproterone acetate which was given with the meal for 2 months. The rat testicular microcirculation was studied by laser Doppler flowmetry. Similarly, the testicular interstitial fluid volume and plasma testosterone in peripheral blood were determined. Within each of the two groups, 5 were studied without any pharmacologic stimulation and 5 at 4 hours following the administration of 100 IU subcutaneous HCG. The rats treated with cyproterone acetate had very low levels of serum testosterone (1.254 +/- 0.667) versus the control group (3.686 +/- 0.705), the difference being statistically significant (p < 0.05). Following administration of HCG, the microcirculation changes and the interstitial fluid were the same as those of the control group despite the blockade of the androgenic receptors by cyproterone acetate. The increase in testosterone levels therefore does not appear to mediate the testicular microcirculation changes produced by HCG.

[Testicular microcirculation in rats measured with laser-Doppler flowmetry]. / Microcirculación testicular en la rata medida mediante flujometría laser doppler.

Study carried out in 50 male Wistar rats distributed into 5 groups: baseline and at 2, 4, 8 and 24 hours after subcutaneous injection of Human Chorionic Gonadotropin, 100 IU. It was observed that testicular microcirculatory flow shows a rhythmical fluctuating pattern (5-10 fluctuations per minute), which becomes continuous at 4 hours but recovers at 24 hours. At the same time, there is an increased volume of testicular interstitial fluid that peaks at 8 hours, and returns to baseline levels at 24 hours. Serum testosterone values increase with HCG injection, reaching a peak at 4 hours (25.9 mg/ml), to return to nearly baseline levels at 24 hours (5.04 mg/ml). Disappearance of the rhythmical microcirculatory pattern, and the increase of interstitial fluid volume do not appear to be mediated by testosterone, since the raise in hormone levels, occurred after HCG administration, preceded the observed microcirculatory changes.