Jo H. Calkins

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Interstitial tissue of the testis consists of Leydig cells, macrophages, lymphocytes, plasma cells, mast cells and fibroblasts. Previously we have reported that interleukin-1 (IL-1) inhibits Leydig cell androgen production. In the present study, the effect of IL-2 was investigated. Leydig cells (10(5) cells/ml) from adult Sprague-Dawley rats were cultured(More)
The effects of hCG, 8-bromo-cAMP, 4 beta-phorbol 12 beta-myristate 13 alpha-acetate, and forskolin on insulin-like growth factor-I (IGF-I) receptor gene expression of Leydig cells were studied. The treatment of purified Leydig cells with hCG caused a dose-dependent increase in [125I]IGF-I binding to Leydig cells without changes in binding affinity,(More)
Tissue available (bioavailable) testosterone (T) includes circulating free T (FT) and albumin-bound T. A reasonable assessment of bioavailable T can be made by using 50% ammonium sulfate to precipitate sex hormone-binding globulin (SHBG)-bound T. The supernatant non-SHBG-bound T (non-SHBG-T) correlates well with physiological androgen activity. To assess(More)
Human recombinant tumor necrosis factor-alpha (rTNF alpha) alone (up to 1000 units/ml) did not alter either basal or human chorionic gonadotropin (hCG)-induced testosterone formation in primary culture of rat Leydig cells. However, concomitant addition of rTNF alpha with human recombinant interleukin-1 beta (rIL-1 beta) enhanced the inhibitory effects of(More)
Inflammation and infection induce an acute phase response. The response is characterized by fever and production of interleukin-1 (IL-1). In the present study we evaluated the effects of interleukin-1 on Leydig cell function in primary culture. hCG-stimulated testosterone formation was markedly reduced by IL-1, with an ED50 of 1 U/ml. Basal testosterone(More)
We have reported previously that insulin-like growth factor-I (IGF-I) messenger RNA (mRNA) is expressed in Leydig cells and that IGF-I can enhance androgen production, whereas interleukin-1 (IL-1) is a potent inhibitor of Leydig cell steroidogenesis. Molecular cloning studies have confirmed the existence of at least two species of IL-1: IL-1 alpha and IL-1(More)
Interleukin-1 (IL-1) is a potent inhibitor of Leydig cell function. We have reported that IL-1 inhibited hCG-induced cAMP and testosterone formation. In the present study we evaluated the effect of IL-1 on Leydig cell cholesterol side-chain cleavage cytochrome P450 (P450scc) mRNA levels. P450scc is the rate-limiting enzyme for Leydig cell steroidogenesis.(More)
Previously we have reported that human chorionic gonadotropin(hCG)-stimulated testosterone biosynthesis was markedly inhibited by purified natural human interleukin-1 (IL-1). In the present study we evaluated the effects of human and murine recombinant IL-1 (rIL-1) on Leydig cell steroidogenesis in primary culture. Human rIL-1 beta caused a dose-dependent(More)
In the present study, we evaluated insulin-like growth factor-I (IGF-I) messenger RNA expression in the rat testis. Crude interstitial cells were separated into three distinct bands on 15-60% Percoll density gradients. IGF-I mRNA was mainly localized in the Leydig cell-enriched fraction (band 3), while band 1 and band 2 cells did not contain significant(More)
Previously, we have reported that interleukin-1 (IL-1) can modulate Leydig cell steroidogenesis. Recently, IL-1-like material has been shown to be present in the testis; however, the cellular source of this material remains unclear. In the present study we found that human recombinant IL-1 beta (1-100 ng/ml) caused dose-dependent increases in IL-1 alpha(More)