Differential Effects of Leptin on the Invasive Potential of Androgen-Dependent and -Independent Prostate Carcinoma Cells

Obesity has been linked with an increased risk of prostate cancer. The formation of toxic free oxygen radicals has been implicated in obesity mediated disease processes. Leptin is one of the major cytokines produced by adipocytes and controls body weight homeostasis through food intake and energy expenditure. The rationale of the study was to determine the impact of leptin on the metastatic potential of androgen-sensitive (LNCaP) cells as well as androgen-insensitive (PC-3 and DU-145) cells. At a concentration of 200 nm, LNCaP cells showed a significant increase (20% above control; P < .0001) in cellular proliferation without any effect on androgen-insensitive cells. Furthermore, exposure to leptin caused a significant (P < .01 to P < .0001) dose-dependent decrease in migration and invasion of PC3 and Du-145 prostate carcinoma cell lines. At the molecular level, exposure of androgen-independent prostate cancer cells to leptin stimulates the phosphorylation of MAPK at early time point as well as the transcription factor STAT3, suggesting the activation of the intracellular signaling cascade upon leptin binding to its cognate receptor. Taken together, these results suggest that leptin mediates the invasive potential of prostate carcinoma cells, and that this effect is dependent on their androgen sensitivity

Gonadotropin inhibitory substances

A FSH inhibitor from the urine of bonnet monkeys has been isolated and some of its physicochemical, biological, and immunochemical properties have been described. One of the likely sources of the inhibitor in the monkey seems to be the kidney. This inhibitor has been used in delineating the role of FSH in follicular development in the ovary of the female rat. A method has been described for isolating human LH inhibitor in a fairly pure state

The role of fsh and lh in the initiation of ovulation in rats and hamsters: a study using rabbit antisera to ovine fsh and lh

The relative rôles of FSH and LH in ovulation induction in immature and adult cycling rats and hamsters have been evaluated. Both heterologous purified pituitary hormones and homologous crude pituitary extracts have been used as ovulatory stimuli in immature animals primed with PMSG. Well-characterized FSH and LH antisera have been used in the above model systems to achieve specific neutralization of FSH and LH. The present study revealed that LH is the physiological trigger needed for induction of ovulation in both rats and hamsters and FSH cannot, by itself, induce ovulation in the total absence of LH

In vivo evidence of hepato- and reno-protective effect of garlic oil against sodium nitrite-induced oxidative stress

<p>Sodium nitrite (NaNO₂), a food color fixative and preservative, contributes to carcinogenesis. We investigated the protective role of garlic oil against NaNO₂-induced abnormalities in metabolic biochemical parameters and oxidative status in male albino rats. NaNO₂ treatment for a period of three months induced a significant increase in serum levels of glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin, urea and creatinine as well as hepatic AST and ALT. However, significant decrease was recorded in liver ALP activity, glycogen content, and renal urea and creatinine levels. In parallel, a significant increase in lipid peroxidation, and a decrease in glutathione content and catalase activity were observed in the liver and the kidney. However, garlic oil supplementation showed a remarkable amelioration of these abnormalities. Our data indicate that garlic is a phytoantioxidant with powerful chemopreventive properties against chemically-induced oxidative stress.</p