Estrous cycles of rats exposed to different doses of melamine (MA) and melamine and cyanuric acid (MC).

<p>Values are expressed as means ± SD, n = 5. *P < 0.05, **P < 0.01: MA group versus control group and MC group versus control group.</p

Absolute and relative ovary and uterus weights of rats exposed to different doses of melamine (MA) and melamine and cyanuric acid (MC).

<p>Values are expressed as means ± SD, n = 5. *P < 0.05, **P < 0.01: MA group versus control group and MC group versus control group.</p

Photomicrographs of ovary sections.

<p>Hematoxylin-eosin staining illustrating the necrosis of granulosa cells (white arrows).</p

Body weights of rats after exposure to different doses of melamine (MA) and melamine and cyanuric acid (MC).

<p>Values are expressed as means ± SD, n = 5. *P < 0.05, **P < 0.01: MA group versus control group and MC group versus control group.</p

mRNA expressions of antioxidant enzymes in the ovaries of rats exposed to melamine (MA) and melamine and cyanuric acid (MC).

<p>Values are expressed as means ± SD, n = 5. *P < 0.05, **P < 0.01: MA group versus control group and MC group versus control group.</p

Percentages of apoptotic cells in ovaries after rats were exposed to different doses of melamine (MA) and melamine and cyanuric acid (MC).

<p>Values are expressed as means ± SD, n = 5. *P < 0.05, **P < 0.01: MA group versus control group and MC group versus control group.</p

Gross pathological and histopathological changes of kidneys.

<p>Hematoxylin-eosin staining illustrating the gold-brown crystals (black arrow), cellular casts (blue arrow) and compensatory expansion (red arrow).</p

mRNA expression levels of genes associated with steroidogenesis in ovaries of rats exposed to melamine (MA) and melamine and cyanuric acid (MC).

<p>Values are expressed as means ± SD, n = 5. *P < 0.05, **P < 0.01: MA group versus control group and MC group versus control group.</p

Apoptotic cells in rat ovaries detected by TUNEL staining after the rats were exposed to different doses of melamine (MA) and melamine and cyanuric acid (MC).

<p>TUNEL-positive cells were found in the granulosa cells (black arrows).</p

Numbers of atretic follicles in ovaries after rats were treated with different doses of melamine (MA) and melamine and cyanuric acid (MC).

<p>Values are expressed as means ± SD, n = 5. *P < 0.05, **P < 0.01: MA group versus control group and MC group versus control group.</p