Figure 7: Effect of melatonin on circulatory level of plasma melatonin in PCO rats showing significant decrease in plasma melatonin level. Melatonin treatment maintained its own endogenous plasma level comparable to control groups of rats; Mean ± SE; n=6, Con: Control, L: Letrozole, L+Mel=Letrozole +Melatonin, Mel: Melatonin. Con vs. L=p<0.01; Con vs. L +Mel=p<0.01; Con vs. Mel=p<0.01; L vs. L+Mel=p<0.01.