Effect of alpha-melanotropin hormone on serum levels of luteinizing hormone and progesterone in experimental rat autoimmune oophoritis

We studied the effect of alpha-melanotropin hormone (α-MSH) on experimental autoimmune oophoritis (EAO), an inflammatory process induced in female rats. During proestrus, serum levels of LH and progesterone in rats with EAO were higher than those of control rats. However, administration of α-MSH to these rats decreased the levels of LH. Similarly, in the following diestrus, rats with EAO had high levels of LH but treatment with α-MSH decreased the levels to diestrus 2 control values. Treatment with α-MSH also reduced the LH levels of control rats in diestrus 2 compared to untreated controls. However, α-MSH treatment had no effect on progesterone levels of either control or rats with EAO. Thus, although α-MSH induced notable changes in levels of LH, this decrease was unable to block the illness.