We have investigated the effect of blocking alpha-MSH on the release of LH in rats at pro-oestrus. Continuous infusion of Pro-Leu-Gly-NH2 (PLG; 0.2 microgram/h), from the afternoon of dioestrus-2 until the day of oestrus, inhibited LH at pro-oestrus and the next ovulation on the day of oestrus. Plasma alpha-MSH levels decreased significantly in rats treated with PLG. This inhibitory effect on LH release was not observed in rats treated with a continuous infusion of a diluted antiserum against alpha-MSH (0.5 microliter/h, diluted 1/10) from the afternoon of dioestrus-2 until the day of oestrus. On the contrary, the administration of undiluted antiserum against alpha-MSH (0.5 microliter/h) blocked LH release and ovulation. The release of alpha-MSH into the blood was also significantly blocked by this treatment. When serum levels of progesterone were measured at 12.00 and 14.00 h in rats in which alpha-MSH release was blocked by PLG or concentrated antiserum, a significant decrease was observed when compared with the levels of progesterone in control rats. These results show that the blockade of alpha-MSH inhibits LH release and the next ovulation in rats treated with PLG or with concentrated antiserum against alpha-MSH, through a blockade of progesterone of adrenal origin.

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The objective was to confirm the increased risk of nerve injury in elderly patients, in the lower third molar extraction, by studying radiological signs of relationship and the position of the inferior alveolar nerve.