[Luteinizing hormone content in the hypothalamus in relation to the physiological status of rats]

Content and relative concentration (per 1 mg of protein) of luteinizing hormone (LH) varied in rat hypothalamus depending on the animal sex and age. In hamster hypothalamuses the hormone content correlated with the state of sexual cycle; maximal content of LH was found during estrus. Content of LH in hypothalamus depend also on the effect of light (rhythmic illumination, permanent light or darkness, duration of the light effect). After gonadectomy content of LH was increased in hypothalamus of female rats within 60 days. Simultaneous hypophys- and ovariectomies increased the LH content in hypothalamus already within 14 days after the treatment. Whole-body perfusion of rats did not alter the LH content in hypothalamus. LH was found in the middle and posterior parts of hypothalamus, particularly, in arcuate nucleus, middle eminence and mammillary bodies.