Localization of leptin receptor splice variants in mouse peripheral tissues by immunohistochemistry

The recently discovered leptin hormone is produced by adipocytes and acts on the hypothalamus inducing satiety and an increase in energy expenditure (for review, see Friedman, 1997), as well as on a number of organs involved in reproduction, metabolism and glucose homeostasis (Ahima et al. 1996; Chehab et al. 1996; Levin et al. 1996). These findings suggest that leptin also acts directly on peripheral tissues. Even though several studies have investigated the localization of the various spliced isoforms of the leptin receptor (Lee et al. 1996; Wang et al. 1996) in peripheral tissues (Ghilardi et al. 1996; Fei er al. 1997; Hoggard et al. 1997), the techniques used in most of them do not allow the exploration of their precise cytological localization, which is a precondition to gaining a better understanding of the functional role of the receptor in these tissues. The present immunohistochemical study was thus performed to obtain cytological details of the localization of the receptor splice variants in a number of peripheral tissues of lean and obese mice.