Role of leptin in hypothalamic–pituitary function

• DOI: 10.1073/pnas.94.3.1023
• Publication Date: 2002-07-26T14:31:39Z
• Authors: W. H. Yu; M. Kimura; A. Walczewska; S. Karanth; S. M. McCann
• Keywords: Median eminence; Gonadotropin

A defect in the structure of obese gene is responsible for development obesity ob / mouse. The product expression protein hormone leptin. Leptin causes weight loss and normal mice, it secreted by adipocytes, an important controller size fat stores inhibiting appetite. mouse infertile has a pattern gonadotropin secretion similar to that prepubertal animals. Consequently, we hypothesized leptin might play role control initiated studies on its possible acute effects hypothalamic–pituitary function. After preincubation period, hemi-anterior pituitaries adult male rats were incubated with 3 hr. produced dose-related increase follicle-stimulating (FSH) luteinizing (LH) release, which reached peaks 10 −9 −11 M leptin, respectively. Gonadotropin release decreased at higher concentrations values indistinguishable from pituitaries. On other hand, prolactin was greatly increased manner but only (10 −7 –10 −5 M). Incubation median eminence–arcuate nuclear explants same animals significant increases LH-releasing (LHRH) lowest tested −12 −10 As concentration increased, LHRH significantly less than highest −6 To determine if can also gonadotropins vivo , ovariectomized females bearing implanted third ventricle cannulae injected μg estradiol benzoate s.c., followed 72 hr later microinjection into (0.6 nmol 5 μl) or equal volume diluent. There highly plasma LH, peaked 10–50 min after injection had no effect FSH concentrations, diluent either LH. Thus, very low stimulated hypothalamic LH anterior vitro released not FSH, . results indicate plays controlling stimulatory pituitary actions.