Rats that were starved, and thus had low levels of leptin in their blood serum levels also had lower levels of these two enzymes. Consistent with the lower levels of the enzymes, these fasted rats likewise did not have a significant amount of the active (cleaved form) of thyrotopin-releasing hormone. Giving leptin directly to these rats, increased enzyme levels and, inevitablely, the amount of active thyrotopin-releasing hormone. These data provide evidence for an additional key regulatory point in the control of energy balance through leptin and may suggest novel therapeutic strategies for treatment of obesity and thyroid axis–related diseases.
Author contact:
Eduardo A. Nillni Brown Medical School/Rhode Island Hospital, 55 Claverick St. Providence, RI 02903, USA. Phone: 401-444-5733; Fax: 401-444-6964; E-mail: Eduardo_Nillni@Brown.edu
Journal of Clinical Investigation