Structural and functional evidence supporting a role for leptin in central neural pathways influencing blood pressure in rats.
Leptin, a peptide hormone normally associated with body weight homeostasis, is implicated in the generation of obesity-induced hypertension. Administration of leptin increases sympathetic nerve activity and blood pressure; however, the neural circuity involved in this pressor effect is not clearly defined. In this review we describe experiments in which pseudorabies virus was injected into the heart, kidney and the vasculature within skeletal muscle to reveal the distribution of neurones in the hypothalamus that project to these cardiovascular tissues. This distribution is compared to the well-documented distribution of leptin receptors. Finally we discuss microinjection studies designed to examine the effect of leptin, in these regions, on sympathetic nerve discharge and arterial blood pressure. Leptin injected directly into the ventromedial hypothalamus, arcuate nucleus and lateral hypothalamic area (particularly the perifornical area) increased lumbar sympathetic nerve activity. In addition, microinjection into the ventromedial hypothalamus and parvocellular paraventricular nucleus increased blood pressure. Our results demonstrate a discrete set of hypothalamic pathways that may underlie the involvement of leptin in obesity-induced hypertension.
Montanaro
Marisa S
MS
Howard Florey Institute and Department of Physiology, University of Melbourne, Victoria 3010, Australia.
Allen
Andrew M
AM
Oldfield
Brian J
BJ
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004525:Efferent Pathways / Q000187:drug effects; D011558:Herpesvirus 1, Suid / Q000502:physiology; D006801:Humans; D007031:Hypothalamus / Q000737:chemistry / Q000187:drug effects / Q000821:virology; D020738:Leptin / Q000502:physiology*; D008297:Male; D051381:Rats; D011956:Receptors, Cell Surface / Q000032:analysis; D054411:Receptors, Leptin; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology
C515448:LEPR protein, human; D020738:Leptin; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin