Fatty acids in energy intake

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Hi All,

The below is pdf-available and, since there was not even a Medline abstract

provided, excerpts are below.

Fatty acids affect how much we eat, it seems.

Dowell P, Hu Z, Lane MD.

MONITORING ENERGY BALANCE: Metabolites of Fatty Acid Synthesis as Hypothalamic

Sensors.

Annu Rev Biochem. 2005;74:515-34. No abstract available.

PMID: 15952896

ABSTRACT

Because energy balance is important for survival, a system is required to

monitor

energy status and to make appropriate adjustments in energy intake and energy

expenditure. In higher animals, a centrally located system has evolved to

accomplish

this task. When caloric intake exceeds expenditure, the surplus is channeled

into

energy storage pathways, primarily the synthesis of fatty acids, which are

converted

into fat and stored in adipose tissue. Thus, metabolic flux through the pathway

of

fatty acid synthesis, located in the lipogenic tissues, reflects the " energy

status "

of the animal. The enzymatic machinery of this pathway is also expressed in the

brain, notably the hypothalamus. In the hypothalamus, intermediates in this

pathway

appear to serve as energy sensors that signal higher brain centers to produce

appropriate responses, e.g., altered food intake and energy expenditure.

CONTENTS

INTRODUCTION ....515

ROLE OF THE BRAIN IN REGULATING ENERGY BALANCE ...516

FORMATION/TURNOVER OF MALONYL-COA AND FATTY ACYL-COAS 517

Malonyl-CoA ...519

Fatty Acyl-CoAs .521

HYPOTHALAMIC MALONYL-COA AND THE CONTROL OF

FOOD INTAKE AND ENERGY EXPENDITURE ..523

Effects of Inhibitors and Activators of Fatty Acid Synthesis/Oxidation. ..523

Energy Balance, Hypothalamic AMPK Activity, and [Malonyl-CoA] ...528

Possible Mechanisms: The Malonyl-CoA Hypothesis ...529

INTRODUCTION

Increased metabolic flux through the pathway of fatty acid synthesis in the

hypothalamus increases the level of key metabolites that signal the need to

reduce

food intake. Two metabolites, malonyl coenzyme A (malonyl-CoA) and long-chain

fatty

acyl-CoAs (particularly monounsaturated fatty acyl-CoAs), have emerged as

probable

signaling metabolites in the hypothalamus. The role for malonyl-CoA in

regulating

food intake was first recognized through the discovery that intraperitoneal

(i.p.)

or intracerebroventricular (i.c.v.) administration of inhibitors of fatty acid

synthase (FAS) (1), which cause accumulation of malonyl-CoA in the hypothalamus

(2),

have a profound anorexigenic effect (3, 4). Likewise, i.c.v. administration of

long-chain fatty acids, e.g., oleic acid, reduces food intake (5, 6). This

review

will focus on the evidence implicating these " signaling metabolites " in the

hypothalamic control of food intake and energy expenditure and will suggest

mechanisms by which this control is exerted.

....

Al Pater, PhD; email: old542000@...

____________________________________________________

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