Effect of essential fatty acid deficiency on membrane fatty acid content and growth hormone stimulation of rat pituitaries during postnatal development.

M C Soares,M L Aléssio,C L Léger,M T Bluet-Pajot,H Clauser,A Enjalbert,C Kordon,D E Wandscheer

doi:10.1016/s0022-2275(20)41147-2

Abstract

Fatty acid composition of anterior pituitary cell membranes of rats deprived of essential fatty acids (EFA) and of rats receiving a standard diet was determined during postnatal development and in adults. Pregnant rats were fed an EFA-deficient diet and the offspring were fed the same diet after weaning. In parallel, effects of the diet on growth and on growth hormone (GH) responsiveness to GHRH stimulation were determined in control animals. Membrane content of arachidonic acid (20:4n-6) and of its elongation product adrenic acid (22:4n-6) increased regularly from day 2 to day 12 after birth. EFA-deficiency resulted on day 2 in increased oleic acid and in substitution of arachidonic and adrenic acids by corresponding elongation-desaturation products of oleic acid: eicosatrienoic (20:3n-9) and docosatrienoic (22:3n-9) acids. At the age of 24 days, n-9 series fatty acid reached the same level as in adult animals. Two-day-old EFA-deficient rats paradoxically exhibited a higher level of 20:4n-6 as compared to control rats. EFA-deficiency also decreased growth rate and GH pituitary responses to GHRH during the prepubertal period. These results suggest that changes in the lipid structure and in pituitary secretion properties elicited by EFA-deficiency depend upon the stage of development.

Highlights

Fatty acid composition of anterior pituitary cell membranes of rats deprived of essential fatty acids (EFA) and of rats receiving a standard diet was determined during postnatal development and in adults
Membrane lipid composition can be modified by dietary lipids in animals [4] as well as in humans [5]
As EFA are exclusively of dietary origin, their shortage induces EFA deficiency. Cells compensate for such deficiency by increasing oleic acid bioconversion through the desaturatiodelongation system [6]

Summary

Introduction

Fatty acid composition of anterior pituitary cell membranes of rats deprived of essential fatty acids (EFA) and of rats receiving a standard diet was determined during postnatal development and in adults. M deficiency decreased growth rate and G H pituitary responses to GHRH during the prepubertal period These results suggest that changes in the lipid structure and in pituitary secretion properties elicited by EFA-deficiency depend upon the stage of development-Soares, M. Effect of essential fatty acid deficiency on membrane fatty acid content and growth hormone stimulation of rat pituitaries during postnatal development. As EFA are exclusively of dietary origin, their shortage induces EFA deficiency Cells compensate for such deficiency by increasing oleic acid bioconversion through the desaturatiodelongation system [6]. O n the other hand, EFA are precursors of eicosanoids, a large family of signaling molecules including prostaglandins, thromboxanes, prostacyclins, and leukotrienes as well as linear oxygenated derivatives of 20-carbon fatty acids [20]

Objectives

Methods

Results

Conclusion