Effect of hepatoma on host liver,heart and lung lipids as tumor growth progresses

A large group of rats was transplanted with hepatoma 7288CTC and 4 animals were sacrificed at 3-day intervals for four weeks. Lipid class concentrations, fatty acid class compositions, and the distribution ofcis octadecenoate positional isomers in the major lipid classes were determined for heart, liver and lung at each time period. The hearts of host animals decreased in dry weight as hepatoma growth progressed. At day 30, heart weights were less than two-thirds of initial weights. Lipid class concentrations changed in all three tissues: cholesterol and free fatty acids increased in liver; triglycerides and cholesterol decreased and then increased in heart; and cholesterol, triglycerides and PC decreased in lung as tumor growth progressed. Hexadecenoate percentages exhibited a progressive decrease in all the lipid classes of heart and liver. Although total octadecenoate percentages showed only minor changes, oleate concentrations generally increased and vaccenate levels decreased in heart and liver lipids as tumor growth progressed. Palmitoleate, precursor of vaccenate, exhibited decreased concentrations early that resulted in decreased vaccenate levels. Decreased palmitoleate concentrations suggest inhibition of the Δ9 desaturase system, but normal oleate concentrations complicate this interpretation. Most of the changes in the lipids were detectable 3–6 days after transplantation, indicating the hepatoma affects the lipid metabolism of the host animal early and well in advance of nutritional stresses.     

Changes in fatty acid composition of plasma and oviduct lipids during sexual maturation of Japanese quail

The fatty acid (FA) compositions of plasma and oviduct phospholipids (PL) and triglycerides (TG) were studied throughout the natural sexual development of the Japanese quail. In the oviduct, PL concentration increased rapidly during the period of active oviduct cell proliferation and then remained at a constant level during the phase of cellular hypertrophy. Oviduct and plasma TG concentrations were 2- and 10-fold higher, respectively, in fully developed animals than in immature ones. During natural sexual maturation of the quail, the FA compositions of PL and TG were markedly modified both in plasma and in oviduct. These qualitative changes occurred predominantly during the period of intense cellular proliferation of oviduct cells, and also were observed in immature animals injected with physiological doses of estradiol. In oviduct PL, the proportions of 20∶4n−6 and 22∶4n−6 decreased significantly (from 20 to 10% and 3.5 to 0.7%, respectively) whereas those of 18∶2n−6 increased (from 8.5 to 21%). In contrast, the plasma PL proportions of 20∶4n−6, 22∶4n−6 and 18∶2n−6 were decreased significantly and the percentage of 18∶1n−9 doubled, suggesting that the oviduct is able to utilize certain plasma FA to a greater extent than others. Changes in plasma and oviduct lipid composition occurring in the quail during sexual development may be attributed to estradiol, which stimulates hepatic Δ9 desaturase and inhibits the oviduct Δ6 desaturase. The changes in FA composition observed in oviduct phospholipids are discussed in relation to eicosanoid production and cellular proliferation.     

Occurrence of unusual hexadecenoate fatty acids in hepatoma lipids

Cis-hexadecenoates isolated from rat liver and hepatoma 7288CTC lipids were analyzed for positional isomers by ozonolysis and capillary gas liquid chromatography. In addition to the Δ6, Δ7, Δ9 and Δ11 isomers found in both tissues, the hepatoma neutral and polar lipids contained relatively high percentages of Δ12 and Δ14 hexadecenoates that were virtually absent from liver. The occurrence of these unusual fatty acids may result from an error in lipid metabolism in the hepatoma.     

Changes in flax (Linum usitatissimum L.) seed lipids during germination

Flax (Linum usitatissimum L.) seeds were germinated for 8 d under laboratory conditions, and changes in their lipid fraction were studied by various chemical and chromatographic methods. Total lipid content of the seeds was reduced fourfold at the end of the 8-d germination period as compared to ungerminated seeds on a fresh weight basis. The neutral lipids comprised the major fraction of seed lipids, and triacylglycerols predominated over all other lipid components even during the germination period. Both the spectrophotometric and thin-layer chromatography-flame-ionization detection methods of quantification showed a considerable increase in the content of free fatty acids. The glycolipid fraction of lipids increased, but the phospholipid fraction exhibited only minor changes. Lipase activity of flaxseed increased at the beginning of germination and then remained constant until the fifth day. Phosphatidylcholine was the major phospholipid of flaxseed lipids, and its content was reduced during the germination. The contents of lysophosphatidylcholine and phosphatidic acid increased from negligible amounts to 46% of the total phospholipids. Linolenic, linoleic, and oleic acids, respectively, were the predominant fatty acids of all the lipid fractions of flaxseed, and remained unchanged during the germination period. The glycolipid fraction had the lowest content of polyunsaturated fatty acids. Fatty acids C_14:0, C_20:0, C_24:0, C_20:1, C_22:1, and C_20:5 appeared after d 2 of germination in neutral, glyco- and phospholipid fractions.     

Lipid composition of yoshida ascites hepatoma and of livers and blood plasma from host and normal rats

The lipid composition of Yoshida ascites hepatoma cells was analyzed together with that of ascitic plasma and of livers and blood plasma from host and normal rats. In comparison to normal livers, host livers showed no significant differences in the content of the various lipid classes, but contained a higher percentage of palmitic acid and a lower proportion of arachidonic acid in the major phospholipid classes. In addition, tumor growth induced a marked hypertriglyceridemia in host animals; changes in the concentration of other plasma lipid classes were not statistically significant. The ascitic plasma contained small amounts of lipids mainly constituted by cholesteryl esters and phospholipids. Yoshida hepatoma cells contained less phospholipids in comparison to both host and normal liver, while the increased level of triglycerides and the decrease of free fatty acids were not statistically significant. Hepatoma cells showed appreciable amounts of ether-linked lipids associated in part to neutral lipids (as glyceryl ether diesters) and, in part, to ethanolamine and choline phosphoglycerides. The alkyl groups in GEDE as well as in ethanolamine and choline phosphoglycerides were mainly constituted by C_16∶0 and C_18∶0 followed by C_18∶1. The alk-1-enyl groups in ethanolamine and choline phosphoglycerides were C_16∶0 and C_18∶0 with only a minor proportion of C_18∶1. In comparison to both host and normal liver, Yoshida hepatoma cells showed significant changes in the fatty acid composition of neutral lipids and phospholipids. Some of the major changes consisted of an increase of monoenoic acids associated with a decrease of arachidonic and docosahexaenoic acids in phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol.     

Changes of lipids in insect (Rhynchophorus phoenicis) during cooking and storage

Lipid stability of Rhynchophorus phoenicis (RP) larvae extract (edible oil) was evaluated, including the usual analytical indices and analysis by Fourier transform infrared (FTIR) spectroscopy at different periods of freezing, refrigeration storage conditions and cooking methods. A study of the quality of oil obtained showed that boiling before smoking reduced the acidity of the oil. Boiling, refrigeration for 3 days or more, freezing, sun drying, and electrical drying increased the acidity of the oil. Culinary and dehydration methods significantly increased the peroxide value, especially when boiling preceded dehydration. Cool storage had protective effects on lipid oxidation of RP larvae. Smoking methods produced good quality products.     

Diester waxes in surface lipids of animal skin

The literature is surveyed on two types of diester lipid that occur on the skin surfaces of animals: Type 1, a hydroxy fatty acid of which the hydroxyl group and the carboxyl group are esterified respectively with another fatty acid and a fatty alcohol, and Type 2, and alkane α,β-diol of which each OH group is esterified with a fatty acid. New data presented here show that the cow, rabbit and cat produce Type 1, whereas the dog, mouse, guinea pig and baboon produce Type 2 diesters. Each occurs as a major component of the surface lipid. The homologue distribution is given for Type 1 diesters of cow, rabbit and cat as well as the Type 2 diesters of dog and mouse. Distribution of long chain fatty acids of Type 1 diesters parallels that of the fatty alcohols suggesting a biogenetic relation between the two types of compounds. GLC of total diesters for the cow suggests that the components are assembled randomly during biosynthesis. Molecular weight of these diesters are in the range of those of natural triglycerides composed mainly of C₁₆ and C₁₈ fatty acids. Presented at the 60th AOCS Annual Meeting, San Francisco, April 1969, as part of a Symposium on Natural Waxes.     

Changes in plasma lipids,lipoproteins, triglyceride secretion and removal in chicks with estrogen implants

Estradiol implants in chicks resulted in marked elevation of all major plasma lipids with greatest increase in triglyceride (TG) followed by phospholipid (PL) and cholesterol (C). During the two-wk period, plasma TG level in estrogen (E)-treated chicks increased to about 45 times that of controls (139.6 vs 6,368.3 mg/dl). The level of cholesterol also increased steadily during the same period, attaining nearly a six-fold increase in comparison with the control (150.7 vs 871.8 mg/dl), and the level of PL was markedly elevated from 209 to 2,861 mg/dl. Besides the induction of hyperlipidemia, E treatment also resulted in a notable alteration in the fatty acid composition of plasma lipids; there was an increase in oleic acid concomitant with a decrease in polyunsaturated fatty acids, particularly, linoleic acid. One day after implantation, the percentage of oleic acid in TG fraction increased from 39.2 to 43.7%, reaching 55.4% of the total fatty acids at day 14. In contrast, the levels of linoleic and arachidonic acid decreased significantly from 16.1 to 8.3% and 4.3 to 0.6%, respectively, during the same period. In cholesteryl ester (CE) and PL, the oleic acid level also increased from 25.2 to 47.3% in the former and from 11.9 to 29.6% in the latter, reflecting enhanced hepatic lipogenesis. Analysis of plasma lipoproteins in E-treated chicks revealed dramatic alterations in the concentrations of lipids and protein in individual lipoprotein fractions, especially very low density lipoprotein (VLDL) fraction. The respective levels of TG, C and PL in the VLDL fractions were 10.0, 0.6 and 1.0 mg/dl in the control, and 3,904.4, 530.3 and 1,365.2 mg/dl in chicks implanted with estrogen for seven days. The concentrations of TG, C and PL also were markedly increased in the low density lipoprotein (LDL) fraction in these birds. However, the cholesterol content of the high density lipoprotein (HDL) fraction was decreased dramatically in E-treated chicks (47.1) relative to the control (121.5 mg/dl). The protein level in the VLDL fraction from E-treated chicks was profoundly elevated to a level 300-fold greater than controls. TG secretion rates were measured in vivo following the administration of Triton WR-1339. In control chicks, plasma TG secretion rate was 2.29 mg/min; whereas, chicks treated with E for one and three days showed significantly higher TG secretion rates of 3.18 and 5.27 mg/min, respectively. TG removal rates were measured in vivo after administration of a 10% fat emulsion. Although plasma TG concentrations were different between control and E-treated birds, no significant differences were found in TG removal rates in those birds, indicating no impairment of TG clearance in E-treated chicks.     

A comparison of lipids from liver and hepatoma subcellular membranes

Subcellular fractions of nuclei, mitochondria, endoplasmic reticulum, plasma membrane and cytosol were prepared from liver and hepatoma 72288CTC. Marker enzyme activities, biochemical compositions and electron microscopy were used to establish purity. Hepatoma NADH: cytochrome C reductase and 5′-nucleotidase exhibited abnormal subcellular distributions. The lipids from the subcellular fractions were examined in detail. Mitochondria and plasma membranes were characterized by elevated percentages of diphosphatidylglycrerol and sphingomyelin, respectively, in both tissues. All hepatoma subcellular fractions contained dramatically elevated levels of sphingomyelin and cholesterol, two components that form preferential strong complexes in vitro. The fatty acid composition of hepatoma sphingomyelin differed markedlg from liver and, unlike liver, did not exhibit organelle specific compositions. Some hepatoma lipid classes contained reduced percentages of palmitate while others contained higher levels. Hepatoma phosphatidylcholine and phosphatidylethanolamine from organelles contained lower percentages of long chain polyunsaturated fatty acids than liver. Generally, unique fatty acid profiles exhibited by individual phospholipid classes of liver subcellular fractions were absent or much reduced in the hepatoma. The ratios of oleate to vaccenate were near one for most of the phospholipid classes of most liver fractions, but all hepatoma classes, with few exceptions, contained a much higher percentage of oleate in all subcellular fractions. The hypothesis is proposed that the origin of some acyl moieties for the biosynthesis of various hepatome lipid classes differs from liver sources. The possible changes in acyl pools, sources and compartments for complex lipid biosynthesis could result in change in the quantities of molecular species that could contribute to the abnormal properties of the hepatoma membranes.     

Lipid composition of morris hepatoma 5123c,and of livers and blood plasma from host and normal rats

The lipid composition of Morris hepatoma 5123c was analyzed together with that of liver and blood plasma from both normal and tumor-bearing rats. The results showed that the liver of tumor-bearing rats contained higher amounts of glycerides, cholesteryl esters, free fatty acids and phospholipids than the liver of normal rats. In the blood plasma of tumor-bearing rats, there was an increase of free cholesterol and triglycerides; this latter difference, however, was not statistically significant. Acyl chain changes in the liver of tumor-bearing rats consisted of an increase of palmitic and oleic acids and a decrease of stearic and arachidonic acids in phosphatidylinositol. Morris hepatoma 5123c contained a lower amount of triglycerides than the livers (both host and normal) and showed a significant decrease of total phospholipids when compared to the host liver. The major acyl chain changes found in Morris hepatoma 5123c compared with both normal and host rat livers were: a) a higher percentage of arachidonic acid together with a lower proportion of palmitic acid in cholesteryl esters; b) an increase of stearic and arachidonic acids and a decrease of palmitic acid in triglycerides; and c) a higher level of palmitic and oleic acids associated with a lower percentage of stearic and C₂₂ polyunsaturated acids in phosphatidylcholine.     

Effects of lupin oil on carp lipids during chilling 1. Changes in lipid class composition

The effect of lupin (Lupinus termis) oil on the muscle lipids of carp (Cyprinus carpio) during chilling was studied. During chilling, total lipids decreased whereas triglycerides remained almost constant. Neither the behavior of total lipids nor that of triglycerides during chilling was affected by the composition of the dietary lipids. The proportions of ?free”? fatty acids increased and the proportions of phospholipids decreased during chilling. These changes were markedly affected by the composition of the diet.     

Rapid analysis of fatty acids in plasma lipids

A rapid and convenient procedure for the quantitative determination of the fatty acid composition of plasma lipids is described. Human plasma was applied directly to the preadsorbent zones of thin-layer silica gel plates with added antioxidant, internal standards and carriers. The thin-layer chromatography (TLC) plates were partially developed with methanol followed by chloroform/methanol (1∶1, v/v), and then they were fully developed in hexane/diethyl ether/acetic acid (80∶20∶1, v/v/v) to separate the major classes of lipids. Silica gel from regions containing the separated lipids was scraped into screw-capped tubes and treated with boron trifluoride-methanol prior to gas chromatography. The method of direct application to TLC plates gave yields and compositions of fatty acids very similar to the method of applying extracted plasma lipids. This relatively simple method is suitable for analyzing the fatty acids in plasma lipids from a 50 microliter finger-tip blood samples from an individual, and it may be useful in wide-scale screening of different individuals to estimate the relative amounts of ingested polyunsaturated fatty acids. Pfizer Biomedical Research Awardee.     

Liver lipids during development

The fatty acid composition of the major liver microsomal phospholipids has been studied during pre- and postnatal development of the rabbit. The fatty acid composition of the total lipids, phosphatidyl choline, and phosphatidyl ethanolamine from animals −6, −3, 0, +3, +6, +9, +16, and +112 days of age was determined. Fatty acid composition is similar in phosphatidyl choline and phosphatidyl ethanolamine for oleic acid at +3, +6, +9, and +16 day old animals; palmitoleic acid at +9 day old animals and linoleic acid at −6, −3, and 0 day old animals. Palmitoleic acid demonstrated a uniform decrease during early development in the total lipids and in both phosphatidyl choline and phosphatidyl ethanolamine; however, in the 112 day animal, the amount was just slightly lower than that observed for the earliest prenatal animal studied. Oleic acid decreased considerably during early postnatal development in the total lipids, phosphatidyl choline and phosphatidyl ethanolamine, but an increase in the 112 day animal was observed. Linoleic acid fluctuated considerably throughout postnatal development in the total lipids as well as in the two major phosphatides. Lecithin biosynthesis has been studied by two pathways during development of rabbit liver from −6 days to +110 days. The two pathways of lecithin biosynthesis were evaluated by assaying the activities of the liver enzymes choline phosphotransferase and phosphatidylmethyltransferase at different time intervals during development. The greater enzymatic activity was observed in the cholinephosphotransferase during development.     

Changes in the fatty acid composition of rat lung lipids during development and following age-dependent lipid peroxidation

Analyses of the fatty acid content and composition of various lung lipids were conducted in rats 1 day, 5 days, and 12 days after birth and in adult animals in order to define more clearly the specific lipid peroxidizing system found in neonatal rat lungs. Lipid peroxidation occurs in the 900×g supernatant fraction of rat lung homogenates in an age-dependent manner independent of the addition of any factor and is maximal at 5 days of age. No lipid peroxidation is evident in similar preparations of either newborn or adult lung tissue. As the animals develop, arachidonic and docosahexaenoic acids, fatty acids which are both highly susceptible to lipid peroxidation in the presence of a suitable catalyst, decrease gradually when measured as the percentage of the total fatty acids in the triglyceride fraction of the lung. The total quantity of triglycerides, however, is significantly lower in lungs from 1-day-old rats than at any other age. The fatty acid composition and total quantity of both lung phospholipids and lung free fatty acids do not show similar changes. Following in vitro incubation of the 900×g supernatant fraction of peroxidizing lung homogenates, an appreciable decrease in the amount of arachidonic and docosa-hexaenoic acid could be detected in lung triglycerides. Less extensive decreases were observed in the phospholipid fraction. No changes in these components were observed in newborn or adult animals. The addition of triarachidonin to the 900×g supernatant fraction of lung homogenates resulted in increased malondialdehyde release at all ages tested while added arachidonic acid increased the formation of malondialdehyde only in 5- and 12-day-old rat lung preparations. The addition of triolein, cholesterol arachidonate, and diarachidonyl phosphatidylcholine had no effect on malondialdehyde formation at any age. The age-dependent lipid peroxidation observed after in vitro incubation of rat lung homogenate preparations, therefore, may result from the relatively high concentration of triglycerides containing polyunsaturated fatty acids present in the neonatal tissue. As the susceptible polyunsaturated fatty acids of lung triglycerides are replaced by less unsaturated species, this activity may diminish concomitantly. Recipient of Public Heath Service Research Career Development Award 5-K04-HD00068 from the National Institute of Child Health and Human Development.     

Abnormal plasma lipids of patients withRetinitis pigmentosa

Retinitis pigmentosa (RP) is a hereditary retinal degeneration of unknown etiology, resulting in progressive night blindness, loss of peripheral vision, abnormal retinal pigmentation and reduced electroretinographic response. Docosahexaenoic acid (22∶6ω3) is found in high concentration in the rod outer segment membranes of the retina. Previous reports of low 22∶6ω3 in blood lipids or phospholipids in RP patients prompted us to evaluate the complete fatty acid (FA) profiles of plasma phospholipids (PL), cholesteryl esters, triglycerides (TG) and nonesterified fatty acids (NEFA) in ten patients with RP. In the PL fraction, we found significantly depressed levels of 22∶6ω3, 22∶5ω3, total ω3, 22∶5ω6, 22∶4ω6 and total ω6 polyunsaturated FA (PUFA), and elevated total saturated acids. Plasma TG showed normal levels of PUFA, normal total saturated FA and total monounsaturated FA. The NEFA fraction showed significant elevation in total saturated FA with depressed total ω6 PUFA. Evidence is accumulating that RP is associated with abnormal PUFA and lipid metabolism. Based in part on a paper presented at the Third International Congress on Essential Fatty Acids and Eicosanoids, Adelaide, Australia, March 1992.     

Changes in serum lipids in rats treated with oral cooper

Disturbances in lipid metabolism during copper deficiency in rats are well recognized. Copper deficiency is associated with the spontaneous retention of hepatic iron. Previous studies have reported that hypercholesterolemia and hypertriglyceridemia are associated with elevated hepatic iron concentrations in copper deficient rats. There was a direct relationship between the magnitude of blood lipids and the concentration of hepatic iron. Based on these data, it has been hypothesized that iron was responsible for the development of lipemia of copper deficiency. In this study was determined the effect of increasing doses of Cu(10, 20 and 50 ppm) in the diet, on the serum total lipids, total cholesterol, triglycerides (triacylglicerols), phospholipids, non-esterified fatty acids (NEFA) and liver iron and zinc concentrations in normal rats. The results were compared with normal rats that received a balanced diet containing 0.6 and 6 ppm of Cu, respectively. The results show that Cu-supplement diminished the cholesterol and triglyceride serum levels, increased the level of phospholipids, NEFA and concomitantly decreased the hepatic concentrations of Fe and Zn. There was a statistically significant (p < 0.05) simple correlation between triglycerides and liver Fe (r = 0.917; R2 = 64.03%), cholesterol and liver Zn (r = 0.872; R2 = 76.07%), cholesterol and liver Fe (r = 0.995; R2 = 99.10%), liver Fe and liver Cu (r = -0.612), liver Fe and liver Zn (r = 0.837), liver Cu and liver Zn (r = -0.612), and serum triglycerides and liver Zn (r = 0.967). The mechanism(s) by which Fe and Zn determine these changes is not known; none of the enzymes that act in cholesterol and triglyceride metabolism and biosynthesis require Fe and/or Zn. The increase of NEFA is due to changes in the process of lipolysis and re-esterification of the fatty acids in blood. However, additional studies are needed for the precise mechanisms of this interrelationships to be clarified.     

Intake of different eicosapentaenoic acid-containing lipids and fatty acid pattern of plasma lipids in the rats

The ethyl ester of eicosapentaenoic acid (EPA) is the only pure EPA-containing lipid available in bulk for oral administration. However, there is doubt as to whether EPA ethyl ester can efficiently increase the plasma levels of EPA in comparison with the ability of other kinds of EPA-containing lipids to do so. Therefore, two other kinds of EPA-containing lipids were prepared to study the efficiency of oral administration of those lipids for increasing the EPA content in plasma phospholipids and cholesteryl esters. EPA-containing lipids which were investigated were [A], 1,2,3-trieicosapentaenoyl-glycerol, [B] 2-eicosapentaenoyl-phosphatidylcholine and [C] ethyl ester of EPA. An adjusted amount of lipids [A], [B] and [C] was administered to rats through a gastric tube for 4 days (the first experiment) or for 10 days (the second experiment), and the fatty acid composition of plasma phospholipids and cholesteryl esters was determined. In the first experiment, there were no significant differences in the efficiency for increasing EPA levels in either phospholipids or cholesteryl esters among the lipids. In the second experiment, the EPA levels of both plasma phospholipids and cholesteryl esters of rats administered ethyl ester of EPA were significantly higher than those of rats administered 2-eicosapentaenoyl-phosphatidylcholine. The EPA levels of the rats administered 1,2,3-trieicosapentaenoylglycerol were between the levels of the two groups mentioned above, but the differences in the EPA levels were not significant. Although an ethyl ester-type molecule is not a naturally occurring lipid, ethyl ester of EPA is equal to 1,2,3-trieicosapentaenoyl-glycerol and appears to be superior to 2-eicosapentaenoyl-phosphatidylcholine as to the efficiency for increasing EPA levels in total plasma phospholipids and plasma cholesteryl esters.     

Correlation in the proportion of oleic to vaccenic acid of plasma phospholipids with the early stages of hepatoma 7288CTC growth

The major octadecenoate isomers, oleate (Δ9) and vaccenate (Δ11), were measured in the plasma phospholipids of rats bearing hepatoma 7288CTC as the tumor developed. The percentage of vaccenate decreased from 45% of the octadeceoate fraction at day zero to 25% by the 15th day. A significant decrease (45% to 35%) in the percentage of vaccenate occurred by the sixth day, well in advance of detectable tumor growth. The percentage of vaccenate continued to decrease as a function of time until day 15, after which it remained constant. Detection of alterations in plasma phospholipids at an early stage of tumor development in rats suggests that experiments should be carried out to determine if the same effects occur in humans.     

Changes in lipid components of seeds during growth and ripening of cacao fruit

The biosynthesis of lipid in maturing cacao seeds was studied over two cropping seasons (1975\s-1976) in Brazil using hybrids produced by cross pollination of Catongo with Amelonado cultivars. Seeds were collected at intervals between seed solidification (110\s-120 days postpollination) and harvesting of ripe fruits at 175\s-180 days. Lipid accumulated in seeds at a rapid, linear rate after the seeds solidified until near the beginning of ripening, when lipid build up proceeded at a greatly reduced rate. Triglyceride was the major lipid component at all stages of maturity, increasing from 69% to 96% of the total lipid over the period studied. The contributions of other lipid components to total lipids became less prominent as fat accumulated in seeds. However, on an individual seed basis their mass increased throughout development, except for phospholipids and diglycerides, which decreased on a mass/seed basis in the latter stages of fruit maturation. Since the rate of triglyceride production slowed at about the same time, the reduced amounts of phospholipids and diglycerides indicate the classical Kennedy pathway for triglyceride synthesis is operative in seeds of cacao. Fat present early in seed development was more unsaturated than typical cocoa butter of commerce. However, as lipid deposited during the period of active lipid synthesis, starting at about 130 days postpollination, a normal fatty acid composition was quickly established and did not change materially thereafter.