Changes in the concentration of some minor constituents of milk from cows fed low- or high-fat diets

• 1.1. The concentration of isocitrate and 2-oxoglutarate in cows' milk was determined in cows fed low- or high-fat diets.
• 2.2. The concentration of 2-oxoglutarate in milk correlated positively with the short and medium chain fatty acids in milk fat.
• 3.3. The concentration of isocitrate in milk correlated negatively with the short and medium chain fatty acids in milk fat.
• 4.4. It is proposed that changes in the concentrations of these minor constituents of milk occur as a result of changes in their intracellular concentrations. In the present experiment these changes are probably the result of changes in the rate of fatty acid synthesis de novo in the mammary gland.

     

Effects of milk fat,unhydrogenated and partially hydrogenated vegetable oils on serum lipoproteins in growing pigs

• 1.1. Crossbred Yorkshire (Yorkshire × Landrace) pigs were fed butter oil, cream, low erucic acid rapeseed oil, sunflower oil and partially hydrogenated sunflower oil in amounts representing 30% of energy for periods of up to 13 weeks.
• 2.2. After 13 wk of feeding serum total cholesterol levels of pigs fed milk fat were significantly higher than of pigs fed vegetable oils.
• 3.3. The difference in cholesterol was mainly due to an increase in the density range of 1.063–1.125 g/ml containing pig LDL₂ and some HDL.
• 4.4. A shift towards smaller LDL particle size was apparent in pigs fed milk fat.
• 5.5. The effects of dietary trans fatty acids did not differ from cis polyunsaturated or monounsaturated fatty acids.

     

Blue-Green color and composition of stejneger's beaked whale (Mesoplodon stejnegeri) milk

• 1.1. Two hundred ml of milk were obtained from a lactating Stejneger's beaked whale stranded at Ninilchik, Alaska on 21 Oct, 1980.
• 2.2. Total solids (41%) were similar to values reported for sperm and belukha whales, while fat (17%) was half as great and crude protein (17%) was 2–4 times greater than in milk of these species. Lactose was not detected.
• 3.3. Calcium (0.22%) was greater than reported for pigmy sperm whales but less than for blue whales. Phosphorus (0.07%) was less than for any of the above species. Sodium and potassium concentrations were 0.13% and 0.11%, respectively.
• 4.4. Values (μg/g) for other elements analyzed (magnesium, 42; iron, 35; copper, 2.6; zinc, 1.5; manganese, 0.3; selenium, 0.36) have not been reported for whale milk.
• 5.5. Based on SDS-gel electropherograms, this whale milk did not contain a whey protein corresponding to cattle milk α-lactalbumin.
• 6.6. A blue-green pigment in the milk was identified as biliverdin.

     

Fermentation and the production of volatile fatty acids in the alimentary tract of the rock hyrax,Procavia capensis

• 1.1. Aspects of ruminant-like metabolism were examined in the hyrax Procavia capensis.
• 2.2. High concentrations of volatile fatty acids occurred in the cardiac stomach with a predominance of acetic and lactic acids.
• 3.3. Acetic (69%), propionic (22%) and butyric (8%) acids occurred in highest concentrations in the proximal caecum, with appreciable amounts in the proximal colon, distal caecum and appendices.
• 4.4. The depot fat contained high proportions of unsaturated C₁₈ (linoleic and linolenic) acids.
• 5.5. The glucose level in the plasma was within the range established for non-ruminant herbivores.
• 6.6. The possibility of silage-like fermentation occurring in the cardiac stomach is discussed.

     

Association of cytosolic lipids with fatty acid synthase from lactating mammary gland

• 1.1. Membrane-free cytosol contained over 4% of both the total lipids and phospholipids present in homogenates of lactating rat mammary gland, and much of this lipid was associated with a high molecular weight complex isolated from cytosol by gel exclusion chromatography or by density gradient centrifugation.
• 2.2. This complex principally consisted of polypeptides with apparent molecular weights of 220 and 116kDa. Lipids associated with this complex were transferred to endoplasmic reticulum and to intracellular lipid droplet precursors of milk lipid globules upon incubation in a cell-free system.
• 3.3. This lipoprotein complex was abundant in cytosol from lactating mammary gland, but was diminished in amount in cytosol from involuted mammary glands. The 220 kDa constituent of this complex was identified as the monomer of fatty acid synthase.
• 4.4. These results suggest that fatty acid synthase complex in lactating mammary gland may function in transfer of lipids necessary for formation or growth of lipid droplet precursors of milk lipid globules.

     

Breast,hips, and buttocks revisited: Honest fatness for honest fitness

This paper comments on: Low, B. S., Alexander, R. D., and Noonan, K.M. Human hips, breast, and buttocks: Is fat deceptive? Ethology and Sociobiology 8: 249-247, 1987. In it I argue that:

• 1.1. Sexual selection has probably not been the most important selection pressure on
• 2.female human body shape.
• 3.2. Male humans in different cultures find different aspects of the female body attractive
• 4.and therefore are unlikely to have exerted consistent directional sexual selection on
• 5.the female body.
• 6.3. Breast size is not correlated with lactation success.
• 7.4. Visible hip width is not correlated with parturition success.
• 8.5. Women would lower their fitness if they tried to deceive men about their internal
• 9.pelvic dimensions.
• 10.6. There are many alternative hypothesis to explain the existence of fat onwomen's
• 11.breast, hips, and buttocks.

     

Changes in composition and proteolytic enzyme activities of artemia during early development

• 1.1. The proximate composition, total and free amino acids, and proteases of Artemia nauplii were determined during early development.
• 2.2. Moisture increased from 71.0% to 80.8%, crude protein decreased from 13.2% to 8.8%, crude fat and ash varied slightly.
• 3.3. The total amino acids decreased. Free amino acids changed in three patterns.
• 4.4. Trypsin, chymotrypsin, carboxypeptidase A, B and cathepsin B and C increased in activity. The activity of trypsin was lower, while cathepsin B and C were the highest.
• 5.5. The protease activities were maximal at pH 7.5 and 8.0, and at 45°C on casein.
• 6.6. The optimal pH for carboxypeptidase A was 4.0, for carboxypeptidase B was 4.5, for trypsin and chymotrypsin were 7.0–7.5. The protease(s) active at pH 9.0–9.5 were to be determined.

     

Proteose-peptone fractions of human and bovine milk

• 1.1. Human milk proteose-peptone fraction contained an average of 45% carbohydrate compared to about 11% carbohydrate present in the bovine milk fraction.
• 2.2. The human milk proteose-peptone fraction contained Lactobacillus bifidus var. Penn. growthpromoting factors, whereas there was very little such growth-promoting activity in the bovine milk material.
• 3.3. Polyacrylamide gel electrophoresis showed that human milk proteose-peptone fraction contained 4 major protein components with the respective mol. wts of approx 100,000, 70,000, 30,000, and 13,000. The latter was the most abundant component of human milk proteose-peptone fraction. There was, in addition a very low mol. wt carbohydrate-containing component. Bovine milk proteose-peptone fraction had 3 major protein components with mol. wts of 30,000, 18,000 and 12,000.
• 4.4. The human milk proteose-peptone component with the mol. wt of 13,000 was identified as α-lactalbumin, the component with the mol. wt of 30,000 was identified as a temperature-sensitive protein probably similar to galactothermin, and the components having mol. wts of 100,000 and 70,000 were closely associated to give a protein of a very high mol. wt. This complex also contained carbohydrate and was thus glycoprotein in nature.
• 5.5. The low-mol. wt carbohydrate-containing material was identified as being similar if not identical to glycoprotein B previously described.

     

Influence of dietary sources of fat on lipid synthesis in mink (Mustela vison) mammary tissue

• 1.1. The fatty acid composition of the triglyceride fraction of mink milk sampled during mid-lactation (day 28 post partum) from two nursing mink was compared to that of plasma samples and to the fatty acid composition of the feed rations used.
• 2.2. Chemical analysis of the triglyceride composition of mink milk demonstrated only minute concentrations of fatty acids with a chain length below C₁₄.
• 3.3. The saturated C_16:0- and C_18:0-unit fatty acids in mink milk made up for 24–40% of the total amount of fatty acids extracted, the remainder being represented by mono and polyunsaturated long-chain (C₁₆-C₂₄) fatty acids.
• 4.4. Preliminary in vitro experiments proved the incorporation of¹⁴C-labelled glucose, acetate or palmitate into triacylglycerols in cultures of mink mammary tissue to be linear for at least 2 hr.
• 5.5. The in vitro capacity for de novo fatty acid synthesis in mink mammary tissue using 14C-labelled glucose or acetate was low, i.e. ranging from 0.096–0.109 nmol/g (fresh tissue)/min, and amounted to only about 5% of that obtained in the case of [¹⁴C]palmitic acid incubation.
• 6.6. Following ¹⁴C-labeIled acetic or palmitic acid incubation of mink mammary tissue neither desaturation nor chain elongation was observed.
• 7.7. In response to long-term feeding on rations with two different sources of animal fat (F = fish oil or L = lard) the influence of compositional changes in dietary neutral lipids on the fatty acid composition of the lipids of mink milk is discussed.

     

Uptake of haemolymph glycoprotein by the fat body of Calpodes ethlius (lepidoptera). Evidence that the mechanism does not involve desialylation

• 1.1. Haemolymph and fat body of Calpodes ethlius larvae were examined for the presence of sialic acid.
• 2.2. Haemolymph contained low molecular weight substances that absorbed maximally at 549 nm after reaction with periodic acid and thiobarbituric acid (Warren assay).
• 3.3. Ion exchange chromatography of haemolymph ultrafiltrate gave two chromogenic fractions. The principal chromogen failed to give a direct Ehrlich or resorcinol test for sialic acid.
• 4.4. The thin layer chromatographic mobilities of the chromogens differed from those of N-acetylneuraminic acid.
• 5.5. No sialic acid was released by enzymatic or acid hydrolysis of haemolymph or fat body proteins.

     

The transfer of thyroxine from the mother to the young of the marsupials,the bandicoot (Isoodon macrourus) and the possum (Trichosurus vulpecula)

• 1.1. The young of the bandicoot and possum are of similar weight at birth (200–250 mg) but by day 50 post-partum have weights of 100 and 20 g, respectively. The aim of this study was to determine whether the disparate growth rate was associated with a difference in the transfer of thyroxine from mother to young.
• 2.2. Radioactive thyroxine was injected intramuscularly into the lactating female and 24 hr later a blood sample was obtained from the mother and the pouch young removed. The amount of radioactive thyroxine remaining in the blood and within the young was determined.
• 3.3. The data obtained indicated that milk is a source of thyroid hormones in early pouch life.
• 4.4. The hypothesis that greater quantities of thyroxine are transferred in the milk of bandicoots than that of brushtail possums is not supported.

     

Lipids in the storage organs of three mermithid nematodes and in the hemolymph of their hosts

• 1.1. Trophosomes of the mosquito parasitic mermithid Romanomermis culicivorax and two strains of the blackfly parasitic mermithid Neomesomermis flumenalis contained in order of prevalence: triacylglycerols, phospholipids, sterols and sterol esters.
• 2.2. Triacylglycerols in the trophosomes comprised a wide array of fatty acids, sterol esters a smaller variety.
• 3.3. The degree of unsaturation of triacylglycerols and sterol esters was greater for N. flumenalis than R. culicivorax.
• 4.4. The hemolymph of the three host species (Aedes aegypti, Prosimulium mixtum/fuscum, Simlium venustum) contained an assortment of fatty acids, with a higher degree of unsaturation in the simuliids than in the culicid.
• 5.5. The overall lipid concentration of the blood of A. aegypti was unaltered by parasitism, but the mermithid caused an increase in the myristic acid:palmitic acid ratio in the free fatty acid fraction of the host's haemolymph.

     

A survey of the non-esterified fatty acids and binding proteins in the plasmas of selected animals

• 1.1. The levels of non-esterified fatty acids (NEFA) in the plasma of a variety of animals have been estimated.
• 2.2. Only one of seven elasmobranchs contained detectable levels of NEFA.
• 3.3. The two crustaceans examined contained very low levels.
• 4.4. All the other animals contained circulating levels of a variety of NEFA ranging from 14 to 24 carbon atoms.
• 5.5. The elasmobranchs are unique in that they also do not possess proteins in the serum which bind fatty acids.

     

Hemorrhagic and mojave toxins in the venoms of the offspring of two mojave rattlesnakes (Crotalus scutulatus scutulatus)

• 1.1. The venoms of two Mojave rattlesnakes and those of their offsprings were analyzed for Mojave toxin and hemorrhagic toxin.
• 2.2. The venom of one female, collected in Pima County, Arizona, and the venoms of her six offspring contained hemorrhagic toxin but not Mojave toxin (venom B).
• 3.3. The venom of the second female, captured in El Paso County, Texas, contained both toxins (A + B venom). Of her 10 offspring, five contained venom with both toxins, two had hemorrhagic toxin only, and three contained neither toxin.
• 4.4. Venoms that caused hemorrhage also inactivated complement. A pool of the venoms of the venom B offspring was less toxic than adult pooled venom A.

     

Seasonal changes of total lipids in the turtle Sternotherus odoratus

• 1.1. Seasonal variation in total lipids was examined in several body components of the turtle Sternotherus odoratus.
• 2.2. Carcass fat stores in both sexes were depleted during winter. Additionally, a decline in carcass lipids was associated with increases in gonadal mass.
• 3.3. Concentrations of liver lipids were maximal during August and minimal during winter.
• 4.4. Males showed little seasonal change in plasma lipid levels, whereas females had seasonal peaks temporally associated with ovarian development and carcass fat storage.
• 5.5. Ovarian concentrations of lipids were minimal after nesting and increased during fall.
• 6.6. Results suggest that S. odoratus uses stored fats both for reproduction and maintenance during winter.

     

Comparison of minerals in milk of four species

• 1.1. Milk samples of 4 ml or more were obtained from guinea pigs (Cavia porcellus), dairy cattle (Bos taurus), horses (Equus caballus) and humans (Homo sapiens). The milks were analysed for minerals including calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K) and sodium (Na) by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES).
• 2.2. Calcium was approximately twice as concentrated in guinea pig milk as in cows' milk, which was twice as much as the level in mares' milk, and this, in turn, was twice as concentrated as human milk.
• 3.3. The ratio of Ca to P in guinea pig milk was 1.66:1, while it was 1.24:1 in cows' milk, 1.56:1 in mares' milk and 2.07:1 in human milk.
• 4.4. Potassium was the most abundant mineral in the milks of cows, mares and humans, but not in guinea pig milk, and was much higher in cows' milk than in others.
• 5.5. Sodium was highest in guinea pig milk with cows' milk being a close second.
• 6.6. Magnesium was one-tenth as concentrated as Ca.

     

Histochemical staining of cadmium taken up by the midge larva,Chironomus yoshimatsui (diptera,chironomidae)

• 1.1. The midge larva (Chironomus yoshimatsui) exposed to cadmium (10 μg Cd/ml) for 2 days was histochemically stained with benzothiazolylazo-β-naphthol.
• 2.2. A large portion of cadmium taken up by the larvae was distributed to the digestive tract, epithelial tract and fat bodies.
• 3.3. Cadmium accumulated in the fat bodies was discharged slowly relative to cadmium in the tract contents when the larvae were placed in control water.
• 4.4. Glycogen in the fat bodies of cadmium-exposed larvae was insensitive to PAS staining.

     

Comparative study of the endemic freshwater fauna of lake baikal—I. Phospholipid and fatty acid composition of two mollusc species,Baicalia oviformus and Benedictia baicalensis

• 1.1. Lipid and phospholipid compositions of endemic freshwater molluscs belonging to the class Gastropoda, Baicalia oviformus and Benedictia baicalensis, were studied.
• 2.2. The fatty acids composition of total lipids, neutral, glyco- and phospholipid fraction was investigated by capillary gas chromatography-mass spectrometry.
• 3.3. Ninety-five fatty acids were identified: 23 saturated (both iso- and anteiso-), 28 monoenoic, 14 dienoic and 30 polyenoic.
• 4.4. High percentage of the two main acids, 18:4 and 18:4(n-3) in phospholipid and glycolipid fractions were identified.
• 5.5. A number of unusual polyunsaturated fatty acids, such as 19:4, 18:5(n-3), 24:4(n-6), 24:5(n-6), 24:6(n-3), and furanoid acids, were found.

     

Modulation of mitochondrial ATPase sensitivity to inhibitors and stimulators by diet-induced changes in membrane lipid

• 1.1. Weanling rats were fed diets differing in fatty acid composition to determine if changes induced in cardiac mitochondrial membrane structural components alter the sensitivity of mitochondrial ATPase to inhibition by oligomycin and stimulation by 2,4-dinitrophenol.
• 2.2. Mitochondrial ATPase assayed in situ within the mitochondrial membrane isolated from animals fed diets higher in fatty acids of longer chain length, exhibited greater oligomycin sensitivity and lower 2,4-dinitrophenol-induced stimulation.
• 3.3. Concomitant diet-induced changes occur in the fatty acid, composition of phosphatidylcholine, phosphatidylethanolamine and cardiolipin, increasing overall length of fatty-acyl tails in the membrane phospholipids.
• 4.4. Diet fat mediated alterations in oligomycin sensitivity of mitochondrial ATPase and membrane fatty acid chain length suggest that _vivo changes in thickness of the lipid bilayer may alter mitochindrial ATPase functions.
• 5.5. The present study extends the concept that dietary fat affects mitochondrial membrane structure and function by demonstrating that the membrane-dependent sensitivity of mitochondrial ATPase to inhibitors and stimulators may be modulated by dietary fat.

     

Lipid digestion in cod (gadus morhua)

• 1.1. Cod, 2.6–3.4 kg. were fed a mixed diet of sprat, capelin oil and wheat flour.
• 2.2. Lipids from the feed, stomach and four intestinal segments were separated into tri-, di- and monoglycerides and free fatty acids and analysed by GLC.
• 3.3. All lipolytic products were concentrated in 14:0, 16:0 and 18:0, up to 60% and extremely low in the ω-3 fatty acids.
• 4.4. Residual triglycerides contained 80% of saturated and monoenoic fatty acids.
• 5.5. Linoleic acid increased from 2% in feed TG to 10% in TG of the rectum.