Hans Fisher

Environmental Temperature and Composition of Body Fat.

Summary Samples of subcutaneous body fat were analyzed for fatty acids and iodine values in hens maintained at 3 environmental temperatures. It was found that fat from hens maintained at 0°C was significantly more unsaturated and contained more di- and hexa-enoic acid than fat from birds kept at either 21° or 32°C. There were no changes in deep body temperature or temperature of the tissue at site of fat biopsy which correlated with the changes in fat composition. It is suggested that metabolic adjustments associated with cold adaptation are responsible for the changes in body fat composition.

Serotonin in Involuntary Movement Disorders

Several recent studies have emphasized that serotonergic pathways in the CNS are intimately involved in the modulation of motor behavior, and in the pathophysiology of human involuntary movement disorders. These observations are supported by recent reports demonstrating large serotonergic innervation of the striatum and substantia nigra, and a close interaction between the activity of serotonergic neurons with the dopamine system in the striatum and nigra. In the following communication we summarize evidence demonstrating defective serotonergic functions in a number of human movement disorders and discuss their management with serotonergic drugs.

Nitrogen retention in rats fed on diets enriched with arginine and glycine

1. Nitrogen retention was measured in adult rats (250-350 g) subjected to the trauma of hind-leg fracture and given diets with or without arginine plus glycine supplementation. Observations were also recorded on excretion of creatine, creatinine, allantoin, and orotic acid. Liver and skeletal muscle transaminase activities were also determined. 2. When traumatized rats weighing approximately 250 g were given a diet with 200 g casein/kg, supplemented with 20 g arginine and 10 g glycine/kg (EC diet) or a casein diet made isonitrogenous with the EC diet by addition of aspartic acid (C diet), a 60-70% increase in N retention was observed for the first 5 d post-injury for animals consuming the EC diet. A soya-bean (S) diet, isonitrogenous to the diet containing 20% casein, supplemented with arginine and glycine was as effective as the EC diet in promoting significantly better N retention of traumatized rats (350 g) in comparison to rats given the C diet. 3. When the dietary casein content was reduced to 100 g/kg, supplements of 10 g arginine and 5 g glycine or 20 g arginine and 10 g glycine/kg did not improve N retention. It is suggested that both protein quality and protein quantity are important following injury. 4. An increased excretion of creatine was observed in traumatized rats given the high-protein diets supplemented with arginine and glycine. No consistent changes were noted for urine creatinine. 5. 5. Urine allantoin levels remained stable after leg-fracture in rats consuming either the C or EC diets. Differences in the levels of urine orotic acid were found during both the pre- and post-injury periods in rats given the C, EC or S diets. 6. The mechanisms responsible for the improved N retention of traumatized rats consuming the high-protein diets with supplements of arginine and glycine may be related to the role of arginine both as a constituent of muscle tissue and as an intermediate in the urea cycle. 7. In traumatized rats fed the C or EC diets, liver transaminase activity increased whereas the transaminase activity in skeletal muscle decreased. These results support the recent concept that the increased excretion of N following injury arises from diminished reutilization of amino acids by muscle tissue without an acute increase in the rate of muscle catabolism.

Dietary saponin and plasma cholesterol in the chicken.

Summary A study with growing chicks and adult roosters indicated that dietary saponin will depress blood plasma cholesterol previously elevated by feeding low protein levels in presence and absence of dietary cholesterol. It is suggested that complexing of saponin with cholesterol secreted in the intestinal lumen makes less cholesterol available for reabsorption from the intestinal tract.

Increased Incidence and Severity of Neuroleptic-Induced Movement Disorder in Pinealectomized Rats

The effects of prior pinealectomy on neuroleptic-induced perioral movements were examined in male Sprague-Dawley rats. Treatment with haloperidol resulted in significantly more severe movement disorder in pinealectomized rats than in unoperated control rats. Subsequent administration of melatonin (4 mg, i.p.) was associated with a nonsignificant reduction of the severity of movements in the pinealectomized rats within one hour. We conclude that pinealectomy facilitates the onset of neuroleptic-induced perioral movements, and suggest that impaired melatonin secretion may be implicated in the pathophysiology of tardive dyskinesia in humans.

The presence and significance of carnosine in histamine-containing tissues of several mammalian species

Histamine is known to exert profound effects on the cardiovascular system in many mammals. Carnosine (β-alanyl-l-histidine) is a dipeptide previously known to be present only in a few tissues. It is our hypothesis that carnosine serves as a non-mast cell reservoir for histidine, available for histamine synthesis during periods of physiologic stress. To validate this hypothesis, we demonstrated the existence of carnosine in multiple histamine-rich tissues in several mammalian species; documented a metabolic link between carnosine and histidine, histamine and 3-methylhistamine (a degradation product of histamine) in unstressed animals, and showed that tissue carnosine is decreased simultaneously with an increase in tissue histamine during stress.

Cholesterol-Lowering Effects of Certain Grains and of Oat Fractions in the Chick.

Summary The plasma cholesterol-lowering activity of whole ground oats and its components was studied in chicks fed hypercholesterolemic diets. Oat hulls were most effective whereas oat starch and oat oil had no cholesterol-lowering activity. Liver lipids and cholesterol were also significantly reduced by whole oats and oat hulls, and, to a lesser extent, by dehulled oats. In contrast to observations made with pectin or scleroglucan, fecal lipids and sterols were not increased by the feeding of whole oats or oat hulls.

The influence of dietary fat on the incorporation of fatty acids into body and egg fat of the hen

Abstract The influence of dietary fats on the fatty acid composition of body and egg yolk fat was investigated in leghorn hens. The following results were obtained: 1. 1. Body fat was influenced by ingestion of either saturated or unsaturated fatty acids. 2. 2. Egg fat was influenced only by unsaturated fatty acids. 3. ]3. This study suggests that, in cases of dietary insufficiencies of polyenoic acids, the hen selectively draws upon its body depot fat for the production of egg fat. Under normal conditions the polyunsaturated acids not synthesized de novo appear to be transferred directly from the diet.

Ethanol consumption following acute fenfluramine, fluoxetine, and dietary tryptophan

Male Sprague-Dawley rats fed a commercial diet with or without tryptophan supplementation (0.5% L-TRP) were treated with single IP injections of fenfluramine or fluoxetine. Rats had been water deprived prior to injection and food was removed during the period of fluid availability. They were offered, following drug or saline injection, water, a 5% ethanol solution, or an isocaloric sucrose solution (8.75%) for 1 h. Fenfluramine injection significantly reduced intake of all fluids, but its effect on ethanol was significantly greater than for water or sucrose solutions. Fluoxetine suppressed water and ethanol intake but not that of sucrose; the reduction in ethanol intake was significantly greater than for water. Ingestion of the tryptophan-supplemented diet in the absence of any drug treatment had no effect on fluid intake. However, the tryptophan supplementation significantly enhanced the reduction in ethanol intake induced by fenfluramine and fluoxetine. It appears that both fenfluramine and fluoxetine decrease ethanol intake more so than that of water or sucrose and that this effect is exacerbated by tryptophan supplementation.

Existence of carcinine, a histamine-related compound, in mammalian tissues

Carcinine (beta-alanylhistamine) was synthesized in vitro from histamine and beta-alanine. It was detected quantitatively using an HPLC method previously described for the quantification of the related compounds histamine, histidine, carnosine and 3-methylhistamine. Carcinine was identified in several tissue of the rat, guinea pig, mouse and human, and was then shown to be metabolically related in vivo to histamine, histidine, carnosine and 3-methylhistamine through radioisotopic labeling. The results demonstrate that carcinine may be concurrently quantitated using the same HPLC method as that used to measure histamine, histidine, carnosine and 3-methylhistamine. These findings suggest a role for carcinine in the carnosine-histidine-histamine metabolic pathway and in the mammalian physiologic response to stress.