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Biomedical subjects

C Pignatti

Publications and source records attributed to C Pignatti.

At least 37 records · Page 2Linked to original sources
PubMed1985

Reduced mechanical activity of perfused rat heart following morphine or enkephalin peptides administration.

In the isolated and perfused rat heart, the addition of morphine, methionine-enkephalin or leucine-enkephalin to the coronary perfusate, significantly reduces the mechanical activity by negatively affecting both the heart rate and the developed tension. These effects are dose dependent and maximally evident with leucine-enkephalin. Furthermore all the opioids strongly reduce the activity of isoproterenol-stimulated hearts. The suggestion is made that opioid peptides directly influence the cardiac mechanical activity possibly by interacting with membrane-receptor systems.

Animals↗
PubMed1984

Effect of C 18:3 (n-3) dietary supplementation on the fatty acid composition of the rat brain.

Weanling rats have been fed different diets containing hydrogenated coconut oil or a mixture of grapestone + linseed oil as dietary fats. Groups of 12 animals have been sacrificed at weanling or after 60 or 120 days of this dietary treatment. Body and brain weight, brain total lipids, phospholipids, cholesterol, cerebroside, fatty acid content and fatty acid composition have been evaluated. The diet rich in alphalinolenic acid (C 18:3 n-3) induced a significant increase of the n-3 polyunsaturated fatty acids (C 22:5 and C 22:6, n-3) in the brain, with respect to the other experimental conditions.

Animals↗
PubMed1984

Fatty acid composition of single brain structures following different alpha linolenate dietary supplementations.

Weanling female rats randomly divided into three groups were fed a basal alipidic diet added with 10% (w/w) corn oil, soybean oil or linseed oil. After thirty and ninety days of dietary treatment the rats were killed and the fatty acid composition of brain, optic nerve and visual cortex was determined. The results demonstrate a different sensitivity to the diet of the different structures examined and, for the linseed oil treated rats, a strong decrease in the proportions of the total (n-6 + n-3) polyunsaturated fatty acids in all the structures examined.

Animals↗
PubMed1983

Increased cyclic GMP content in confluent and serum-restricted heart cell cultures exposed to polyamines.

Cyclic AMP (cAMP) and cyclic GMP (cGMP) have been implicated as intracellular signals in the transition from a resting to a growing state. This suggestion comes from observations showing that the addition of growth promoting factors to quiescent cell cultures causes a rapid and transient decrease in cAMP and an increase in cGMP contents [9, 11] and that exogenous cAMP or cGMP congeners reduce or stimulate cell growth respectively [6, 13]. In view of this antagonistic effect elicited by the two nucleotides, it has been suggested that a fall in cAMP/cGMP ratio might be the triggering event for the initiation of cell proliferation [6]. Since polyamines correlate positively with active cell division [7], a possible involvement of these biogenic polycations in the regulation of cellular cyclic nucleotide contents is worthwhile investigating. Our previous reports have shown indeed that in different cultured cell types, spermine, spermidine and putrescine, at relatively low doses, are able to reduce cAMP content [3] by increasing cAMP-dependent phosphodiesterase activity (cAMP-PDE) [4] and to counteract the action of different cAMP-mediated effectors [3]. Besides endogenous polyamines seem to be involved in the cAMP-mediated induction of cAMP-PDE, as observed in heart cell cultures [4]. This report shows that the addition of each individual polyamine to confluent and serum-restricted heart cell cultures, while lowering cAMP content, induces an early and rapid increase of cGMP content by reducing the rate of its degradation.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1982

[Protection of essential fatty acids by vitamin E].

The protective role of vitamin E against free-radical-mediated oxidations is discussed. In spite of the presence of vitamin E in cell membranes, as structural complex with polyunsaturated fatty acids (PUFA) of phospholipids, the question arises whether high PUFA containing diets, producing high deposition of PUFA in the tissues, can nevertheless lead to peroxidations in the body. It has been suggested that large amounts of dietary PUFA increase the requirement for vitamin E and deplete its tissue stores, particularly when PUFA are discontinued in the diet, also because of their longer half-life time than tocopherols. However, in physiological conditions, linoleic acid up to 10% of caloric intake seems to have no effects on vitamin E requirement. In contrast, in essential fatty acid (EFA) deficient animals, also the addition of small amounts of dietary EFA, by resulting in a proportional increase in PUFA content of membrane structural lipids, is associated with an increased need for vitamin E. This becomes particularly important in the case of dietary fish oils or other poorly protected fats.

Animals↗
PubMed1980

Coenzyme Q10 levels in rat heart of different age.

CoQ10 is intrinsic to human tissues and is a vitamin, according to the basic science of nutrition. It is known that CoQ10, plays a role in the respiratory process, moreover it seems to be involved in the mechanism of blood coagulation. As a vitamin a deficiency of CoQ10 may be related to some disease, that is, first of all, a disease is bioenergetics. It has been demonstrated that during aging, other than a diminution of EFA (and an increase of palmitoleic and eicosatrienoic fatty acids), a decrease of about the 20-30% in the heart CoQ10 levels occurs in the rat. Perhaps these modifications may be intrinsic to the "biochemical" changes of aging.

Aging↗
PubMed1980

Biometabolic effects of different nutrients on embryonal cultures.

It has been valued the effects of different nutrients (glucose, phospholipids and ethanol) on the growth and morphology of chicken embryo cells, cultured in vitro by "pendent drop". Considering that the basal nourishing substratum used in these studies is the best medium that may be supplied to the cultures for the growth of this kind of tissues, the entity of damage induced by different nutrients has been shown. It may be said that the less negative effect is induced by 2.5% ethanol and by the association: "glucose + 2.5% ethanol", that the damage induced by only glucose seems to improve in presence of 2.5% ethanol, that in presence of phospholipids the cells appear all full of big lipid drops (especially in the condition: "phospholipid + ethanol") and that 5% ethanol deeply appears to impair and alter the cultures, as it was been observed in our previous experiences.

Animals↗
PubMed1979

Influence of phospholipids on the respiratory activity of embryonal heart cells cultured in vitro in presence of different ethanol concentrations.

The influence of phospholipids on respiratory activity of embryonal heart cells, trated with certainly harmful concentrations of ethanol, has been discussed. It has been concluded that when the cell is deeply impaired the administration of phospholipids does not seem to have positive effects. In this condition an irreversible morphological alteration has been induced.

Animals↗
PubMed1979

[Appraisal of the protein efficiency ratio of diverse protein concentrates].

In this report the biological value of new protein concentrates has been estimated. In growing rats the protein efficiency ratio, together with the load of liver and serum cholesterol, lipids and proteins, has been determined. It has been concluded that all the protein samples have a nutritional value at least like the older products made with proteins of milk.

Animals↗
PubMed1979

Effect of ethanol on respiratory activity of embryonal tissues.

By estimating the respiratory activity of various chicken embryonal organs we have noted that it was the highest for the kidney tissues and lower and lower for liver, brain and heart tissues. After the addition of ethanol to the culture medium we may conclude that ethanol 2,5% does not substantially alter the cellular respiratory activity, whereas ethanol 5% remarkably appears to inhibit it. In fact for this last condition the heart and kidney fragments, when are transplanted after 48 hours in "pendent drop", result rarely surviving.

Animals↗
PubMed1979

Effect of organ phospholipids on the growth of embryonal tissues cultured in vitro.

With regard to a set of studies about cellular nutrition, the effect of different amounts of phospholipids, extracted from various organs of calf (diencephalon, retina, cerebral cortex and heart), on normal embryonal chicken myocardium cultures has been tested. From the numerous observations we have made it is resulted that phospholipids, particularly at the highest levels, constantly decrease the culture migration velocity and this reduction is remarkably more accentuated in presence of 1.25%(0) heart phospholipids. Moreover in this condition the cells show a change in their morphology and appear all full of big lipid drops, perhaps in consequence of an alteration of the chemical-physical plasmalemma characteristics and a change in the membrane enzyme activities involving lipid metabolism too.

Animals↗
PubMed1979

Effect of a long term oral administration of a hypercholesterolic diet on rat liver substructures.

The effects of high cholesterol diets on ultrastructure morphologic alterations of rat liver have been investigated. It has been verified that these diets induce the biochemical and morphological damage, as well as death in a shorter time than alipidic or sole saturated lipid diets. Moreover it has been established that the anatomic irreversible damage appears at the last stage, just before death.

Animals↗