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Biomedical subjects

G Orlandini

Publications and source records attributed to G Orlandini.

At least 91 records · Page 5Linked to original sources
PubMed1985

Why is [Ca2+]i increased in blood cells in primary hypertension?

In order to explore a previously observed association between raised blood cell cytosolic calcium [Ca2+]i and primary hypertension, resting levels of [Ca2+]i in the Milan hypertensive rat strain (MHS) were measured. The [Ca2+]i was increased significantly at 7 weeks in MHS (116 +/- 8 versus 93 +/- 6 mumol/l, P < 0.005, n = 7) and non-significantly at 5 weeks (109 +/- 7 versus 85 +/- 9 mumol/l, n = 5). In Okamoto-Aoki spontaneous hypertensive rats (SHR), calcium fluxes were measured with Quin 2 in platelets and lymphocytes. Calcium influx was measured during calcium-pump inhibition either with vanadate or ATP-depletion. Influx was increased in vanadate-treated (but not in ATP-depleted) cells of SHR. This suggests an ATP dependence of calcium influx in blood cells which is more pronounced in SHR. Calcium efflux was determined when the influx was stopped by external EGTA. Calcium efflux was [Ca2+]i-dependent and was moderately increased in SHR. The faster efflux in SHR was due to higher [Ca2+]i. The [Ca2+]i-dependency of calcium efflux was comparable in SHR and Wistar-Kyoto (WKY) rats. These results suggest that a slight but significant rise of cytosolic calcium occurs in blood cells in primary hypertension. In Okamoto-Aoki SHR this rise was due to a higher calcium entry rate.

Aminoquinolines↗
PubMed1984

Intracellular free [Ca2+] in circulating lymphocytes of spontaneously hypertensive rats.

In the light of previous reports suggesting a common abnormality of Ca handling in most tissues of hypertensive humans and rats, we applied a novel technique using the fluorescent probe Quin 2 for measurement of cytosolic free Ca2+ in lymphocytes of spontaneously hypertensive rats (SHR). (Ca2+)i is increased in SHR (122.1 +/- 7.4 nM) versus normotensive Wistar-Kyoto (WKY) control rats (81.1 +/- 6.3 nM) Membrane exchange, as challenged by varying the extracellular Ca concentration over a 10(5)-fold range proved to be relatively unimportant in regulating (Ca2+)i and did not significantly affect the difference between SHR and WKY. Catecholamines and ouabain had no appreciable effect on (Ca2+)i. The mechanisms of increased (Ca2+)i in SHR lymphocytes remain to be fully elucidated.

Animals↗
PubMed1982

[Effect of acute administration of verapamil on various metabolic parameters in healthy humans].

Calcium-antagonist drugs have been used for sometime in various forms of cardiac disease. Some of these molecules, in the initial phase of administration, show a net increase in the FFA liberation. So far it is not certain whether this behavior also refers to other molecules. Therefore we studied the action of verapamil on FFA, on glycemia and on insulinemia. The drug was administered orally (single dose of 80 mg) and intravenously (single dose of 10 mg in 45 m'). 15 healthy subjects were examined, 7 women and 8 men, aged from 19 to 45. These subjects were also used as controls, administered with placebo. Our findings show that this calcium-antagonist drug is not capable of interfering with the studied metabolic parameters.

Administration, Oral↗
PubMed1980

[Repeated venesection in pseudoporphyria cutanea tarda of hemodialysis (author's transl)].

Cutaneous syndrome called porphyria tarda-like of dialyzed patients may involve risk of infections besides aesthetic complications. We have described a very serious case of which the therapeutic problem has become oppressive inducing various attempts, already used for porphyria cutanea tarda or completely new. The only treatment which brought improvement in symptomatology was repeated venesection. Aminoacidic loss during dialysis appears as possible pathogenetic hypothesis for this syndrome.

Amino Acids↗
PubMed1980

Effects of human growth hormone on blood polyamines in hypopituitarism.

Blood levels of polyamines were evaluated in hypopituitary patients after i.m. injection of human growth hormone (hGH). After hGH administration polyamine concentration increased significantly in the first 60 minutes. The concentration of spermidine and spermine increases more in patients previously untreated or treated intermittently with hGH than in patients under continuous treatment. The results suggest that in human as well as in experimental models, polyamines could be involved in the growth process and that hGH probably stimulates polyamine synthesis.

Adolescent↗
PubMed1979

[Concentrations of polyamines in maternal and umbilical-cord blood and in the amniotic fluid during normal human pregnancy and in feto-placental insufficiency].

Blood maternal polyamines during normal pregnancy exhibit an important augmentation around the 10th and the 34th-38th week, and a minor increase between the 20th-25th week of pregnancy. These peaks coincide with extremely important metabolic events in the feto-placental unit such as maximal growth rate in the placenta and fetus, respectively. The levels of polyamines measured from the 38th to 41th week in the blood of the umbilical cord are higher than in the blood of the mother. Putrescine, spermidine and spermine are not detectable when measured in the non-hydrolized amniotic fluid during normal pregnancy, instead a band with a lower Rf than spermine is present. In case of feto-placental insufficiency polyamine concentration in maternal blood are well below the normal values, from the 34th to 38th week of pregnancy. Such a behaviour appears for umbilical cord blood at the 38th and 39th week. Also the unknown polyamine of the amniotic fluid undergoes evident modification in feto-placental insufficiency. These results show that blood polyamines of the mother are probably of fetal origin, and that modified pattern of maternal polyamines may indicate an insufficient body growth of the fetus.

Adult↗
PubMed1979

[Serial evaluation of blood polyamines in children treated with growth hormone].

Blood polyamines were evaluated in normal children of various ages (from infancy to adolescence). Polyamines show a distinctive pattern: maximal values were observed during infancy; they decrease during childhood and again increase at puberty. After i.m. injection of Human Growth Hormone (HGH), polyamine concentrations increase significantly in the first 60 minutes. Polyamines increase more in patients previously untreated or treated intermittently with HGH than in patients under continuous treatment. The results suggest that in humans as well as in animals, polyamines could be involved in the growth processes and that the effect of HGH probably consists in a stimulation of polyamine synthesis.

Adolescent↗