Effects of Hypericum perforatum extraction on alcohol intake in Marchigian Sardinian alcohol-preferring rats.

The present study investigated the effect of acute intragastric (i.g.) administration of dry Hypericum perforatum extract (HPE), containing 0.3% hypericin, on ethanol intake in genetically selected Marchigian Sardinian alcohol-preferring (msP) rats. The i.g. administration of HPE, 125 or 250 mg/kg, induced a 30-40% reduction in ethanol intake in rats offered 10% (v/v) ethanol for 2 h/day. The effect of these doses was selective, since they modified neither food intake nor food-associated drinking; neither did the same doses modify the rat's gross behaviour in the open-field test. A dose of 500 mg/kg frequently induced immobility and a general suppression of ingestive behaviour. In rats offered 10% ethanol for 12 h/day, ethanol intake following treatment with 250 mg/kg HPE was significantly lower than that of controls for up to 10 h. The effect on ethanol intake was not related to the antidepressant-like effect of HPE revealed in the forced swimming test. In this regard, the effect on ethanol intake was observed after a single administration of 125 mg/kg, whereas the antidepressant effect was observed only after repeated treatment with doses higher than 125 mg/kg HPE. The i.g. administration of HPE, 250 mg/kg, did not affect blood-alcohol levels following i.g. treatment with 0.7 g/kg ethanol, the amount usually ingested in a single drinking episode; thus, the effect is not related to changes in the pharmacokinetics of ethanol. The present study shows that HPE markedly reduces ethanol intake in msP rats, without significantly modifying food intake.

[Effects of eledoisin on water intake induced by subcutaneous injection of hypertonic NaCl in the rat]. / Effetto della eledoisina sulla assunzione di acqua indotta da iniezione sottocutanea di NaCl ipertonico nel ratto.

Intracerebroventricular administration of eledoisin, the tachykinin peptide of the salivary glands of Eledone Moschata, exerts a potent and long-lasting inhibition of water intake induced by the subcutaneous administration of hypertonic NaCl in the rat. The inhibitory effect is statistically significant up to 6 hr following eledoisin treatment, while the 24 hr water intake in control and treated rats is essentially identical. The results of the present study demonstrate that the long-lasting effect is not due to increased renal excretion of the osmotic load, nor, likely, to larger production of metabolic water. Probably, eledoisin exerts an inhibitory effect of such a long duration by means of central actions which last well beyond its half-life, or, alternatively, by promoting an increased excretion of the osmotic load through elimination routes different from the kidney.

[Physalaemin-like N-terminal fragments of mammalian tissues, PHLIP-7 and PHLIP-8 do not modify drinking behavior and sodium appetite in rats]. / I frammenti N-terminali fisalemino-simili di tessuti di mammifero, PHLIP-7 e PHLIP-8, non modificano "drinking behaviour" e appetito per il sodio nel ratto.

PHLIP-7 and PHLIP-8, two peptides reproducing at least in part the N-terminal aminoacid sequence of physalaemin, have been identified in mammalian tissues. These peptides produce alterations of fighting behaviour in the mouse, but are devoid of any behavioural activity in the rat. This suggests that PHLIP-7 and PHLIP-8 have no affinity for brain receptors involved in the behavioural effects evoked by tachykinins in the rat, and that the brain of this animal is lacking in receptors for the N-terminal sequence of tachykinins.