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P Liscia

Publications and source records attributed to P Liscia.

7 recordsLinked to original sources
PubMed1998

Effects of moderate and intensive training on functional activity of central 5-HT1B receptors in the rat substantia nigra.

The efficacy of the selective 5-HT1B receptor agonist CP 93,129 in inhibiting the forskolin-stimulated adenylyl cyclase activity in the rat substantia nigra was reduced by both moderate and intensive prolonged training compared with sedentary resting rats. The concentration-response curves of the agonist were shifted to the right with a sixfold increase of the half-maximal inhibitory concentration. A difference was observed between the two training exercises in regard to further changes in 5-HT1B receptor sensitivity induced by an acute restraint stress. This manipulation did not affect the functional response of the 5-HT1B receptors further in moderately trained rats, whereas an additional desensitization of the 5-HT1B receptors was observed in intensively trained rats. These results strongly suggest the existence of regulation mechanisms altering the functional efficacy of 5-HT1B receptors and, accordingly, affecting the serotonergic activity, since 5-HT1B receptors modulate the neuronal release of the amine.

Adenylyl Cyclases↗
PubMed1987

Fluid shifts and endocrine responses during lower body negative pressure and dynamic arm exercise.

The use of lower body negative pressure (LBNP) is proposed as a means of reducing the effect of spaceflight on body water loss by stimulation of renin angiotensin aldosterone system (RAAS) activity. Seven subjects were successively submitted to LBNP exposure, arm cranking physical exercise, and to a combination of both procedures (LBNP + arm cranking) in order to check whether this combination enhances RAAS activity. The results showed that exposure to 40 min of LBNP to a level of -40 mm Hg was a more potent stimulus for renin secretion than submaximal and maximal arm cranking. The combination of LBNP with exercise does not further enhance the RAAS activity induced by LBNP alone. These data suggest that the fluid shift toward the lower body induced by LBNP counteracts triggering of renin secretion due to physical exercise.

Adult↗
PubMed1985

Hypertension induced by repeated exposure to high sustained +Gz (HS + Gz) stress.

The purpose of this study was to determine whether repeated exposure to high sustained +Gz (HS + Gz) stress induced persistent changes in the functional state of the cardiovascular system. Three groups of rabbits--centrifuged, restrained, and control--were studied. After being placed in the restraining system of the centrifuge, the animals were submitted three times in a row to 8-9 +Gz sustained for 40 s. This exposure was repeated three times a week for 3-6 weeks. Restrained animals were not exposed to HS + Gz. Control animals were not restrained. The two types of stress (centrifuge + restraint; restraint alone) determined the appearance of two types of arterial hypertension. Systolic arterial pressure (AP) and left ventricular pressure (LVP) significantly increased in restrained animals. The function of the cardiovascular system was more perturbed in centrifuged rabbits since the significant changes affected not only systolic AP and LVP but alos systemic diastolic AP and the maximum rate of rise of LVP. The myocardium of rabbits repeatedly subjected to HS + Gz exposures, except for those that suffered a fracture of the lumbar spine, was significantly glycogen-depleted.

Adenosine Diphosphate↗