A small dose of apomorphine counteracts the deleterious effects of middle cerebral artery occlusion in different models.

The present manuscript investigates in two animal species by using two different experimental models of middle cerebral artery occlusion (permanent and transient), the neuroprotective effects of the dopamine receptor agonist apomorphine. These effects were evaluated by measuring the infarct volume and by counting muscle strength at different time points following the ischemic insult. Apomorphine at the dose of 3 mg/Kg when adminsitered at two hours following the occlusion of the middle cerebral artery was able to reduce significantly the infarct volume in the cortex of mice and the ischemic volume of the basal ganglia perfused by the perforant branches of the middle cerebral artery in the rat. In this latter case the behavioral evaluation (i.e. muscle strength) was preserved most effectively in the contralateral side at 24 and 72 hours. The present findings contribute to foster the concept that DA agonists might be useful in the treatment of cerebral ischemia. At the same time the behavioral improvement induced by DA administration following basal ganglia ischemia may be interpreted as the effects of an authentic disease modifying effect rather than a simple symtomatic relief due to a potential loss of DA containing axons in the basal ganglia. These data add on previous evidence showing analogous effects induced by the DA precursor L-DOPA. Apart from providing an evidence of a neuroprotective effect induced by increased DA stimulation the present data call for further studies aimed at comparing the effects of apomorphine with other DA agonists. In fact the quinoline moiety of apomorphine was claimed to protect neurons from a variety of insults independently from a DA agonist activity. The induction of protein clearing pathways appears to be potentially relevant for these effects.

Gender-dependent variability of signal-averaged electrocardiogram in acromegaly.

Ventricular late potentials are obtained by signal-averaged surface electrocardiography. Late potentials in normal subjects may be influenced by physiological elements such as gender, height and body mass index. Considering that growth hormone (GH) hypersecretion is able to markedly alter different anthropometric variables, we studied the relation between these elements and the late potentials of 22 acromegalic patients. Males registered higher absolute QRS duration and LAS40 (low-amplitude signal) and, on the opposite, lower RMS40 (root mean square) in comparison to females; QRS duration and LAS40 seem to depend, however, on the different anthropometric variables, since their normalization with height and lean body mass (LBM) abolishes gender-dependent differences. On the contrary, the persistence, among males, of lower RMS40 in respect to females even after normalization for height, LBM and insulin-like growth factor 1 values makes it likely that the latter ECG variable is independent of the anthropometric ones and from the disease's activity. Moreover, males appear to be more vulnerable to GH heart-harming activity.