Effects of chronic low-dose ethanol intake on sexual behavior in rats.

The effects of 8-week ethanol intake (3% v/v in drinking water) on the sexual activity of male rats were investigated during three experimental sessions with 15-day intersession intervals. Chronic ethanol consumption did not significantly influence any copulatory parameter during the three experimental sessions. The evaluation of ultrasonic emission during sexual behavior showed that rats treated with ethanol exhibited a significant increase of the postejaculatory vocalization length during the third test session. These results indicate that the chronic intake of low doses of ethanol, which does not induce either tolerance or dependence, only slightly affects the motivational state of male rats during sexual activity.

Chronic low doses of ethanol affect brain protein kinase C and ultrasonic calls in rats.

Few studies have investigated neurobehavioral and neurochemical consequences of chronic consumption of low doses of ethanol. The present study shows that in rats exposure to 3% ethanol (v/v in drinking water) for 2 months decreased both calcium-dependent and -independent protein kinase C (PKC) activities in the cortex and in the hippocampus. This treatment also reduced ultrasonic calls (UCs), an index of emotional and motivational states of the animal. In addition, at cortical level of ethanol-treated rats, we observed a correlation between calcium-dependent activities and UCs. These results suggest that nonaddicting doses of ethanol affect brain PKC activities and that this enzyme may be involved in the ethanol modulation of emotional and motivational behaviors.

Atrial natriuretic factor antagonises angiotensin II--induced vasopressin release in rat subfornical organ.

The coexistence of Atrial Natriuretic Factor (ANF) and Angiotensin II (Ang II) receptors in the subfornical organ suggested that ANF may influence the action of Ang II at this level. To test this hypothesis the effect of ANF pre injected into subfornical organ (SFO) on Ang II-induced vasopressin release was investigated in rats. ANF blunted vasopressin release elicited by circulating Ang II. This study indicates SFO as one of the main sites at which ANF-Ang II interactions occur.

Ultrasonic vocalization as an indicator of emotional state during active avoidance learning in rats.

Adult male rats subjected to a two-way avoidance task emitted ultrasonic vocalizations (20-30 kHz) both during the presentation of the conditioned stimulus and the intertrial interval. The rate of ultrasonic calling decreased during the 75-trial session indicating that acquisition of the conditioned avoidance response (CAR) was inversely correlated with the rate of vocalization. The rate of acquisition of the CAR was most rapid in those rats that did not emit any vocalization during learning. These data suggest that ultrasonic calling during stressful situations may be sensitive indicator of underlying emotional states that interfere with the acquisition of a complex task.

Synthesis and pharmacological evaluation of perhydropyrrolo [3,4-c]pyridine derivatives.

Several N,N'-bis-alkyl-perhydropyrrolo[3,4-c]pyridines 4 and the corresponding bis-quaternary derivatives 5 have been prepared through standard methods starting from the bicyclic dilactam 2. Compounds 4 and 5 were evaluated for their inhibitory properties against acetylcholine (ACh), 1,1-dimethylphenyl piperazinium iodide (DMPP), 5-hydroxytryptamine (5-HT) and histamine (H1), and the guinea pig isolated ileum. Pharmacological data indicated that the strongest anticholinergic activity was shown by the dibenzyl amine 4 g, which among the tested molecules presented also a rather potent effect at the ganglia level, resulting about three times more potent than hexamethonium as ganglionic blocking agent. The preliminary SAR coming from the analysis of the pharmacological results are presented and discussed.

[Mechanogram profile of the guinea pig intestine. The refractory phase]. / Profilo del meccanogramma di intestino di cavia. La fase refrattaria.

In smooth muscle cells, when they are contracted for long time by carbachol, after washing a relaxation occurs. Thereafter if they are stimulated again, a less intense and late contraction develops after a long period of latency. Several drugs used as inducers of the long contraction produce a crossed refractoriness; therefore it would seem that the refractoriness does not depend upon receptors. The block of Na-K pump, elicited by a digitalic agent, potentiates the dose ratio; conversely the latency reaches normal values if a saline solution, with a low NaCl content, is used. On the basis of our results, we hypothesize that during the first phase of the induction very high levels of Na accumulate into the smooth muscle cell; these high Na concentrations, present for few minutes also after the washing, could be responsible for the refractoriness. Since an increase of Ca in the saline solution potentiates the refractoriness, the usefulness of calcium salts, in treating the hyperexcitability of smooth muscle cells could be due to this strengthened effect.

[Anti-thirst action of propranolol]. / Azione antidipsica del propranololo.

A reduction of the thirst was observed one hour after intramuscolar injection of 0.3 mg/kg propranolol in the rat; this effect was not observed with higher doses. According to work hypotheses, small doses could act blocking renal beta-adrenergic receptors: the stopped renin emission reduces angiotensin production that is the basic factor of thirst. The AA hypothesize that the lack of the effect in response to higher doses of propranolol can be explained through a different action of this drug which antagonizes the first one.

[Interference of extraneous solutes in the iontophoresis of salicylic acid across the skin]. / Interferenza di soluti estranei nella iontoforesi dell'acido salicilico attraverso la pelle.

It has been analyzed the possibility to modify the cutaneous ionthophoresis of drugs by means of an original apparatus through which experiments are performed on isolated rat skin. The test drug employed as the salicylic acid (SA). The presence of parasite ions decreases the passage of SA through the skin with an effect which is proportional to the salt concentration. The sodium salicylate is transferred less than SA. It has been analyzed the effect of drugs increasing the skin permeability like dimethylsulfoxide (DMSO) and dimethylformamide (DMF). DMSO in combination with SA facilitates the SA cutaneous ionthophoresis, while DMF does not.