V. Cuomo

Ultrasonic vocalization in rat pups as a marker of behavioral development: an investigation of the effects of drugs influencing brain opioid system.

Early postnatal exposure to morphine significantly influenced the ultrasonic vocalization of rat pups removed from their nest. In particular, a significant decrease in the rate of calling, sound pressure level and range of frequency was found in morphine-treated animals; moreover, the duration of calls was significantly increased by morphine administration. Conversely, neither beta-casomorphins (beta CMS), which are opioid peptides derived from the enzymatic digestion of milk protein (beta-casein), nor an opioid antagonist, like naloxone, significantly affected ultrasonic emission. The results are discussed with particular reference to the role of the opioid system in separation distress-induced vocalization in young animals.

Relationship between plasma insulin and left ventricular mass in normotensive participants of the Gubbio Study

background There is substantial but not conclusive evidence that insulin resistance is related to left ventricular mass (LVM) in hypertensive individuals. To what extent this association is mediated by the relationship between plasma insulin and body size and build is still debated, and is poorly explored in nonhypertensive people.

Neurobehavioral changes produced by developmental exposure to benzodiazepines.

The results reported in this review show that prenatal and/or postnatal administration of benzodiazepines, at dose levels below those associated with overt signs of neurotoxicity, produces both short- and long-term alterations in rats. Most of these behavioral changes are characterized by altered activity patterns and emotional/motivational responsiveness to environmental challenges.

CHANGES IN THE FREQUENCY OF SPLENIC IMMUNOCOMPETENT CELLS IN RATS EXPOSED TO CARBON MONOXIDE DURING GESTATION

The aim of the present study was to evaluate whether prenatal exposure to relatively low concentrations of carbon monoxide (CO) may alter the frequency of splenic cells either in young (15-21 days) or in aged rats (18 months). Wistar female rats were exposed to 75 and 150 ppm of CO from day 0 to day 20 of pregnancy, respectively. The results show that prenatal exposure to 150 ppm of CO significantly decreases the number of leucocyte common antigen (LCA+) cells in 21 day old male rats, whereas other cellular populations, such as macrophages, Major Histocompatibility (MHC) II cells, T and B lymphocytes display only a trend towards a reduction without achieving statistical significance. The alterations in LCA+ cell frequency produced by gestational exposure to CO were reversible. These data further extend previous findings showing that rats prenatally exposed to moderate concentrations of CO exhibit subtle immunological changes in the absence of overt signs of toxicity.

Behavioural and biochemical effects in C57BL/6J mice after a prolonged treatment with the δ‐opiate antagonist ICI 154129

A long term treatment with the δ‐selective opiate antagonist NN‐bisallyl‐Tyr‐Gly‐Gly‐ψ‐(CH2S)‐Phe‐Leu‐OH (ICI 154129) produces an increase in the number of δ‐opiate binding sites, whereas the same treatment with the non selective opiate antagonist naloxone results in an enhancement of both μ‐ and δ‐binding sites. This biochemical effect in naloxone‐pretreated mice is paralleled by a more pronounced increase in locomotor activity induced by a challenge dose of morphine. In contrast, no difference in the effect of morphine was seen in ICI 154129‐pretreated mice with respect to control. These data suggest that the locomotor response to morphine in C57 mice is not mediated through δ‐opiate receptors.

Behavioural changes in offspring of rats exposed to diazepam during gestation

Primiparous pregnant Sprague-Dawley dams were administered a single daily s.c. injection of diazepam (0.1 and 1 mg/kg) or vehicle over gestation days 14-20. No differences in neonatal mortality and weight gain were found between the control and diazepam-exposed pups. Conversely, male pups prenatally treated with this benzodiazepine exhibited subtle behavioural alterations either during early postnatal life or during adulthood. In particular, a significant decrease in the locomotor activity of the diazepam-treated groups was found at the end of the second postnatal week (14-16 days). Furthermore, the administration of diazepam during gestation produced marked changes in the length of ultrasonic calls of rat pups removed from their nest. Finally, adult male rats (120 days of age) prenatally exposed to diazepam showed a notable impairment in copulatory activity as well as a significant decrease in the duration of ultrasonic (22 kHz) post-ejaculatory calls emitted during sexual behaviour. These findings suggest that late gestational exposure to diazepam induces both short- and long-term behavioural changes in rat offspring, changes characterized by altered activity patterns and emotional-motivational responsiveness to environmental challenges.