Prenatal Amphetamine-Induced Dopaminergic Alteration in a Gender- and Estrogen-Dependent Manner.

Prenatal exposure to amphetamine induces changes in dopamine receptors in mesolimbic areas and alters locomotor response to amphetamine during adulthood. Sex differences have been reported in amphetamine-induced brain activity and stress sensitivity. We evaluated the effects of prenatal amphetamine exposure on locomotor activity, dopamine receptors and tyrosine hydroxylase mRNA expression in nucleus accumbens and caudate-putamen in response to amphetamine challenge in adult female and male rats. The role of estrogen in the response to restraint stress was analyzed in ovariectomized, prenatally amphetamine-exposed rats. Pregnant rats were treated with D-amphetamine during days 15-21 of gestation. Nucleus accumbens and caudate-putamen were processed for mRNA determination by real-time PCR. In nucleus accumbens, higher mRNA dopamine (D3) receptor expression was found in basal and D-amphetamine-challenge conditions in female than male, and prenatal amphetamine increased the difference. No sex differences were observed in caudate-putamen. Basal saline-treated females showed higher locomotor activity than males. Amphetamine challenge in prenatally amphetamine-exposed rats increased locomotor activity in males and reduced it in females. In nucleus accumbens, estrogen diminished mRNA D1, D2 and D3 receptor expression in basal, and D1 and D3 in ovariectomized stressed rats. Estrogen prevented the increase in tyrosine hydroxylase expression induced by stress in ovariectomized prenatally exposed rats. In conclusion, estrogen modulates mRNA levels of D1, D2 and D3 receptors and tyrosine hydroxylase expression in nucleus accumbens; prenatal amphetamine-exposure effects on D3 receptors and behavioral responses were gender dependent.

Effects of hypothyroidism on the mesenteric and omental adipose tissue in rats.

To characterize the influence of hypothyroidism on the endocrine activity of mesenteric and omental adipose tissue (MOAT) and the peripheral regulation of energy balance (EB) in rats, we analyzed food intake (FI); basal metabolic rate (BMR); locomotor activity; body weight (BW); serum hormone concentrations and the expression of their receptors in MOAT. We evaluated the morphology and differentiation of adipocytes. Hypothyroidism decreased FI, BMR and BW. The percentage of visceral white adipose tissue (WAT) depots and the morphology of adipocytes were similar to euthyroid rats. Serum leptin and adiponectin expression in MOAT were altered by hypothyroidism. The expression of Perilipin 1, HSL, UCP1 and PRDM16 was significantly lower in MOAT of hypothyroid animals. Hypothyroidism in rats leads to a compensated EB by inducing a white adipocyte dysfunction and a decrease in BW, BMR, FI and adipokine secretions without changing the percentage of WAT depots and the morphology of the MOAT.

Changes in plasma iron levels following Carboplatin administration.

Carboplatin-induced changes in plasma iron levels and the related erythropoiesis impairment were investigated in 32 neoplastic patients for a total of 64 courses of chemotherapy. Iron showed a significant increase over pretreatment levels starting from day 1 after carboplatin administration (p< 0.001). Return to pre-treatment levels was achieved on day 14. Hemoglobin decreased significantly on day 7 (p< 0.05) and further on days 14 and 21 (p< 0.001). In patients undergoing 3 consecutive cycles of chemotherapy, basal hemoglobin before the 2nd cycle was significantly lower than before the 1st (p< 0.05), whereas before the 3rd cycle the levels were similar to those before the 2nd. Hemoglobin time-course did not differ among the three cycles. No relationship was observed between maximum iron levels and hemoglobin at minimum levels, nor between pre-treatment hemoglobin levels and severity of chemotherapy-induced subacute anemia. These results suggest that neither pre-treatment hemoglobin nor the entity of iron increase are predictive of the need of blood transfusion. Moreover, the absence of correlation between iron increase and hemoglobin decrease suggests that the toxic block on erythroid maturation is not the only mechanism with which platinum compounds interfere with iron metabolism. It is possible that the bivalent platinum ion may displace competitively iron from its binding sites, either on proteins or on cells.

Hyperkalaemia during infusion of hyperosmolar amino acid solutions enriched with branched chain amino acids. Report of two cases.

We report two cases of unexplained hyperkalaemia during infusion of amino acid solutions enriched with branched chain amino acids. The increase in potassium levels developed 24 hours after starting infusion and normalization was obtained within 24 hours after stopping infusion. Acidosis, acute renal failure, concomitant cell destruction and haemolysis were excluded; antialdosteronic diuretics were not given. The authors hypothesize that hyperkalaemia could be due to a sudden increase in plasmatic osmolality caused by the hyperosmolarity (900 mOsm/l) of the solution, not counterbalanced by adequate ADH release owing to malfunctioning of hypothalamic osmoreceptors. At present this hypothesis is lacking in experimental proofs.