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An experimental model in rats was evaluated to differentiate the effects between Copper deficiency and Molybdenosis. Sixty weaning rats (30 male and 30 female) received a diet with 70% complete powder milk (1 ppm Cu) and 30% maize meal (0.8-1.5 ppm Cu). Three experimental groups received the following mineral supplementation: copper deficiency (40 ppm Fe), molybdenosis (40 ppm Fe + 40 ppm Cu + 500 ppm Mo) and control (40 ppm Fe + 40 ppm Cu). The animals were weighed each 14 days. At 70 days of treatment were sacrificed. Blood and liver were sampled for analyzing hematocrit, ceruloplasmin activity and Cu and Mo liver concentration. Copper deficiency group had less serum ceruloplasmin activity. Cu and Mo liver concentration were higher in the animals with molybdenosis. We concluded that when Cu levels are higher than minimum requirement, feeding with high Mo, do not affect ceruloplasmin activity. In addition, high Mo liver concentration allows us to elucidate effects "per se" of molybdenosis.

Cumulative dose-response curves were produced for the effect of different adrenergic agonists on the contractions of uterine strips from natural estrous and ovariectomized rats. Isoproterenol, norepinephrine and phenylephrine inhibited uterine spontaneous contractions, whilst methoxamine stimulated them. The inhibitory influences were blocked by propranolol and the excitatory effect of methoxamine was abolished by phentolamine. However, the sensitivity of the rat uterus to beta- and alpha-adrenergic agonists varied depending on the hormonal state i.e. strips from rats in natural estrus were more sensitive to inhibitory effect of beta-agonist than were those from ovariectomized animals. On the contrary, the apparent potency and the efficacy of an alpha-agonist (methoxamine) was higher in ovariectomized uterine strips than in those from estrous rats. Indomethacin, at a concentration known to inhibit the endogenous synthesis of prostaglandins, depressed the spontaneous activity of strips from spayed rats and prevented the response to methoxamine, whereas in strips from natural estrous rats, the drug was unable to modify either the spontaneous contractions or the stimulating action of methoxamine. In addition in the presence of threshold doses of PGE1, PGE2 and F2 alpha the dose-response curve to methoxamine shifted to the left for uterus from ovariectomized animals. The results suggest that uterine strips from estrous rats have more affinity to the effect of beta-adrenergic agonists, whereas those from spayed animals were more sensitive to the effect of an alpha-adrenergic agent. Also the effectiveness of an alpha-adrenergic agonist, methoxamine, appears to be related to unaltered tissue prostaglandins.

The profile of spontaneous contractions as well as the influences of prostacyclin (PGI2) on the motility of human ovarian veins obtained during the estrogenic phase of the sex cycle were explored. The preparations exhibited a distinct phasic activity, which progressively decreased as isolation time progresses, dissapearing almost completely following more than two hours. PGI2 produced a biphasic influence on quiescent preparations. After the threshold is attained lower concentrations caused depression of tone whereas higher ones enhanced the basal tone and induced phasic contractile cycles. Phentolamine reduced markedly the stimulating influence of PGI2 but had no action on the inhibitory effects, whereas propranolol failed to alter either the excitatory of the depressive action. The results suggest a participation of alpha-adrenoceptive-mediated mechanisms in the stimulatory effect of PGI2. On the other hand, PGI2 may be of importance in the regulation of venous flow and the spontaneous or PGI2-induced contractions could play a role in the counter current mechanism between veins and arteries in the ovarian pedicle.