Browsing by Author "FORADORI, A"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    A PREPUBERTAL SURGE OF THYROTROPIN PRECEDES AN INCREASE IN THYROXINE AND 3,5,3'-TRIIODOTHYRONINE IN NORMAL-CHILDREN
    (ENDOCRINE SOC, 1991) MICHAUD, P; FORADORI, A; RODRIGUEZPORTALES, JA; ARTEAGA, E; LOPEZ, JM; TELLEZ, R
    The variations in plasma levels of TSH, T4, T3, and rT3, during the pubertal period, were studied in 647 school students from the urban area of Santiago in Chile (47% males and 53% females) with ages ranging between 7.5 and 15 yr. The subjects were grouped by age in consecutive intervals of 6 months each, and pubertal development was determined in every subject. TSH showed a significant increase, reaching a peak in the 9- to 9.5-yr interval. The same was found for T3 and T4, which reached a peak by 10 and 11 yr. The T4/T3 ratio did not show any significant variation with age. After 9.5 yr, a decrease in rT3 and increase in the T4/rT3 ratio was found. The TSH peak preceded the onset of clinical pubertal development, while the T3 and T4 peaks coincided with this onset. The variations in rT3 suggest an increase of peripheral conversion of T4 to T3. These transient events, not described until now, could be termed thyroidarche and could have a significant effect on pubertal growth and development.
  • Thumbnail Image
    Item
    PLATELET 5-HYDROXYTRYPTAMINE INCREASES WITH PLATELET AGE IN DOGS
    (GEORG THIEME VERLAG KG, 1991) MEZZANO, D; DELPINO, GE; MONTESINOS, M; GARCIA, ME; ARANDA, E; FORADORI, A
    Thrombocytopenia was induced in mongrel dogs by two mechanisms: immunologically, by intravenous injection of heterologous antiplatelet antibody, and non-immunologically, by circulating the blood through glass beads in anesthetized animals. The platelet content of 5-HT was monitored before and during the recovery of the blood platelet counts. This period is associated with the normalization of the mean platelet survival time and with a progressive increase in the mean age of the circulating platelet population. A continuous increment in platelet 5-HT closely followed the increase in platelet counts in both models of thrombocytopenia, and a strong correlation was found between the platelet age and 5-HT content. These findings support the concept that platelets accumulate 5-HT during their physiological aging process, contradicting the notion that a negative balance in 5-HT content results at the end of their physiological lifespan in circulation. These results are not in conflict with the concept that circulating platelets release and re-uptake 5-HT.
  • No Thumbnail Available
    Item
    UTERINE KALLIKREIN IN THE EARLY PREGNANT RAT
    (OXFORD UNIV PRESS INC, 1993) VALDES, G; CORTHORN, J; SCICLI, AG; GAETE, V; SOTO, J; ORTIZ, ME; FORADORI, A; SAED, GM
    Uterine homogenates of cycling and early pregnant Sprague Dawley rats and purified rat urinary kallikrein showed similar curves of displacement of I-125-kallikrein binding to a polyclonal antibody. Uterine kallikrein concentration measured by RIA was 8.7 +/- 2 SEM ng/g wet weight during the cycle (n = 6 in diestrus and metestrus) and 20.8 +/- 2 SEM (n = 7) ng/g wet weight on Day 7 of pregnancy (P7) (p < 0.001). On P7, kallikrein concentration was increased 12.4-fold in the implantation nodes, as compared to the interimplantation segments. Uterine homogenates of rats on P7, submitted to DEAE-cellulose chromatography and Sephadex gel filtration, yielded two fractions containing kallikrein immunoreactivity and kininogenase activity, with molecular masses that ranged from 120-125 kDa and 39-43 kDa, respectively. In the RIA, both fractions displayed parallelism with purified kallikrein. Enzymatic activity was expressed after activation by trypsin. It was inhibited by aprotinin, PMSF, p-amino-benzamidine, and leupeptin, but not by soybean or ovomucoid trypsin inhibitors. Kallikrein mRNA was demonstrated by reverse transcriptase/polymerase chain reaction in uteri of nonpregnant and P7 rats. These results show that rat uterus synthesizes one or more serine proteases that are immunologically and enzymatically related to tissue kallikrein. The increase of kallikrein in the implantation node on P7-determined both by an increment of whole uterus kallikrein content and a depletion of the interimplantation segments-suggests that kallikrein may play a role in the vasoactive changes of implantation.