1,720,976 research outputs found
Circadian variations of serum myoglobin in healthy subjects.
No full textIn order to evidentiate whether a circadian rhythm of the myoglobin serum concentration is present in humans, we measured serially the myoglobin levels in blood samples of 21 healthy subjects (10 females and 11 males), at bed rest, by means of a sensitive and accurate radioimmunological method. The data obtained were then evaluated according to the single and mean cosinor analysis, to assess the presence of a significant circadian rhythm. Eighteen of the 21 subjects showed a significant circadian rhythm. The calculated equation for the mean cosinor was: Y = 19.12 + 4.09 cos (15t-128.24) and the F-value for the zero amplitude test was 19.9 (p less than 0.001). Our data demonstrate that circadian variations of myoglobin serum concentration are likely to occur in humans. These findings strongly emphasize the need to take the time of sample collection into account when employing serum myoglobin as a marker for muscle damage
Changes in endocrine atrial rat cardiocytes during growth and aging: an ultrastuctural, morphometric and endocrinological study
No full textThe effects of age on atrial natriuretic factor (ANF) metabolism were studied in male Sprague Dawley rats by standard radioimmunological procedures, transmission electron microscopy, and ultrastructural morphometry. Plasma atrial natriuretic peptide (ANP) levels increased during growth (1-month-old rats: 64 +/- 8.7 pg/mL; 2-month-old rats: 105 +/- 8.1 pg/mL) and did not change thereafter. Immunoreactive (ir)-ANP concentration increased significantly in senescent rats, both in the right (12-month-old rats: 254 +/- 33 ng/mg; 24 month-old: 415 +/- 77 ng/mg) and left atrium (226 +/- 30 and 498 +/- 60 respectively). The ultrastructural morphological features of the endocrine cardiocytes of senescent rats were the presence of a few lysosomal structures and atrial specific granules of higher electron-density. Ultrastructural morphometry studies did not reveal any significant increase in the number or in the mean individual volume of atrial specific granules, compared with young adult rats. In conclusion, unlike younger rats, morphometric data in older and senescent rats show that atrial granularity may not necessarily change together with atrial ir-ANP contents; ir-hormone assay findings show that senescent rats have ANP plasma levels within the norm, and a much larger hormone store in atrial tissue
Radioimmunological determination of the MB-isoenzyme of creatine-phosphokinase: comparison with immuno-enzymatic procedures.
No full textModificazioni istologiche ed istochimichedel corticosurrene di Ratto albino,dopo somministrazione cronica di corticotropina sintetica-1-39
No full textEffects of the administration of thyroid hormone on the plasma levels of atrial natriuretic peptides and on atrial myoendocrine cells in the rat: an immunochemical, ultrastructural, and stereological study.
No full textThe effects of an altered thyroidal status on the levels of immunoreactive (ir-)
atrial natriuretic peptide (ANP) in serum and in the right and left atria, as
well as on the subcellular structures of atrial myoendocrine cells were explored
in groups of male Sprague Dawley rats given the vehicle or triiodothyronine in
the toxicological dose-range (50 micrograms/100 g bw/day) for 0,5, 1,2,4,7 or 14
days. Plasma levels of ir-ANP were 30% higher in T3-treated rats compared with
controls at 0,5 and 1 day after hormone administration and then decreased to
levels 30-40% lower than controls at days 2 and 4 to rise again above control
values on day 7 and 14. Atrial ir-ANP levels decreased at first both in the right
and in the left atria with different latencies (1 and 2 days, respectively) and
rose back towards control levels by day 4. Changes in the numerical density of
specific granules followed a parallel temporal pattern. An increased in the
individual volume of the granules followed was also observed. Investigation into
the circulatory effects of T3 administration showed that the heart rate was
increased by hour 12 after hormone administration (simultaneously with the early
rise in plasma ir-ANP levels) and that blood pressure was increased by day
2.(ABSTRACT TRUNCATED AT 250 WORDS
Abnormal circulating levels of muscle enzymes and myoglobin in hypothyroidism: their significance and usefulness in follow-up of replacement therapy of the metabolic disorder
No full textEffect of T3 administration on ANP plasma levels and atrial content in the rat: biochemical and morphometric investigation.
No full textMorphological and histochemical research on the adrenal cortex of the albino rat, after treatment with synthetic ACTH 1-39.
No full textEffetti di restrizione dietetiche ad azione anti-invecchiamento sulle alterazioni senili della struttura e della funzione endocrina dei cardiociti atriali del ratto.
No full text- …
