Phospholipid and fatty acid composition of lamellar bodies isolated from chicken lungs at different stages of development]

In order to elucidate whether the lamellar body content represents functional surfactant as soon as these bodies appear in lung epithelium during fetal development, lamellar bodies were isolated from lungs of Chicken at various developmental stages. Their content was analyzed and compared to extra-cellular functionnal surfactant. The results show that this content undergoes gradual changes in the phospholipid/protein ratio, as well as in the relative phosphatidylcholine amount. Thus, in the Chicken, nascent lamellar bodies do not represent the final form of extracellular surfactant.     

Oxygen consumption and biosynthetic function in perfused liver from rats at different stages of development

Changes in mitochondrial function were studied in perfused liver from rats aged 24 – 365 days. Oxygen consumption together with the rates of gluconeogenesis, urea synthesis and ketogenesis were determined. Basal mitochondrial respiration as well as the ability of the liver to synthesize glucose, urea and ketone bodies declined from 24- to 365-day-old rats. On the other hand, on transition from 24 to 60 days the liver oxidation rate of hexanoate, sorbitol and glycerol is enhanced, but not of ketone bodies or palmitate. Our results show that the transition from weaning to middle age is accompanied by defined changes in hepatic substrate oxidation. From the observed time course of the decrease in basal and substrate-stimulated oxygen consumption, it is concluded that in rat liver cells a decline in respiratory chain function, long-chain fatty acid and ketone body metabolism, gluconeogenesis and ureogenesis occurs at a relatively early life stage. Received 19 June 1998; received after revision 11 September 1998; accepted 11 September 1998     

Chromosome secondary constrictions in different stages of development

Zusammenfassung In den Metaphasen von embryonalen und neugeborenen Amphibien, Reptilien und Säugern wurde eine grössere Anzahl von Satelliten und anderen sekundären Strukturen beobachted als in solchen von ausgewachsenen Tieren. Dies kann bedingt sein durch eine grössere Anzahl von Cistronen der rDNS, die sich aktiv in den Zellen junger Tiere befinden.

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This work was supported by the Brazilian CNPq, FAPESP and FEDIB. The authors aknowledge the technical assistance ofL. F. Napoleone.     

Demonstration of a basal lamina in cocultures of thyroid cells and embryonal swine skin cells]

Porcine thyroid and embryo skin cells were isolated and cultured. Cultures from each kind of cells, as well as cocultures were fixed twice a week for electron microscopy. On day 8th a basal lamina like material appears only in the cocultures, along the basal plasmalemma of the reassociated thyroid cells. This amorphous material increases up to day 17th.     

Immunoglobulins in human fetal sera at different stages of gestation

Zusammenfassung Durch quantitative Immunodiffusion wurde der Gehalt an IgM, IgA und IgG in menschlichen Fötalseren untersucht. Der früheste Zeitpunkt, wo IgA entdeckt wurde, war bei einem prämaturen Embryo, der 41 cm lang war und 1680 g wog. In den Seren von am Termin geborenen Kindern konnte IgA in 37% nachgewiesen werden. IgG wurde in allen untersuchten Seren gefunden.

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Supported by a grant from the Sigrid Jusélius Foundation.     

Acid-base homeostasis and the thyro-parathyroid glands]

Chronic metabolic acidosis entails hyperparathyroidism and osteopathy. In order to elucidate the role of the thyroparathyroids in this bone lesion production the effects of acidic diet for 7 weeks were studied in parathyroidectomized (PTX), thyroparathyroidectomized (TPTX) and shamoperated (Sh-O) growing rats. In all animals urinary excretion of calcium, phosphate, ammonium and titrable acidity was similarly increased. The rise in hydroxyproline excretion and urinary 85-sr (that was injected previous to acidic feeding) was more marked in PTX and TPTX rats. Moreover, in these animals the serum calcium level was increased, the blood pH was decreased. According to these data, an acidic diet intake that is not sufficient to elicit a fall in blood pH of normal young rats can induce severe acidosis in chronically parathyroidectomized or thyroparathyroidectomized animals; moreover the bone resorption appears more marked. It is concluded that parathyroids are involved in the extra-cellular fluid defense mechanism against acidosis by a no bone resorptive mechanism. We hypothesize that the parathyroids permit the necessary and adequate supply of bicarbonates by the bone to maintain blood pH homeostasis.     

Effects of stress and adrenocorticotrophin administration on plasma corticosterone levels at different stages of pregnancy in the mouse

Summary Stress or administration of ACTH to pregnant mice gave rise to much higher plasma corticosterone levels in the second half of pregnancy than in the first half, suggesting that there may be increased adrenal sensitivity to ACTH or decreased metabolism of corticosterone during the second half of pregnancy.     

Effects of stress and adrenocorticotrophin administration on plasma corticosterone levels at different stages of pregnancy in the mouse.

Stress or administration of ACTH to pregnant mice gave rise to much higher plasma corticosterone levels in the second half of pregnancy than in the first half, suggesting that there may be increased adrenal sensitivity to ACTH or decreased metabolism of corticosterone during the second half of pregnancy.     

Activity of phospholipases A and some lysosomal enzymes in rat testes at different stages of hypervitaminosis A

Summary Excess of vitamin A induces decrease of neutral phospholipase A₁ and A₂ activity in rat testes homogenates on the 4th day, and increase of -galactosidase activity on the 8th day of treatment. It is suggested that phospholipase A activity decrease is of great importance in development of testicular disorders, caused by disbalance of vitamin A.     

Distribution of calcitonin cells in the thyroid glands of normal adult rhesus monkeyMacaca mulatta

Summary The calcitonin cells of adult rhesus monkeyMacaca mulatta are located in the central region of thyroid along the median axis. The anterior and posterior poles, the isthmus and peripheral regions of thyroid are completely devoid of C cells. The parathyroid also lacks C cells.     

Cyto-immunochemical detection of gamma endorphin in swine adenohypophysis]

An immunserum was prepared from gamma endorphin and its specifity was checked by the indirect method. It was tested on hypophysis which were taken from Pigs since birth till 3 months old. The anterior lobe as well as the intermediate lobe have reacted. The same cells were positive in the anterior lobe and recognized the anti-ACTH, anti-beta MSH and anti-beta LPH immunserums. However, the reaction was more labile than with these last immunserums and it was varying with the delay of fixation after the death and the penetration in the gland by the fixator.