Brain nucleic acid content during the estrous cycle in the rat

Résumé Le contenu total du RNA, DNA et le poids sec de certaines parties prélevées au cerveau sont resté constants durant les différentes étapes du cycle oestral.

---

---

Deceased.     

Variations of nucleic acid content in the salivary glands ofDrosophila hydei during late larval development

Résumé On a suivi la synthèse de l'ARN et de l'ADN dans les glandes salivaires chezDrosophila hydei. Les données biochimiques sur la teneur en acides nucléiques à différents moments du développement larval semblent indiquer que la synthèse d'une très grande quantité d'ARN a lieu dans les glandes avant la différentiation du troisième stade et aussi avant le commencement de la dernière vague de polyténisation des chromosomes.

---

---

This investigation was supported by C.N.R. (Grant No. 115-0263-01222). We are very indebted to Prof.B. Battaglia for his interest to our work.     

Changes in the sialic acid content of chick thymus and bursa of Fabricius during age-involution

Summary The sialic acid content of both thymus and bursa of Fabricius during their growth and involution phases in chick has been reported in this study. It is observed that the sialic acid concentration is very high in 1-week-old chickens. The concentration subsequently decreases to a significant level and rises again prior to the onset of involution. In the postinvolution period, a more or less minimal and constant level is maintained. The role of sialic acid in cellular activities of thymo-bursal system has been discussed.Supported by the University Grants Commission, Govt of India under the scheme Support to Research.     

Changes in the sialic acid content of chick thymus and bursa of Fabricius during age-involution.

The sialic acid content of both thymus and bursa of Fabricius during their growth and involution phases in chick has been reported in this study. It is observed that the sialic acid concentration is very high in 1-week-old chickens. The concentration subsequently decreases to a significant level and rises again prior to the onset of involution. In the post-involution period, a more or less minimal and constant level is maintained. The role of sialic acid in cellular activities of thymo-bursal system has been discussed.     

Gliogenesis during embryonic development in the rat

Summary With the aid of thymidine-H³ autoradiography gliogenesis in the rat brain was seen to start during embryonic stages, which might continue into the postnatal stages of development. Gliogenesis followed a caudo-rostral gradient closely following neurogenesis. Ependymogenesis was found to occur in parallel with gliogenesis.Supported by research grants NS-08817 and CA-14650 from N.I.H.     

Gliogenesis during embryonic development in the rat

With the aid of thymidine-H3 autoradiography gliogenesis in the rat brain was seen to start during embryonic stages, which might continue into the postnatal stages of development. Gliogenesis followed a caudo-rostral gradient closely following neurogenesis. Ependymogenesis was found to occur in parallel with gliogenesis.     

Mass and RNA content of rat spinal anterior horn neurones during postnatal development

Zusammenfassung Die postnatale Entwicklung der Trockenmasse und des RNS-Gehaltes isolierter spinaler Vorderhornzellen der Ratte wurden mit quantitativen Methoden untersucht, wobei eine postnatale, 3,6fache Vermehrung der Nervenzellmasse und eine 4,2fache des RNS-Gehaltes beobachtet wurde. Bereits im Alter von einem Monat werden nahezu endgÜltige Werte erreicht.     

Lipid and phospholipid content and fatty acid composition of the chick lung during embryonic development

Summary The evolution of total phospholipid, phosphatidylcholine and phosphatidylethanolamine content of chick lung during embryonic development is in good agreement with morphological data. Saturated fatty acids are predominant. A sex-linked difference is observed in the evolution of phosphatidylcholine.     

Changes in the protein kinase C activity or rat sternomastoid muscle during development and after denervation

Summary The relationship between the activity of protein kinase C (PKC) and muscle innervation was explored in the rat sternomastoid muscle (SM) from day 18 of gestation (E18) to adult age. Between E18 and birth, PKC activity rose 5-fold, and during the day after birth, diminished to a level characteristic of the mature muscle. The rise chiefly occurred in the neural part of the muscle, in both the membrane and the cytosol fractions. Between E18 and day 5 after birth, the ratios of membrane to cytosol PKC activity rose from 0.5 to 10 and 3 respectively in the neural and aneural parts of the muscle. Denervation of adult SM reduced PKC activity by half in the membrane fraction of the neural part but did not significantly change it in the membrane or cytosol fractions of the aneural parts. These results suggest that innervation plays an important part in determining the level of PKC activity in muscle.     

Changes in the protein kinase C activity or rat sternomastoid muscle during development and after denervation

The relationship between the activity of protein kinase C (PKC) and muscle innervation was explored in the rat sternomastoid muscle (SM) from day 18 of gestation (E18) to adult age. Between E18 and birth, PKC activity rose 5-fold, and during the day after birth, diminished to a level characteristic of the mature muscle. The rise chiefly occurred in the neural part of the muscle, in both the membrane and the cytosol fractions. Between E18 and day 5 after birth, the ratios of membrane to cytosol PKC activity rose from 0.5 to 10 and 3 respectively in the neural and aneural parts of the muscle. Denervation of adult SM reduced PKC activity by half in the membrane fraction of the neural part but did not significantly change it in the membrane or cytosol fractions of the aneural parts. These results suggest that innervation plays an important part in determining the level of PKC activity in muscle.     

Changes in ascorbic acid content in denervated frog gastrocnemius muscle

Zusammenfassung Nach Denervierung des Gastrocnemius beim Frosch waren die Konzentrationen der l-Ascorbinsäure, Dehydro-l-Ascorbinsäure (DHA) und Diketoguloniksäure (DKA) im Nieren- und Nebennierengewebe unverändert. DHA und DKA fehlten, während ihre Konzentrationen in der Leber trotz Ascorbinsäurezunahme gleichmässig verteilt waren.     

Lipid and phospholipid content and fatty acid composition of the chick lung during embryonic development.

The evolution of total phospholipid, phosphatidylcholine and phosphatidylethanolamine content of chick lung during embryonic development is in good agreement with morphological data. Saturated fatty acids are predominant. A sex-linked difference is observed in the evolution of phosphatidylcholine.     

Influence of the oestrous cycle on the nucleic acid and protein content of the pineal gland

Zusammenfassung Gesamteiweiss und RNS der Zirbeldrüse steigen während der Dioestrusphase bei Ratten an. DNS bleibt während des ganzen Cyclus konstant.

---

---

Acknowledgment: The authors are indebted to MissUte Schmidt for her excellent technical assistance.