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Biomedical subjects

F Bertini

Publications and source records attributed to F Bertini.

At least 55 records · Page 3Linked to original sources
PubMed1982

In vivo and in vitro effect of cold on the degree of polymerization of tubulin in toad brain and testis.

The tubulin of both brain and testis of the toad Bufo arenarum was partially depolymerized when the animals were maintained on ice for 90 minutes or 17 hours. Recovery of the animals at room temperature restored the normal degree of polymerization in both organs. Normalization of the polymerization degree also occurred in organs separated from cooled animals and incubated in vitro for 90 minutes at 20 degrees C. When the organs were cooled in vitro, only testicular tubulin underwent depolymerization, and in a degree similar to that occurring by incubation at 20 degrees C. The results suggest that the mechanisms regulating tubulin depolymerization in vivo are different from those taking place in vitro.

Animals↗
PubMed1982

Effect of androgens on the activity of acid hydrolases in rat epididymis.

The enzymatic activity of 6 acid hydrolases was studied in rat epididymal homogenates following castration, testosterone replacement and during postnatal growth. Acid phosphatase and N-acetyl-beta-D-glucosaminidase activity decreased after castration and increased with hormonal treatment as well as during growth. Beta-Glucuronidase and cathepsin D activity increased during the involution of the organ and decreased or did not change with hormone treatment or during sexual maturation. Arylsulphatase and deoxyribonuclease did not recover normal activity after hormonal treatment. Their activities were particularly high in epididymal and rete testis fluid of normal animals.

Acetylglucosaminidase↗
PubMed1982

Lysosomal enzymes in cells separated from rat testis.

Fractions enriched with Sertoli cell (S), germ cells (G), and interstitial cells (I) were separated from rat testis after enzymic treatment and double filtration through nylon meshes. The fractions were analysed for protein content and for enzymic activity of 4 acid hydrolases known to be of lysosomal nature in other tissues. Acid phosphatase activity was preferentially recovered in Fraction G, the highest activity of beta-glucuronidase was found in Fraction I while the activity of aryl sulphatase and beta-N-acetyl-D-glucosaminidase was prominent in Fraction S. With the exception of acid phosphatase, the enzymes were mostly recovered in a subcellular fraction of whole testis homogenate separated between 600 and 27 000 g. The results may reflect the peculiar enzyme composition of the lysosomal apparatus of each cell type.

Acetylglucosaminidase↗
PubMed1981

The development of lysosomal apparatus. II. Incorporation, subcellular distribution, and intraparticulate hydrolysis of 131 I-albumin by liver of mice at perinatal stages.

Mouse fetuses at 15th and 18th day of gestation, and newborns aging 0, 5, 10, and 15 days were injected i.p. with 131 I-albumin (RISA). The degree of incorporation by liver and the intraparticulate hydrolysis of RISA in 27,000g x 10 min. particles increased after birth. By this time, changes in subcellular distribution of RISA and marker enzymes were also observed. Following an i.p. injection of India ink, numerous hepatic cells stained with carbon particles were observed at the light microscope from day 5 of life. The results suggest that the lysosomal apparatus acquires full capacity to incorporate colloidal particles and to degrade foreign macromolecules in the first week of life.

Acid Phosphatase↗
PubMed1981

Acid hydrolases in the epididymis of normal, castrated, vasectomized, cryptorchid and cryptepididymal rats.

With the aim of gaining knowledge about the lysosomal apparatus of the rat epididymis, four acid hydrolases were analysed in homogenates of the whole organ and, in other experiments, in separated segments: proximal and distal caput, corpus and cauda. The activities were similar to those in the liver, and they were 50% recovered in a cytosol of 43 000 g x 60 min. Ten days after castration all segments showed similar changes, the activities of beta-glucuronidase and cathepsin D increased above normal levels while those of DNAase and acid phosphatase were found slightly decreased. After vasectomy region I (caput and corpus) showed decreased beta-glucuronidase activity and increased acid phosphatase activity. The activity of cathepsin D increased in both regions. In cryptorchid rats (90 days) the epididymis greatly decreased in weight, the activities of acid phosphatase and DNAase slightly decreased in region II (cauda) and in region I, respectively. In the abdominal epididymis (90 days) only region II decreased in weight. DNAase activity decreased in region I while cathepsin D did so in both regions. The results showed that a) the enzymes behave quite independently from each other, suggesting the existence of a specific regulation for each of them b) there were characteristic changes in enzymatic activity for each experimental condition.

Acid Phosphatase↗
PubMed1978

The development of lysosomal apparatus. I. Lysosomal enzyme activities in the liver of mice at perinatal stages and those of their mothers.

The enzymatic activity of five acid hydrolases: acid phosphatase, arylsulfatase A, deoxyribonuclease, beta-glucuronidase, and cathepsin D, was assayed in fetal (fifteenth and eighteenth days of pregnancy) and neonatal (Days 0, 5, 10, and 15 post-partum) mouse liver. With the exception of cathepsin D, the activity increased around birth to levels varying according to the enzyme. Histochemical observations of other authors appear to justify, at least in part, the present results, which indicate that late days of fetal development and early neonatal life may constitute a transitional stage to full lysosomal enzyme functionality of the adult organ. The livers of the mothers were also assayed for the same enzymes. Each activity showed a peculiar pattern which was, in turn, different from that found in the liver of the litter for the same enzyme, probably as a cause of the metabolic requirement of the gland. The hypothesis that the lysosomes are heterogeneous in their enzyme composition is suggested by the variety of enzymatic patterns found in the liver of the litters and their mothers.

Acid Phosphatase↗
PubMed1978

Urate-oxidase in liver of oxonic acid treated mice.

Following a single intraperitoneal injection of oxonic acid, urate-oxidase inhibitor with optical and chromatographic properties of the injected drug was found in the supernatants of mouse liver homogenates. Maximal inhibitory activity of 40 000 g-20 minutes supernatants against Sigma urate-oxidase was found 30 minutes after injection, and it almost disappeared after six hours. In whole homogenates, urate-oxidase activity was found 50% inhibited at 30 minutes, and it returned to normal levels between 3 and 6 hours following injection. Urate-oxidase activity of resuspended nuclei-free 40 000 g particles from these homogenates showed a significative increase of activity over controls during the first three hours after injection, and it returned to a normal level between 3 and 6 hours after injection. There was, instead, no increase of activity in 40 000 g-20 minutes particles suspensions when these were separated from homogenates prepared from untreated mice and incubated with oxonic acid.

Animals↗
PubMed1975

Solubilization of particle-linked urate oxidase by different agents.

Urate oxidase was mostly recovered in a 40 000 g for 20 min subcellular fraction from conventional homogenated. Different agents were able to solubilize the sedimentable enzyme when tested on this crude peroxisomal fraction. The agents increased also total enzyme activity which was recovered in supernatants after centfiguation. If the possible effect of absorption to pellets is to be discounted, the enzyme was practically 100% extracted by six alternated freezing and thawing high alkaline pH, the detergent Hyamine 2389 and high ionic strength of calcium chloride. Triton X-100 was very effective in extracting proteins from the fraction, while it left most of the enzyme activity insoluble. It is suggested that the forces responsible for the integrity of the crystalloid, which was observed by other authors at the electron microscope, and to which the enzyme is believed to be related, are the electrostatic nature.

Animals↗