1. Homogenization of mouse kidneys or livers in 0.25m-sucrose buffered with tris-acetate, pH7.3, resulted in a decreased rate of proteolysis within isolated heterolysosomes containing injected (125)I-labelled albumin when these particles were incubated at 35 degrees C. Proteolysis in mouse kidney or liver heterolysosomes isolated from homogenates made in 0.25m-sucrose buffered at pH7.3 was stimulated by pH5 buffer or by additions of ATP. 2. A greater inhibition of proteolysis was produced by including bicarbonate or pH8 borate buffers in the incubation media, and this inhibition was also reversed by ATP. 3. Other nucleoside triphosphates were not as effective as ATP, but GTP and ITP were more effective than CTP or UTP. ADP, AMP, or adenosine 3':5'-cyclic monophosphate were completely without effect. 4. Although ATP prevented some heterolysosome breakage in media containing bicarbonate, the primary effect appeared to be to promote proteolytic activity. 5. These observations are consistent with the presence of a proton pump in the heterolysosome membrane, which functions to maintain intralysosomal pH in alkaline media.

Adenine Nucleotides↗

PubMed1972

Measurement of low level environmental tritium samples.

Explore the source record for details and available documents.

Radiation Monitoring↗

PubMed1972

Gynaecological problems of childhood.

Explore the source record for details and available documents.

Adolescent↗

PubMed1971

Nutrition in refugee camps.

Explore the source record for details and available documents.

Adolescent↗

PubMed1971

Toxicity of folic acid.

Explore the source record for details and available documents.

Amines↗

PubMed1971

Effect of folic acid by mouth on cerebrospinal fluid homovanillic acid and 5-hydroxyindoleacetic acid concentration.

Administration of 30 mg folic acid by mouth caused a significant fall in cerebrospinal fluid homovanillic acid concentration in 11 subjects. There was no significant change of 5-hydroxyindoleacetic acid concentration. The fall was less marked in five patients on anticonvulsant medication and failed to reach statistical significance. Neither homovanillic acid nor 5-hydroxyindoleacetic acid concentrations changed significantly when 15 mg folic acid was given in divided dosage for one, two, and four weeks. The effect appeared to be related to the height of serum-folate levels reached and to be independent of cerebrospinal fluid-folate levels, which did not change significantly. Possible mechanisms and their potential therapeutic application are discussed.

Administration, Oral↗

PubMed1971