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S Partanen

Publications and source records attributed to S Partanen.

At least 91 records · Page 5Linked to original sources
PubMed1975

Histochemical observations on uptake of L-dopa into endocrine cells of the rat pituitary gland during the postnatal development.

The uptake of L-dopa into the cells of the adenohypophysis of the rat was studied during the postnatal development and at adult age using the formaldehyde-induced fluorescence method (FIF). The cells taking up L-dopa were classified by Alcian blue-PAS-Orange G staining. The correlation between the cells taking up L-dopa and those containing tryptophyl-peptide was estimated during the postnatal period and in adult rats. The cells containing tryptophyl-peptide were demonstrated using fluorescence induced by treatment with combined formaldehyde and acetyl chloride vapour. The following observations were made: 1) Great majority of the cells taking up L-dopa did not contain tryptophyl-peptide. Thus the accumulation of L-dopa into the cells of pars distalis is not due to accumulation of L-dopa into the cells by the same transport mechanism as the amino acids for tryptophyl-peptide. 2) Of the cells taking up L-dopa in the adult rats 96% were chromophobes, 2.0% acidophilic cells (somatotrophs and cells producing prolactin), 0.9% R-mucoid cells (corticotrophs), and 1.2% S1- and S2-mucoid cells (gonadotrophs and thyrotrophs). At 10 and 25 days' age the relative numbers of the cells taking up L-dopa were about the same. 3) Pretreatment with nialamide caused only a slight increase in the number of the cells taking up L-dopa. The decrease in the number of the cells uptaking L-dopa of the pars distalis, which takes place after 5 weeks' age is thus not caused by the increased MAO-activity. 4) Strongly chromophilic cells did not take up L-dopa. At the light of our results it seems evident that L-dopa is taken up by the chromophobic cells when these differentiate into chromophilic cells. The accumulation of L-dopa may be a sign of an active transport of amino acids into the cells. The accumulation of L-dopa into the chromophobic stellate and follicular cells may reflect their metabolic activity. These cells probably have an important role in the production of the hormones of the pars distalis.

Adrenocorticotropic Hormone↗
PubMed1975

Demonstration of catecholamines in peripheral adrenergic nerves in stretch preparations with fluorescence induced by aqueous solution of glyoxylic acid.

Fluorescence induced by aqueous solution of glyoxylic acid and formaldehyde-induced fluorescence of catecholamines were compared for the demonstration of peripheral adrenergic nerves in stretch preparations. Glyoxylic acid was better than formaldehyde for the demonstration of the adrenergic nerves. On the other hand, the formaldehyde was better than glyoxylic acid for the demonstration of biogenic amines in cell bodies.

Animals↗
PubMed1975

Fluorescence histochemical observations on the uptake and metabolism of tryptophan in the endocrine cells of the hypophysis.

The present work was undertaken to study the significance of the uptake of precursors of biogenic amines, L-dopa and 5-hydroxytryptophan, in the cells of the pars distalis of the mammalian hypophysis. The results of our own earlier studies suggested that L-dopa and 5-hydroxytryptophan may be taken up by the cells of the pars distalis which possess in their cell membranes the system for active transport of amino acids. In the present study, an effort is made to demonstrate the uptake of the amino acid, tryptophan, which is generally used for the protein synthesis. It was observed that after the administration of tryptophan the small cells of the pars distalis exhibited specific formaldehyde-induced fluorescence characterizing tryptophan and its metabolites. It was also noted that after the administration of tryptophan blue fluorescence was observed in some cells of the pars distalis prior to formaldehyde vapour treatment. The blue fluorescence may be due to the presence of quinoline metabolites of tryptophan formed in the cells. This new observation offers good possibilities to study the metabolism of tryptophan at the cellular level. The results of the present work support the suggestion that L-dopa or 5-hydroxytryptophan is taken up by cells of the pars distalis which possess the mechanism for general active transport of amino acids in the cell membrane.

5-Hydroxytryptophan↗
PubMedDate not supplied

Developmental changes in the expression of neuronal ceroid lipofuscinoses-linked proteins.

Neuronal ceroid lipofuscinoses (NCL) form a distinct group of storage diseases where the normal development of the central nervous system is interrupted and neurons of the neocortex begin to degenerate. Mutations in genes encoding three lysosomal enzymes are the causes for three early-onset forms of NCLs: palmitoyl-protein thioesterase 1 (PPT1) is deficient in human infantile NCL, tripeptidyl peptidase 1 (TTP1) in late-infantile NCL, and cathepsin D in congenital ovine NCL. We wanted to compare the developmental expression profiles of these enzymes in rat brain. In conclusion, the PPT1 expression pattern differed from the two other lysosomal enzymes implicated in NCL diseases, thus suggesting a distinctive role for PPT1 in brain development.

Aminopeptidases↗
PubMedDate not supplied

Histochemically demonstrable phosphotyrosyl-protein phosphatase in normal human breast, in benign breast diseases and in breast cancer.

The activity of phosphotyrosyl-protein phosphatase enzyme was investigated by a histochemical method in the normal human breast and in breast diseases in order to evaluate its possible significance in the genesis and in the growth of benign and malignant epithelial proliferative. In normal human breast tissue only a weak enzyme activity was present. The activity was elevated in benign disease in actively proliferative lesions and in 71% of the cases of breast cancers. When enzyme activity of breast cancers was compared with the content of receptors for epidermal growth factor and insulin-like growth factor-I, no association was found. It is concluded that phosphotyrosyl-protein phosphatase is increased in actively proliferating human breast diseases. Thus the putative increase in phosphotyrosyl-proteins mediating benign and malignant epithelial proliferations is rather caused by an increase in protein-tyrosine kinase activity than by a decrease in phosphotyrosyl-protein phosphatase activity.

Breast↗
PubMedDate not supplied

Phosphotyrosyl-proteins in human breast cancer.

The content of phosphotyrosyl-proteins, substrates of protein tyrosine kinases, was evaluated by immunohistochemical staining in human breast cancers, and its relation to the prognostic factors of cancers was studied. Both protein tyrosine kinase activity and the content of various growth factor receptors and oncoproteins with this activity have been shown to be elevated in breast cancers. The magnitude of the increase has been reported to have prognostic significance; greater increases were associated with poorer prognostic factors of cancers and with shorter survival of patients. Immunohistochemical staining demonstrated a low level of phosphotyrosyl-proteins in normal human breast tissue and in 44% of breast cancers. In 56% of breast cancers the level of phosphotyrosyl-proteins was increased; however, these cancers did not differ from cancers containing a low level with respect to prognostic factors such tumor size, histological differentiation grade or axillary lymph node metastases. The increased content of phosphotyrosyl-proteins in the majority of human breast cancers further supports the observations that growth factor receptors and oncoproteins with tyrosine kinase activities are activated in these cancers. The content of phosphotyrosyl-proteins, however, has no relation to the prognostic factors of cancers.

Antibodies, Monoclonal↗