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I Ocrant

Publications and source records attributed to I Ocrant.

22 records · Page 2Linked to original sources
PubMed1988

Distribution of insulin-like growth factor II receptor immunoreactivity in rat tissues.

Antibodies specific for the insulin-like growth factor II (IGF-II) receptor were used to study its distribution in a number of rat tissues and cell lines in order to determine which cells might be responsive to local or circulating IGF-II. In cultured 18-54,SF and B104 neuroblastoma cells, plasma membrane and cytoplasmic staining corresponding to Golgi apparatus could be seen, consistent with the glycoprotein nature of this receptor. Antibody binding was also seen in the central nervous system, confined primarily to the choroid plexus, and the vascular and ependymal elements. Some staining was seen in the parenchyma of the brain, in addition to binding around nerve sheaths and axon bundles. There were high levels of immunoreactivity in all three lobes of the pituitary, including vascular and cellular elements. In liver, highest levels of immunoreactivity occurred in the sinusoidal cells. In lung, IGF-II receptor immunostaining was seen in the alveoli and around the bronchioles. Staining in kidney was observed in glomeruli, tubules, and Bowman's capsules. Lower levels of immunostaining were seen in skeletal muscle, located primarily around the muscle sheaths. Localization of IGF-II receptor to cells of known function in different tissues will help elucidate the role of this ligand-receptor system in regulating growth and metabolism.

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PubMed1988

Structural and immunohistochemical characterization of insulin-like growth factor I and II receptors in the murine central nervous system.

The description of the cellular localization of insulin-like growth factor (IGF) receptors in the central nervous system (CNS) remains incomplete, as do the descriptions of changes in their characteristics with respect to different developmental stages. We, therefore, performed affinity labeling studies in microsomal membrane preparations of adult and fetal rat brain and liver tissues with [125I]IGF-I and [125I]IGF-II. These studies demonstrated tissue- and developmental stage-specific structural variants of type I receptor alpha-subunits as well as type II receptors. The adult rat brain type I alpha-subunit had an apparent mol wt (Mr) of 127,000, whereas those of adult and fetal rat liver measured 140,000. Fetal rat brain microsomes, however, had two types of type I receptor alpha-subunits measuring 130,000 and 120,000 Mr. The larger subunit from fetal brain consistently migrated at an apparent Mr of 3,000, greater than subunits from adult brain. Both type I and II receptors were more abundant in fetal liver and brain than in adult tissues. Affinity labeling was also performed directly to monolayers of cultured fetal brain neurons and newborn astrocytes. These studies detected both type I and II receptors on the surfaces of both types of cells. However, only the high Mr (140,000) form of the type I alpha-subunit was detected in cultured CNS cells, suggesting that expression of low Mr variant receptors is altered in vitro. Type II receptors were demonstrated by immunohistochemistry in adult rat hypothalamic neurons. However, the majority of neurons did not react with type II receptor antibody. This finding implies that only a minority of hypothalamic neurons are capable of responding to IGF-II via type II receptors. On the other hand, all astrocytes had striking type II receptor immunoreactivity. This signifies a more general biological role for this receptor in astrocytes compared with neurons. These results suggest that different tissue-, developmental stage-, and cell-specific processes are mediated by IGF receptors and suggests new directions in which to explore potential biological actions for these receptor-ligand systems in the CNS.

Affinity Labels↗
PubMed1979

The effects of different conditions of organ culture on the survival of the mouse pancreas.

The effects of different conditions of organ culture on the viability of murine pancreatic tissues and, particularly, of pancreatic islets, was assessed by morphologic and histochemical analyses. High oxygen tension (1300 mm Hg), found previously to allow successful allogeneic thyroid transplantation, was toxic to pancreatic tissue. Low temperature (22 degrees C) was associated with better islet preservation than high temperature (37 degrees C). Hydrocortisone did not reduce the survival of pancreatic islets and did appear to preserve the acinar components. Fetal and neonatal pancreas responded similarly to the various organ culture conditions. These results have potential importance in guiding future transplantation experiments.

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