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Biomedical subjects

A Sakai

Publications and source records attributed to A Sakai.

At least 523 records · Page 29Linked to original sources
PubMed1976

The liver as a privileged site for parathyroid alloimplanation in the rat.

It has been suggested that the liver suppresses the immune response to alloantigen. This hypothesis was tested utilizing parathyroid implantation into the liver and muscles of inbred rats. Recipients were parathyroidectomized and, after significant hypocalcemia, donor parathyroids from minor histoincompatible rats were implanted either in liver or in thigh hamstring. In one experimental group second-set grafting also was tested. Graft survivals were evaluated by (1) duration of functional response (DFR), the period of time during which the serum calcium level remained above the postparathyroidectomy baseline, (2) maximal response (MR), the proximity of the postimplantation calcium peak response to the normal preparathyroidectomy calcium level. Parathyroid implants survived significantly longer in the liver compared to the muscle, only when implanted across minor histocompatible barriers. It is suggested that the liver may contain an inhibitor, capable of suppressing the lymphocytes and thus suppressing immune response, which can be demonstrated when the histocompatibility barrier is weak.

Animals↗
PubMed1976

The liver and immune responses. I. Regional lymph node response in rats to injection of semi-allogeneic adult liver cells.

Regional lymph node response in F1 hybrid rats in injection of parental adult liver cells was investigated. More than a 10-fold increase in node weight over the uninjected control node was observed on day 11 following injection of 60 X10(6) parental liver cells. The node weight gain was both dose and time dependent although 10 times more liver cells were required than the lymphocyte. Injection of either irradiated (600 rads) or cultured (30 days) liver cells did not reduce the reactivity. The liver cells prepared from 18-day-old fetuses, 70% hepatectomized or portacaval shunted rats were all shown to be reactive, the latter being far superior. This phenomenon is immunological since only parental (semi-allogeneic) but not syngeneic liver cells gave the reaction although a hybrid resistance cannot be denied. Possible mechanisms underlying this phenomenon are discussed.

Aging↗
PubMed1976

Liver regeneration and lymphocyte activation.

A 70 per cent partial hepatectomy in the rat results in a massive deoxyribonucleic acid synthesis not only in the remaining liver cells but also in the lymphoid organs. Serum factor present in the rat after hepatectomy stimulated both hepatocytes and lymphocytes in culture. Lethally irradiated rats, followed by a partial hepatectomy, could be restored their regeneration ability only when the lymphocytes taken from rats after hepatectomy were injected. A hypothesis is that the replications of the regenerating liver cells and the antigen stimulated lymphocytes are triggered by a common pathway, probably through adenosine 3':5'-cyclic phosphate activation.

Animals↗