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Biomedical subjects

R G Kemp

Publications and source records attributed to R G Kemp.

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

Lymphoid cell adenylate cyclase activity after x-irradiation and cortisone treatment.

Cortisone injection and x-irradiation of normal mice lead to extensive destruction of thymus and spleen lymphocytes. The lymphocytes resistant to these treatments have basal adenylate cyclase activities that are the same as or slightly lower than the cells of untreated animals. On the other hand, the ability of the cyclase of the cortisone-resistant and radioresistant lymphocytes to respond to stimulation by epinephrine is greatly diminished. The results provide an explanation for the previously observed lack of epinephrine sensitivity of the cyclase of lymphoid cells of immunodeficient pituitary dwarf mice and suggest that the depressed lymphoid cell population of the dwarf is the result of an inability to recover from stress-related lymphoid involution. It is also suggested that the more mature population of lymphoid cells of normal mice is less responsive to hormonal influences.

Adenylyl Cyclases↗
PubMed1975

Changes in lymphoid cyclic adenosine 3':5'-monophosphate metabolism during murine leukemogenesis.

Cyclic adenosine 3':5'-monophosphate (cyclic AMP) levels were slightly increased in preleukemic AKR mouse thymus cells, compared with nonleukemic thymus cells, but were markedly reduced in leukemic cells. Adenylate cyclase activity rose during the preleukemic and leukemic phases of leukemogenesis. Although the drop of epinephrine-induced stimulation of thymus adenylate cyclase in the preleukemic phase was probably age related, there was an additional decrease of adenylate cyclase activation by epinephrine in leukemic cells. Cyclic AMP phosphodiesterase activity was slightly higher in preleukemic cells and more than fourfold AKR thymus. These observations suggest that cyclic AMP phosphodiesterase is largely responsible for the low levels of cyclic AMP in leukemic cells. Significant changes in cyclic AMP metabolism are already detectable before neoplastic cells may be found in the thymus.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1974

Thymus adenylate cyclase activity during murine leukemogenesis.

Activity of thymus adenylate cyclase was more than three times higher in leukemic AKR mice than in nonleukemic AKR mice and CBA mice. Preleukemic AKR mice that had no evidence of leukemia but were expected to soon develop the disease exhibited similarly elevated activities of thymus adenylate cyclase.

Adenosine Triphosphate↗