RESUMO
Granulocytopoietic response to lithium carbonate (Li+) in rat was eliminated completely by N-cholinergic blocking agent, and independently by alpha-1-adrenergic antagonist. A link between these two contradictory events is explained by release of acetylcholine from the cholinergic preganglionic nerve endings in adrenal medulla triggered by Li+, and subsequent discharge of catecholamines (CA) from medullar chromaffin cells, which on their part activate adrenergic receptors of alpha-1 class on hematopoietic progenitor cells. Respectively, granulocytopoietic response to Li+ is blocked by cholinergic N-blocking agent at the level of adrenal medulla, and by the alpha-adrenergic blocking agent at the level of the hematopoietic cells proper. The stimulatory action of Li+ on granulocytopoietic cells is indirect, while is mediated by CA release from adrenal chromaffine cells. At the initial stages of leukocyte restitution in the acute myelotoxic leucopenia relative increase in "large" lymphocyte fraction (Lge) preceding the increment in granulocyte counts is evident. In this fraction of lymphocytes peripheral blood progenitor cells (PBPC) are expected.
Assuntos
Acetilcolina/metabolismo , Catecolaminas , Células Precursoras de Granulócitos/efeitos dos fármacos , Carbonato de Lítio/administração & dosagem , Medula Suprarrenal/efeitos dos fármacos , Antagonistas de Receptores Adrenérgicos alfa 1/administração & dosagem , Animais , Benzoatos/administração & dosagem , Catecolaminas/metabolismo , Antagonistas Colinérgicos/administração & dosagem , Células Cromafins/efeitos dos fármacos , Ciclofosfamida/toxicidade , Doxazossina/administração & dosagem , Células Precursoras de Granulócitos/citologia , Leucopenia/induzido quimicamente , Masculino , Ratos , Receptores Colinérgicos/metabolismoRESUMO
Sensitivity to phenylephrine, isoproterenol, serotonin, oxytocin, acetylcholine and barium chloride of vas deferens uterus und fundus strip was studied comparatively in hepatectomized and sarcoma-45, sarcoma-M1, Walker carcinosarcoma and Zajdela ascites hepatoma bearing rats. The contractile response to monoamines and oxytocin was considerably lower or absent at certain periods after hepatectomy or tumour grafting. Effects of biogenic amine antagonists were also substantially altered. The response to isoproterenol, acetylcholine and barium chloride remained unchanged. Apparently a selective alteration of a response of visceral smooth muscles mediated through alpha-adrenergic and D-serotonin receptors occurred not only during the tumour growth but also in the case of active (extensive) proliferation of the normal tissue.
Assuntos
Carcinoma 256 de Walker/fisiopatologia , Epinefrina/fisiologia , Neoplasias Hepáticas Experimentais/fisiopatologia , Fígado/fisiologia , Músculo Liso/efeitos dos fármacos , Receptores Adrenérgicos/efeitos dos fármacos , Receptores de Serotonina/efeitos dos fármacos , Sarcoma Experimental/fisiopatologia , Animais , Feminino , Fundo Gástrico/efeitos dos fármacos , Hepatectomia , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/fisiopatologia , Transplante de Neoplasias , Ratos , Receptores de Catecolaminas , Fatores de Tempo , Útero/efeitos dos fármacos , Ducto Deferente/efeitos dos fármacosAssuntos
Aminas Biogênicas/análise , Neoplasias Experimentais/análise , Receptores de Superfície Celular/análise , Túbulos Seminíferos/análise , Testículo/análise , Útero/análise , Animais , Carcinoma 256 de Walker/análise , Feminino , Indóis/farmacologia , Masculino , Transplante de Neoplasias , Ratos , Receptores de Superfície Celular/efeitos dos fármacos , Sarcoma Experimental/análise , Túbulos Seminíferos/efeitos dos fármacos , Antagonistas da Serotonina/farmacologia , Fatores de Tempo , Contração Uterina/efeitos dos fármacosRESUMO
The proliferative response of secretory cells of parotid glands to isoproterenol could not be observed in tumour-bearing mice, while in normal mice a ten-fold increase was usually observed. Mice with subcutaneous allografts of normal tissue (tail fragments) demonstrated sensitivity similar to normal mice. Apparently, a lack of sensitivity in tumour-bearing mice is characteristic of the tumour-host interaction. According to electron microscopic cytochemical data the adenylate cyclase activity is not changed in the mentioned cells of the tumour-bearing mice. It is supposed that lack of sensitivity is due to an alteration of certain properties of some other components of the beta-adrenergic system.