RESUMO
The rat pituitary cell line, MtT/SM, has the characteristics of somatomammotrophs. The cells secrete both prolactin (PRL) and growth hormone (GH). We examined the effects of cytokines such as leukaemia inhibitory factor (LIF), interleukin 6 (IL-6), oncostatin M and interleukin 11 on the secretion of these hormones by the cells. These cytokines stimulate proliferation of the cells and inhibit the secretion of PRL by 70-80% and that of GH by 50%. They induce tyrosine phosphorylation of STAT3 in the cells. The cells containing PRL or GH decreased at 48 h after treatment of the cells with LIF or IL-6. These results suggest that the LIF/IL-6 family of cytokines inhibits the functions of mammotrophs and somatotrophs in the pituitary gland.
Assuntos
Hormônio do Crescimento/antagonistas & inibidores , Hormônio do Crescimento/metabolismo , Inibidores do Crescimento/farmacologia , Interleucina-6/farmacologia , Linfocinas/farmacologia , Neoplasias Hipofisárias/metabolismo , Prolactina/antagonistas & inibidores , Prolactina/metabolismo , Animais , Divisão Celular/imunologia , Proteínas de Ligação a DNA/metabolismo , Hormônio do Crescimento/biossíntese , Humanos , Imuno-Histoquímica , Interleucina-11/farmacologia , Fator Inibidor de Leucemia , Oncostatina M , Peptídeos/farmacologia , Fosforilação , Neoplasias Hipofisárias/imunologia , Neoplasias Hipofisárias/patologia , Prolactina/biossíntese , Ratos , Ratos Endogâmicos F344 , Fator de Transcrição STAT3 , Transativadores/metabolismo , Células Tumorais CultivadasRESUMO
1. Serum and sputum concentrations of cefoxitin were measured at fixed intervals following a one hour drip infusion of 2 g to a total of three patients with chronic respiratory tract diseases. The peak levels in serum were found to be 142.1-273.6 microgram/ml at the end of the infusion and those in sputum were found to be 0.92-2.30 microgram/ml at 2 to 4 hours after initiation of the infusion. 2. Cefoxitin was administered to a total of five patients with chronic respiratory tract infections who had failed to respond to the previous treatments with conventional antibiotics. The results were that in one case the therapeutic effect was judged as excellent, in three cases as good, and in one case it was difficult to evaluate. In all cases, there was no significant abnormality indicative of side effects regarding clinical symptoms and laboratory tests of renal and hepatic functions. In a view of the findings stated above, it is considered that cefoxitin is a new antibiotic which can be used for the treatment of chronic respiratory tract infections.
