RESUMO
Unsymmetrical dimethylhydrazine (UDMH, heptyl) and its derivatives are used in the rocket and space industry as components of rocket fuel. UDMH is a highly toxic compound exhibiting irritant, hepatotoxic, and neurotoxic properties. In this study, the toxic effect of heptyl on isolated rat heart and lymphatic vessels was demonstrated. Acute exposure to UDMH leads to vasoconstriction of the coronary vessels of the isolated heart and pronounced stimulation of isolated lymphangions starting from the concentration of 10-4 M. The changes are dose-dependent. After exposure to UDMH in high concentrations (10-2 M), the changes in the functional parameters became irreversible. The obtained results provide evidence for the organ-specific effect of UDMH on visceral muscle organs.
Assuntos
Dimetilidrazinas , Vasos Linfáticos , Animais , Dimetilidrazinas/toxicidade , RatosRESUMO
We studied the effect of endomorphin-1 on isolated mesenteric lymphatic vessels in rats. It was found that endomorphin-1 caused a dose-dependent increase in the contractile activity of lymphangions, which was associated with stimulation of intracellular calcium depots. The observed effect of endomorphin-1 in isolated lymphatic vessels has a complex mechanism; it depends on the concentration of the applied peptide and is probably determined by its interaction with non-opioid receptors.
Assuntos
Cálcio/metabolismo , Vasos Linfáticos/efeitos dos fármacos , Vasos Linfáticos/metabolismo , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/metabolismo , Oligopeptídeos/farmacologia , Receptores Opioides mu/metabolismo , Animais , Masculino , RatosRESUMO
We have studied the effect of Ð -endorphin (an endogenous opioid peptide) on the functional characteristics of isolated rat heart. In physiological concentrations (6.3 X 10-10 M) Ð -endorphin induces a negative inotropic effect, accompanied by a slight decrease in the heart rate, and has no effect on the perfusion pressure of the coronary vessels. It is shown that the effect of Ð -endorphin is mediated by 5-opioid receptors. ATP-dependent K+-channels contribute the greatest contribution to the implementation of the effect of Ð -endorphin on the isolated heart of a rat. The role of voltage-dependent K+-channels and NO-mediated mechanisms in the implementation of the effects of Ð -endorphin is minor.
Assuntos
Frequência Cardíaca/efeitos dos fármacos , Coração/fisiopatologia , Contração Miocárdica/efeitos dos fármacos , beta-Endorfina/farmacologia , Animais , Masculino , Técnicas de Cultura de Órgãos , Canais de Potássio/metabolismo , Ratos , Receptores Opioides delta/metabolismoAssuntos
Endotélio Vascular/fisiologia , Histamina/farmacologia , Linfonodos , Vasos Linfáticos , Mesentério/anatomia & histologia , Contração Muscular , Animais , Difenidramina/farmacologia , Relação Dose-Resposta a Droga , Endotélio , Agonistas dos Receptores Histamínicos/farmacologia , Antagonistas dos Receptores Histamínicos H1/farmacologia , Linfonodos/efeitos dos fármacos , Linfonodos/fisiologia , Vasos Linfáticos/anatomia & histologia , Vasos Linfáticos/efeitos dos fármacos , Vasos Linfáticos/fisiologia , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , RatosRESUMO
The role of regulatory peptides is the least explored part in the field of humoral regulation of lymphatics. In this paper we continue a systematic investigation of their effects on the lymphatic vessels of various animals. The effect of thyroliberin was studied on bovine mesenteric lymphatics. The isolated lymphatics contractility and smooth muscle cell electrical activity were investigated. Thyroliberin in ultra low concentrations (1 x 10(-13)-1 x 10(-18) M) exerts a considerable stimulating effect. The mechanism of the theroliberin ultra-low concentrations action and a possibility of the medical usage of the obtained results, are discussed.
Assuntos
Sistema Linfático/fisiologia , Músculo Liso/fisiologia , Hormônio Liberador de Tireotropina/fisiologia , Animais , Bovinos , Eletrofisiologia , Técnicas In Vitro , Sistema Linfático/efeitos dos fármacos , Masculino , Mesentério , Contração Muscular , Músculo Liso/efeitos dos fármacos , Hormônio Liberador de Tireotropina/farmacologiaRESUMO
Glucocorticoids were found to affect the membranes of lymphatic vessels' myocytes. Mechanisms of this action were studied.
