Suitability of urethane anesthesia for physiopharmacological investigations in various systems. Part 2: Cardiovascular system

Summary Urethane produces a level of surgical anesthesia characterized by preservation of a number of cardiovascular reflexes. When the proper route of administration is used, and the use of unnecessarily high doses is avoided, urethane anesthesia appears to be suitable for a number of investigations at cardiovascular level. However in certain types of studies involving pharmacological stimulation of peripheral adrenoceptors urethane affects markedly the magnitude of the response under study.     

Suitability of urethane anesthesia for physiopharmacological investigations. Part 3: Other systems and conclusions

Summary The suitability of urethane anesthesia for physiopharmacological experiments in various systems is briefly reviewed. Urethane anesthesia appears to be suitable for various types of studies on respiratory function and on reflex activation of motility of the urinary bladder and some sections of the intestinal tract. However, urethane produces a variety of potentially disturbing side-effects at endocrine and renal level.     

Suitability of urethane anesthesia for physiopharmacological investigations in various systems. Part 1: General considerations

The suitability of urethane anesthesia for physiopharmacological investigations is reviewed. Total dose administered and route of administration are recognized as factors having a great influence on both resting parameters and biological responses to drugs. A peculiar characteristic of urethane is represented by its ability to induce a surgical plane of anesthesia without affecting neurotransmission in various subcortical areas and the peripheral nervous system. This makes urethane a suitable general anesthetic for studying neural function in both central and peripheral nervous systems and accounts for the preservation of a number of reflex responses in urethane-anesthetized animals.     

Suitability of urethane anesthesia for physiopharmacological investigations in various systems. Part 2: Cardiovascular system

Urethane produces a level of surgical anesthesia characterized by preservation of a number of cardiovascular reflexes. When the proper route of administration is used, and the use of unnecessarily high doses is avoided, urethane anesthesia appears to be suitable for a number of investigations at cardiovascular level. However in certain types of studies involving pharmacological stimulation of peripheral adrenoceptors urethane affects markedly the magnitude of the response under study.     

Suitability of urethane anesthesia for physiopharmacological investigations. Part 3: Other systems and conclusions

The suitability of urethane anesthesia for physiopharmacological experiments in various systems is briefly reviewed. Urethane anesthesia appears to be suitable for various types of studies on respiratory function and on reflex activation of motility of the urinary bladder and some sections of the intestinal tract. However, urethane produces a variety of potentially disturbing side-effects at endocrine and renal level.     

Fluid and protein clearance in the rat endometrium. Part II: Ultrastructural evidence for the presence of alternative,non-lymphatic clearance mechanisms in the rat endometrium

Summary In the rat endometrium, resident macrophages and exudate phagocytes ensure proteolysis by means of phagocytosis, macro-and micropinocytosis. Using exogenous tracer particles no ultrastructural evidence could be obtained for the occurrence of endometrial prelymphatics. It is suggested that the free tissue fluid may be drained via the fenestrated (probably venous) blood capillaries.Supported by a grant from the Nationaal Fonds voor Wetenschappelijk Onderzoek-Fonds voor Geneeskundig Wetenschappelijk Onderzoek (Belgium).