Effects of dopamine on whole kidney function and proximal transtubular volume fluxes in the rat

Summary The renal effects of dopamine were studied using clearance and micropuncture techniques in rats. Intravenous infusion of dopamine (4.7 · 10^–6 mol · kg^–1 · h^–1) increased glomerular filtration rate and renal blood flow. Renal blood flow was measured by an electromagnetic flowmeter. The increase in filtered fluid and sodium was nearly completely matched by increased tubular reabsorption. Thus, only a small rise in urine flow and in urinary sodium excretion was observed.The micropuncture experiments using the split oil droplet method of Gertz demonstrated a stimulation of the transepithelial fluid transfer after injection of dopamine (10^–4M) into the proximal tubular lumen. This effect was abolished by simultaneous injection of propranolol (10^–3 M) which, by its own, did not affect transtubular volume fluxes. It is concluded that dopamine, by stimulation of -adrenoceptors, may increase reabsorptive capacity of the proximal tubular epithelium independent of changes in renal hemodynamics.Supported by Deutsche Forschungsgemeinschaft     

Observations on surgical restoration of voice after laryngectomy

Evaluation of surgical restoration of voice following laryngectomy, with Staffieri’s method of neoglottis, has been made. The method is oncologically safe and about 30% of all laryngectomies qualify for this surgery. Pre-operative radio-therapy is no contra-in dication for this surgery and post-operative radio-therapy does not affect the final result. The duration of speech therapy required with this neoglottis is shorter compared to the development of oesophageal voice. The quality of this neo glottic speech is superior in acoustic, phonatory and socio psychological aspects.     

Total glossectomy: reconstruction and rehabilitation

Patients with carcinoma of the tongue including the base of the tongue who underwent total glossectomy in a period of just over ten years since January 1979 have been reviewed. Total glossectomy may be indicated as salvage surgery or as a primary procedure. The larynx may be preserved or may have to be sacrificed depending upon the site of the lesion. When the larynx is preserved the use of laryngeal suspension facilitates early rehabilitation and preserves the quality of life to a large extent. Cricopharyngeal myotomy seems unnecessary.     

Die Lymphgefäß- und Lymphknotenresektion bei malignen Tumoren des Larynx

Ohne Zusammenfassung     

Effect of inhibitors of prostaglandin synthesis on the furosemide action in the loop Henle of rat kidney

Inhibitors of prostaglandin synthesis such as indomethacin and meclofenamate may attenuate the diuretic response to furosemide. The purpose of the present study was to clarify whether an inhibition of furosemide's action in the loop of Henle is involved in this interaction. In a first set of experiments, the effect of indomethacin and meclofenamate on the diuretic response to furosemide was re-evaluated in anaesthetized rats. Single loops of Henle of rat kidneys were perfused in vivo in a second group of rats. Furosemide was added to the perfusion fluid and the effect of indomethacin (5 mg/kg i.v.) and meclofenamate (5 mg/kg i.v.) on furosemide's action in the loops was tested. In the absence of furosemide, indomethacin and meclofenamate did not significantly affect urine flow and sodium chloride excretion, or the loop's sodium and chloride reabsorption. Both prostaglandin inhibitors, however, significantly attenuated the diuretic effect of furosemide (1 mg/kg i.v.) and the inhibitory action of the diuretic, at a concentration of 10^–4 M, on the loop's sodium and chloride transport. The results identify the loop of Henle as a tubular site of interaction between furosemide and prostaglandin inhibitors. The interaction may be related to a furosemide-induced stimulation of renal prostaglandins.Parts of this study were presented at the spring meeting of the German Pharmacological Society, Mainz 1987 (Naunyn-Schmiedeberg's Archives of Pharmacology 335, R48, 1987)     

Meiosis and spermiogenesis in the testis of Salamandra salamandra (L.) (Amphibia, Urodela)

Meiosis and spermiogenesis in the fire salamander, Salamandra salamandra, take place in an intermediate zone of the testis between the cephal immature and the more caudal mature part. Primary spermatocytes in zytogene and pachytene are characterized by synaptonemal complexes, flattened vesicles at the periphery of the cytoplasm and mitochondria with dilated cristae. Mitochondria in primary spermatocytes during meiosis, in secondary spermatocytes and early spermatids are typically arranged beneath the plasmalemma. Secondary spermatocytes are provided with pro-acrosomal granules, nucleolus-like bodies and complexes of annulate lamellae. Cytoplasmic parts with numerous vesicles seem to become extruded from secondary spermatocytes and spermatids. In testicular lobules containing pachytene spermatocytes the normally fibroblast-like follicle cells transform into glandular Sertoli cells. Already after the second meiotic division of germ cells lobule boundary cells show morphological features of steroid hormone secreting cells.