L. Mazzanti

Selective destruction in testes induced by fluoroacetamide

Gli autori descrivono le lesioni del testicolo del ratto osservate nel corso di sperimentazioni con la fluoroacetamide. Tali lesioni consistono in alterazioni regressive interessanti elettivamente la linea seminale.

Histochemical studies of noradrenergic innervation of the liver in untreated and daunomycin-pretreated guinea-pigs.

SummaryThe pattern of noradrenergic innervation of guinea-pig hepatic tissue was examined by using the fluorescence method of Falk et al. (1962). The distribution of monoaminergic nerve fibres in untreated animals was clearly evident at the level of the portal vein, the hepatic artery and the bile duct. The hepatic artery was the most densely innervated. Mast cells and Kupffer cells had no connection with the adrenergic fibres. In daunomycin-pretreated animals, the hepatic cells appeared to be deep red in colour owing to the presence of the antibiotic. Some noradrenergic nervous fibres, never previously described, were unexpectedly distinguishable in the liver parenchyma against the background red colour of daunomycin-pretreated tissue. They appeared to be contiguous to the hepatocytes and were of different shapes: comma-like, V-like, or like a string of pearls. The nature and the functional role of these elements is briefly discussed.

Pharmacological studies of the rabbit and human renal pelvis

SummaryThe responses of the isolated rabbit and human renal pelvis to drugs and to electrical stimulation have been investigated. Regular spontaneous changes in tension occur in the circular smooth muscle, which in the rabbit are synchronous with electrical waves. The responses to electrical stimulation seem to be due to the release of catecholamines from adrenergic nerves. Such nerves have been observed by means of a fluorescence technique. The cholinergic system appears functionally unimportant. The adrenergic responses in human and rabbit seem to be mediated exclusively by α-adrenoceptors.The denervated rabbit organ shows hypersensitivity, mainly to low concentrations of adrenaline. The failure of uptake inhibitors to potentiate the responses to noradrenaline seems in favour of postsynaptic hypersensitivity.

The time course of functional and morphological changes of the guinea-pig colon after “a frigore” denervation of the periarterial sympathetic nerves

SummaryAfter sympathetic denervation of the guinea-pig distal colon the time course and the relationship between morphological and functional changes were studied, by using the fluorescence method and by evaluating the response of longitudinal muscle to periarterial nerve stimulation.The inhibitory response to sympathetic nerve stimulation was completely abolished 48 h after denervation. Tissue catecholamines can no longer be detected in either the intramural vessels or in the intramural plexuses 96 h after denervation, and in no preparation could they be observed again until 24 days after denervation.After 30 days catecholamines stores slowly began to reappear and were completely restored only 100–120 days after denervation. During the whole period of reinnervation the response to periarterial nerve stimulation was lacking.The inhibitory effect could be elicited only 130 days after denervation and before the morphological pattern had been completely restored.

Atrofia del testicolo prodotta dal monofluoroacetato sodico nel ratto albino

The lesions caused by sodium monofluoroacetate on the testis of the albino rat are described. They consist of regressive modifications of the seminiferous tubules which initially cause damage to the intermediate stages and only later to the spermatogonia. The action of sodium monofluoroacetate is similar to that of fluoroacetamide.

Noradrenergic innervation of the heart in untreated and daunomycin-pretreated animals.

SummaryThe innervation of guinea-pig and rat cardiac tissue consists of thin noradrenergic axons running parallel to the myocardial fibres and producing well-developed fluorescent networks which are denser in guinea-pig tissue. Transverse sections of arterial vessels exhibit a marked polar-like disposition of adrenergic nerves, which mainly appear to be concentrated in two opposite areas. Tissue sections from daunomycin-treated animals fluoresced a striking organge-red. This drug-specific fluorescence emanated from all parts of the ventricular tissue, with particular intensity in the nuclei. Neither the density nor the shape of the adrenergic nerves were affected by treatment with the drug. Despite penetration and storage of the antibiotic into the ventricular tissue, cardiotoxicity was not found in the present study.

La Rigenerazione del testicolo atrofico da Fluoroacetamide

Morphological changes of atrophic testis, obtained by treating normal rats with fluoroacetamide, are studied at various times after treatment. The data show that the testicular germinal epithelium is fully regenerated 165 days after treatment.