Pretreatment with bendazac attenuates retinal damage induced by intense light in rats.

Bendazac is a drug which protects proteins from denaturation induced by different agents. It is also effective in protecting rabbits from X-ray-induced cataract. This study deals with the effects of bendazac on the intense light-induced retinal damage in rats. Four groups of animals received orally 0, 50, 100 or 200 mg/kg of bendazac L-lysine salt three times a day for 3 days and once the fourth day, before 1 h exposure to intense-green filtered light. Fourteen days after housing in a dark room, the rats were sacrificed and the retinae were examined by light microscopy. Retinal damage was graded according to a score severity from 0 to 5. The mean score for control animals was 2.23, whereas a dose-related and statistically significant reduction of retinal damage was detected in bendazac treated rats, i.e. 1.72, 1.54 and 1.40. A protective activity in the distribution of the severity score, i.e. a higher incidence of no damaged retinae and a lower frequency in the most severely affected ones, was also observed in treated versus control rats. These results suggest a potential therapeutic value of bendazac in the treatment of those conditions, such as retinitis pigmentosa and senile macular degeneration, in which the light exposure plays a role as a co-factor.

Antispermatogenic effects of tolnidamine in langur (Presbytis entellus).

Tolnidamine (50 mg/kg body weight; twice a week; oral) was administered for 90 days to adult male langur monkeys (Presbytis entellus entellus Dufresne) to assess its contraceptive potential. Semen weight, volume, seminal fluid volume, colour, pH and libido remained unchanged. Sperm motility, vitality and morphology were impaired with the advancement of treatment. Sperm density reduced to severe oligospermia following 75-90 days of treatment. Increased number of immature germ cells were also noticed. Resumption of changes to pretreatment range was observed following 90 days of cessation of treatment. However, sperm density remained low all through the recovery period of 150 days. Seminal fructose, ACP, LDH and citric acid concentrations did not change markedly. A significant depletion in GPC and magnesium levels was recorded during treatment and early recovery periods. Alterations in germ cells and Sertoli cells were also observed. A progressive but reversible rise in serum creatinine was evident. Other clinical parameters and body weight response revealed no drug-related alterations. In conclusion, tolnidamine medication induced irreversible inhibition of spermatogenesis.

Lonidamine: a non-mutagenic antitumor agent.

Lonidiamine is a novel indazole-carboxylic acid with antitumour properties; it has been studied for potential mutagenicity in a comprehensive battery of tests. In assays for the induction of gene mutations in prokaryotes (Ames test) and eukaryotes (induction of HPRT mutations in CHO cells), negative results were obtained. There was no evidence of the induction of chromosomal damage in cultured mammalian cells in vitro. No mutagenic activity was observed in tests for chromosomal damage in vivo, in somatic cells (micronucleus test) or in germinal cells (dominant lethal test). These negative results are consistent with observations indicating that lonidamine affects cellular energy processes, rather than the mechanisms of cell division. The lack of mutagenic properties suggests that lonidamine may present significant advantages in treatment of some tumours, offering a reduced risk of resistant clones, secondary cancer and heritable genetic damage.

Postnatal development of epididymis and ductus deferens in the rat. A correlation between the ultrastructure of the epithelium and tubule wall, and the fluorescence-microscopic distribution of actin, myosin, fibronectin, and basement membrane.

The postnatal maturation of regions of the epididymis and intragonadal segment of the deferens duct was studied in the rat by light- and transmission electron microscopy. Maturation of the genital duct starts in the distal cauda epididymidis and ductus deferens after one week of life, and one week later, in the more cranial segments of the epididymis. Epithelial principal cells and peritubular contractile cells are structurally mature 35 days after birth. The synchronous changes of these cells indicate that the same factors control their postnatal maturation. The epithelial principal cells obtain an endocytotic apparatus and long stereocilia, whereas peritubular cells acquire contractile features. These changes are associated with a progressive increase in the immunoreaction for smooth muscle actin in both cell types. Smooth muscle myosin is detected in the apical region of the epithelial cells and the peritubular cell cytoplasm by day one of postnatal development. The differentiation of contractile cells in the wall is accompanied by progressive organization of the pericellular matrix into a continuous basement membrane. Although fibronectin is visible at birth, it is gradually removed from the tubule wall.

Effects of respiratory treatment with N-hexane on rat testis morphology. I. A light microscopic study.

Testicular damage was induced in rats by respiratory treatment with n-hexane at a concentration of 5000 ppm. The earliest lesions were observed immediately after 24 hr of continuous treatment, and involved primary spermatocytes from the leptotene to the middle pachitene stages and spermatids at late stages of maturation; at the same time numerous exfoliated, injured germ cells reached the epididymis. After the 24-hr treatment was suspended, damage to the seminiferous epithelium increased for the first 7 days, while the epididymis showed also focal infiltration by inflammatory cells; recovery was completed from Days 14 to 30. Intermittent treatment (16 hr/day, 6 days/week) at the same concentration of 5000 ppm for up to 6 weeks induced progressive increases in testicular and epididymal lesions, which, after 5 weeks (when most animals began to show clinical symptoms of polyneuropathy), reached aplasia of the germinal epithelium involving also the spermatogonia. Recovery from clinical symptoms was not paralleled by a regression of testicular pathology. On the contrary, after interruption of the treatment, the testicular lesions became increasingly severe, up to complete atrophy of the seminiferous tubules, suggesting an irreversible sterility of the treated animals. Pair-fed controls did not show histological alterations of the testis or epididymis.

Review of pharmacological data on benzydamine.

Pharmacological results are reviewed supporting the use of benzydamine in so-called "primary inflammations" rather than in rheumatic diseases. In experimental studies, benzydamine shares with aspirin-like drugs their activity in acute inflammatory responses but not in Freund's adjuvant arthritis. The efficacy of benzydamine is mainly manifested against phenomena such as pain and oedema which depend on local mechanisms in the inflammatory focus. Other manifestations such as hyperthermia which are indicative of systemic functional involvement, are poorly affected by the drug. Benzydamine also lacks some of the typical side-effects of aspirin-like drugs which are thought to reflect their generalized activity. Finally topical application increases the analgesic and antiinflammatory activities of benzydamine much more than those of other antiinflammatory drugs. The data reported demonstrate that benzydamine specifically acts on the local mechanisms of inflammation. In order to explain this feature the chemical, pharmacokinetic and biochemical properties of benzydamine are discussed.

A comparative study of acute toxicity of drugs used during anticancer therapy in healthy and tumor-bearing mice.

A comparative study was performed, in healthy and Ehrlich ascites bearing mice, to ascertain if the acute toxicity of drugs can change in disease conditions. Adriamycin, cis-platinum, cyclophosphamide, 5-fluorouracil, vinblastine, morphine and cefoxitin were administered intravenously; prochlorperazine and acetylsalicylic acid were given orally, and dexamethasone and lonidamine were given by both routes. With the exception of morphine, the LD50's significantly decreased in tumor bearing animals. The highest potency ratios (about 4-6) were observed with prochlorperazine and cyclophosphamide and the lowest (1.3-1.4) with lonidamine given intravenously, adriamycin and acetylsalicylic acid. These results confirm that the toxic response may be strongly influenced by pathological states.

Ultrastructural and immunohistochemical studies of rat epididymis.

The anatomical distribution of smooth muscle actin, myosin, fibronectin and basement membrane has been investigated immunohistochemically, using the indirect immunofluorescence technique, in the rat epididymis. The findings were correlated with the ultrastructural organization of the organ. Actin was found to be distributed in the stereociliary region of the epithelial principal cells and in the terminal web region. Actin was also visible along the base of the epithelium. Myosin was detected in the terminal web and in the terminal bar regions of the epithelium. The contractile cells showed a strong stain for both proteins. Basement membrane immunoreactivity was distributed along the epithelial basement membrane and around the contractile cells of the wall. In the cauda, between the epithelium and the contractile cell layers, the lamina propria, containing blood vessels and a thin layer of cells, was negative for all antigens investigated. Fibronectin showed a granular distribution around the contractile cells, mainly in the cauda. The ultrastructural study showed only thin (5-6 nm in diameter) filaments in the stereocilia and terminal web region. Thin filaments were also visible in the cytoplasm of the basal cells, thus suggesting a contractile function of this cell type. The heterogeneous appearance of the contractile cells of the wall seemed to support the different contractile pattern of the epididymal regions: caput, corpus and cauda. The cells present in the lamina propria showed cytoplasmic vesicles with dark granules resembling the "A" cell granules of the endocrine pancreas and gut mucosa cells.

The embryotoxicity of a new class of antispermatogenic agents: the 3-indazole-carboxylic acids.

The effects of two antispermatogenic 3-indazole-carboxylic acids on pregnancy in the rat have been studied. AF 1312/TS (1-(4-chlorobenzyl)-1H-indazole-3-carboxylic acid) when administered from day 6 to day 15 of pregnancy produced embryolethality with an LD50 of 145 mg/kg. The more potent antispermatogenic lonidamine was 7.25 times more effective, with an LD50 of 20 mg/kg. No significant teratogenicity was exerted by AF 1312/TS, whilst lonidamine was slightly effective only at embryolethal doses. The latter was also effective after a single administration on day 9, with an embryonal LD50 of 25 mg/kg, whereas the teratogenic effect was greatest on day 10. The similarity of the embryonal LD50 after single or repeated administrations suggests an interference with a specific epigenetic crisis.

Morphological, histochemical and biochemical studies on germ cell mitochondria of normal rats.

Morphological changes in rat germ cell mitochondria are described. In diplotene and secondary spermatocytes and in the spermatids of the Golgi, cap and acrosomal phases, the mitochondria take on a rounded appearance with the inner space containing the matrix flattened against the outer membrane and the intracristal spaces considerably swollen ("condensed" mitochondria). Functional studies on "condensed" mitochondria isolated from the germ cells of normal rats have been performed. The following parameters have been evaluated: ADP/O ratio, respiratory control ratio (RCR) and ADP affinity. The ADP/O values found in the presence of various substrates are in agreement with the theoretical figures. The RCR is remarkably high. Moreover, the ADP affinity of these mitochondria is very high, as demonstrated by the low values of the "apparent Km". These biochemical findings, which demonstrate a high oxidative capacity coupled with a marked phosphorylation, suggest that the "condensed" appearance of germ cell mitochondria is the expression of an active functional state.

Comparative cardiovascular toxicity of trazodone and imipramine in the rat.

Several authors have associated the cardiotoxicity of the tricyclic antidepressants with their capacity to potentiate the response to catecholamines. Trazodone is a psychotropic drug with a clinically proven antidepressant activity. It differes from the tricyclic antidepressants under several aspects (chemistry, pharmacology, mode and mechanism of action, etc.), including interactions with catecholamines. Contrary to the tricyclic antidepressants, it does not potentiate the response to catecholamines, but, instead, has an adrenolytic activity. We therefore decided to compare the cardiotoxicity of trazodone and of a tricyclic antidepressant, i.e. imipramine in the rat. The experiments were conducted on anaesthetized Long Evans rats, the drugs being administered by i.v. infusion until cardiac arrest occurred; ECG (lead II) and blood pressure (BP) were recorded at the same time. The primary effect of trazodone was its hypotensive action. ECG changes, consisting of a lengthening of the PR interval, were observed only when there was a marked drop in BP. The primary effect of imipramine, instead, consisted of disturbances in cardiac conduction. It is concluded that trazodone and imipramine produce different cardiovascular effects.