A significant part of the morbidity in elderly men involves pelvic organs and their autonomic neural regulation. Environmental stimuli also impair the structure and function of pelvic organs. One of these factors is citral, a widely-used cosmetic fragrance constituent, which causes severe prostatic hyperplasia in rats. In this study, we assessed the effect of topical administration of citral (30 days) on the morphology of pelvic ganglia (PG) in young adult and old Wistar rats. Neuronal vacuolar degeneration with preserved nuclei of PG neurons was observed in untreated senescent, but not young rats. Citral significantly increased the rate of vacuolated neurons in old rats (from 3 to 14%), but only slightly in young ones (from 0 to 0.5-0.3%). Similar lesions were not found in inferior cervical or celiac ganglia, in either group. This shows that environmental stimuli enhance age-related processes of vacuolar neuronal degeneration in PG, and may contribute to the dysfunction of pelvic organs in the elderly.

The vasoactive effect of a fragrance compound, citral, on rat ventral prostate is presented. A combined method of Indian-ink perfusion and postfixation transparency was used. One single dose of citral applied on the back skin of the rat induced an immediate triple response-like effect on the prostatic vascular bed. A slight vasodilatation appeared already after 2 1/2 min, followed by a marked vasoconstriction process after 5-min postcitral administration. Toward the period of 10 min, a second vasodilatation process was noted which persisted for the following 24 hr of observation. This study has demonstrated that changes in the microvascularization of the rat prostate can be estimated by counting the number of carbon-stained blood vessels. The results obtained by this technique are closely related with the findings in the vascular network profile of the macroangiographic observations. The mechanism of action of citral on the microvascularization of the rat ventral prostate is yet unknown. Based on the present findings, we suggest that the neoplastic capacity of citral upon the prostatic epithelia is activated via a nonspecific inflammatory reaction modulated either by local release of neurotransmitters or throughout a direct effect of citral on the endothelial cells.

A case of a spontaneous intratubular spermatic seminoma is described in a 98-wk-old Fischer-344 (F-344) rat. The differential diagnosis of spermatic seminoma from the other morphological forms of the tumor was based on the recognition of 3 cell types. The tumor cells were positive for S-100 antigen and cytokeratin. To the best of our knowledge, this is the second case of a seminoma reported in an F-344 rat and the first dealing with electron microscopic and immunohistochemical features of this tumor.

Vascular distribution of small blood vessels and capillaries using India ink angiography was studied in normal rat prostate from puberty up to full sexual maturation. The study included both macroscopic observation of the lobular vascular irrigation and the histological assessment of the periacinar capillary network. The topographical distribution of the main prostate branches was found to be different among the rat prostate lobes. The ventral lobe seems to be better irrigated than the dorsal one. The former being supplied by two parallel vascular systems, one irrigating the median two-thirds of the ventral lobe, whereas the remaining external one-third was found to be conjointly irrigated from the pericapsular branches of the fat pads. The blood vessels of the dorsal and lateral lobes emerged radially from a periurethral circle, with the dorsal branches ending blindly in the connective tissue of the pelvic cavity, whereas the lateral prostate was also conjointly irrigated by a dual vascularization from the pericapsular fat pad and the periurethral circle branch. The histological study revealed quantitative differences between the periacinar capillaries of both ventral and dorsal lobes. The capillary density was found to be age dependent and directly proportional to the acinar size. Small acini were less well irrigated by capillaries than were the larger ones.The number of capillaries per acinar area increased progressively toward the maturation (day 90); thereafter, their number remained constant. Both prostate lobes showed identical patterns. The heterogeneous vascular networks among the rat prostatic lobes might offer an additional clue for their distinctive morphophysiological characteristics, which most probably play a role in various pathogenetic processes.

The microscopic features of a spontaneous uterine granular cell tumour in a Fischer 344 rat are described. The location of the tumour is novel for the rat. The neoplasm is characterized by the presence of cells with cytoplasmic granules which were PAS positive and diastase resistant. Electron microscopy and immunohistochemistry results are presented and the origin of the tumour is discussed.

This study investigated a technique for the quantification of hemosiderin layed down in the spleen. The model used was the rat to which the urea-based herbicide chlortoluran was fed for 90 days. There was good correlation between hematological, biochemical, histological and image analytical techniques when splenic hemosiderosis was of a moderate to severe degree. Where hemosiderosis was of a slight nature, only the technique of image analysis was able to detect the on-going changes.