Knowledge of structural and physiological differences among the prostatic lobes (PL) is the basis for development of experimental studies in traditional laboratory rodents. Although Mongolian gerbil reproductive organs have been increasingly investigated, its prostate structure is far from being properly known, and investigations of this organ focused on the ventral lobe (VL). Thus, the present study provides a thorough morphological description of prostatic complex in the male adult gerbil on the basis of topographic, histological, and ultrastructural analysis and ductal branching. Like other rodents, four pairs of PL were observed. However, in contrast to the rat and mouse, the VL is the least voluminous component and the dorsolateral lobe (DLL) is the most prominent and spatially isolated from remaining PL. The occurrence of a dorsal lobe (DL), hidden between bladder and insertion of seminal vesicles, has not been mentioned in previous reports with Mongolian gerbil. Collagenase digestion followed by microdissection revealed that, except for DL, which has a tubularacinar organization, all PL exhibit tubular organization and variable ductal branching. Distinct histological and ultrastructural features such as secretory epithelium, aspect of luminal secretion and stromal organization are reported for each PL and are confirmed by morphometric and stereological methods. Histological sections showed at least three intralobar segments in VL and DL. Ultrastructural analysis evidenced that, although luminal epithelial cells of PL share typical features of exocrine secretory cells, there are striking lobe phenotypical variations. Both merocrine and apocrine pathways are observed in variable rates in all PL, with the predominance of the former in the DLL and the latter in the CG. The morphological observations presented herein point to distinct structural identities for each PL, which probably reflects specific functional compromise of seminal fluid secretion. These data also point to the gerbil as a good model for investigations concerning the regulation of prostate development and homeostasis, mainly with regard to the dorsal and dorsolateral PL.

The hormonal oscillations that occur during the female reproductive cycle influence the morphophysiology of several organs of the reproductive system. The female prostate is a functional organ sensitive to the action of steroidal hormones, but it is not known whether the hormonal oscillations that occur during the reproductive cycle can alter the biology of this gland. Thus, the present work aims to evaluate the morphofunctional aspects of the female prostate during the gerbil estrous cycle. For this purpose, morphological, morphometric-stereological, serological, and immunocytochemical analyses were carried out. The results of the present study show that the hormonal oscillations that occurred during the estrous cycle altered both the structure and functionality of the gerbil female prostate. These alterations include increased prostatic growth and augmented secretory activity during the proestrus and estrus phases and a gradual decrease of the secretory activity and glandular development in the diestrus I and II phases. These cyclical oscillations appear to be determined by the hormonal peaks of estrogen in diestrus II and by the high levels of progesterone during estrus, since the androgen levels remained constant throughout the estrous cycle.

RESUMO. O presente trabalho objetivou análise macroscópica e histológica do fígado de Leporinus macrocephalus para avaliar a estrutura do tecido hepático. Os peixes provenientes de um pesqueiro da região de Bauru, Estado de São Paulo, foram anestesiados, mortos, e os fígados foram retirados e encaminhados à rotina histológica, com inclusão em paraplast. A macroscopia mostrou um figado de estrutura homogênea, de coloração marron-avermelhada, localizado na região medial do corpo, caudalmente ao coração e posterior às brânquias, apresentando três lóbos de forma piramidal, sendo um central e dois laterais direito e esquerdo. A análise histológica revelou o tecido hepático constituído por cordões duplos de hepatócitos circundados por sinusóides, denominado de "muralha dupla". Revelou, ainda, um sistema biliar disperso pelo parênquima hepático mostrando ductos com epitélio cúbico simples, circundado por fibras musculares e tecido conjuntivo. Células do tecido pancreático exócrino foram observadas, margeando vasos sangüíneos, organizando-se em ácinos apresentando grânulos de zimogênio. Além disso, existem centros melanomacrófagos distribuídos ao longo de todo parênquima, preferencialmente próximos aos vasos sanguíneos, formados por células que acumulam materiais como melanina e lipofucsina, podendo sua presença estar relacionada com o estado nutricional do peixe.

The efficacy of evoked ACh release by intact and newly sprouted terminals in response to partial denervation and expansion of the motor neuron terminal field was studied in mouse soleus muscle after section of the L-5 spinal root. From 2 to 4 d after partial denervation until 90 d later, only 3-7 motor units of the normal 21 remained. Regeneration of the dissected nerve was prevented while the remaining motor units were sprouting. The indirect twitch, which was only 20% of direct twitch tension 2-4 d after nerve section, recovered between 28 and 50 d postoperatively. However, the depression of twitch in low Ca/high Mg solution, which was equal to control 2-3 d postoperatively, was 2-3 times more depressed than control by 50 d and remained so up to 90 d. This indicated persistent reduction of the safety factor in sprouted motor units. Intracellular measurement of quantal content in 0.4 mM Ca, 2.75 mM Mg revealed 2 groups of nerve terminals in partially denervated muscle. The quantal content of the first group was greater than contralateral control at earlier times (28-50 d) and only slightly greater than control later (74 and 90 d). This group consisted of the original undenervated terminals, since it was associated with normal miniature endplate potential (MEPP) frequency and end-plate potential (EPP) latency, and presumably with the class of fibers with normal (zinc iodide osmium-stained) nerve terminal morphology and occasional large myelinated preterminal axons.(ABSTRACT TRUNCATED AT 250 WORDS)