Atrial natriuretic peptide secretion during development of the rat supraoptic nucleus.

Since a relationship between atrial natriuretic peptide and oxytocin was recently demonstrated in the heart (Gutkowska et al., 1997), the aim of this study was to determine whether a relationship between the two peptides is present also in the rat hypothalamus. For this purpose, we measured ANP-ontogeny in the rat hypothalamus immunohistochemically and compared it with oxytocin-ontogeny which we previously studied. The results showed that the ANP-peptide and mRNA-ANP start at the 18th day of the fetal life. Our earlier data for oxytocin in the rat hypothalamus showed that only mRNA-oxytocin appeared the 18th day of foetal life (Farina Lipari et al., 2001); thus, at the 18th day of foetal life, mRNA-ANP, ANP-peptide and mRNA-oxytocin are present. We conclude that in the hypothalamus, differently from that in the heart, ANP might play a role on the synthesis of the oxytocin since ANP and its mRNA appear earlier than oxytocin.

The hemolysin-producer coelomocytes in Holothuria polii.

Using sodium metrizoate discontinuous gradients, two hemolysin-producer amebocyte populations have been separated from total circulating Holothuria polii coelomocytes. The amebocytes of population 1 are responsible for the production of the calcium-dependent and temperature-labile hemolysin, whereas those of population 2 produce the calcium-independent and temperature-stable one. The intracytoplasmic hemolysins were evidenced also by immunofluorescence. Petaloid and filipodial amebocytes were the only positive cell types.

Immunohistochemical localization of atrial natriuretic factor (ANF) in the excretory system of the rabbit parotid gland.

The immunohistochemical localization of atrial natriuretic factor (ANF) in the rabbit parotid gland was performed using an antibody against rabbit ANF and avidin-biotin or streptoavidin as detector. Results showed positivity in cuboidal and columnar cells of intralobular ducts and in basal cells of extralobular and main excretory duct. These data support the hypothesis that ANF produced by intralobular ducts could act through a paracrine mechanism; ANF produced by extralobular and main ducts may play a role in the regulation of salivary composition.

Presence of atrial natriuretic factor in normal and hyperplastic human prostate and its relationship with oxytocin localisation.

In this work, we showed the presence of atrial natriuretic factor (ANF) in human prostate and compared its localisation in normal and hyperplastic conditions. ANF was localised in epithelial and stromal cells, being increased in hyperplasia, mainly in the stromal component. Moreover, we compared ANF and oxytocin positivity in the same glands, focusing on the possible relationship between the paracrine effects of these two hormones.

A contribution to knowledge of the compartments and the fascial and septal formations of the popliteal fossa in the human fetus and the adult.

A contribution to knowledge of the compartments and the fascial and septal formations of the popliteal fossa in the human fetus and the adult. A study was made in human fetuses from the 3rd month onwards, newborn and the adult of the fascial and septal formations and the compartments of the popliteal fossa. Observations of serial sections of the knee of human fetuses, of macroscopic preparations of the knee of newborns and of ultrasound images of the popliteal fossa in adults showed that: the fascial formation covering the popliteal fossa consists of the popliteal fascia and the superficial fascia. The bud of the popliteal fascia is observable in the 3-month fetus as a layer of thin fibrillar connective tissue which is thicker in the tracts between the muscle buds. At birth the popliteal fascia is clearly a separate anatomical entity of continuous laminar structure which is thicker in the tracts between the muscles and thinner where it covers them. The superficial fascia becomes evident in fetuses at a later stage (6th month) in the form of a thin lamina in the frontal plane which at birth is well defined and observable as a thin continuous line deep below the subcutaneous layer. The septal formation consists of four septa: two in the sagittal plane (lateral and medial) and two in the frontal plane (lateral and medial). The bud of these septa appears in 4-month fetuses after the appearance of the popliteal fascia. They branch off from the thicker connective areas between the muscles buds as connective prolongations which later assume a laminar aspect and eventually become compact and form septa. In at-term fetuses and newborns these septal formations are clearly recognizable as antomical entities, which branch off from the deep surface of the thicker tracts of the popliteal fascia and are inserted into the femur. The relationships and connections with the muscular groups are also clearly visible. The organization and demarcation of the compartments, which is already delineated in the 6-month fetus, seems to be completed at birth, considering the presence of the superficial fascia, the popliteal fascia and the septa. It is possible to distinguish a superficial compartment between the popliteal and the superficial fascia an a deep compartment between the frontal septa, the skeletal plane and the popliteal fascia. This deep compartment is clearly subdivided by the two sagittal septa into three sectors (medial, intermediate and lateral). The medial and lateral sectors contain muscles, while the intermediate compartment contains the vasculonervous bundle and the popliteal adipose body.

Localization of the atrial natriuretic factor in the human inferior turbinates. An immunohistochemical study.

In man, the architecture of the turbinates is able to modify some of the physiochemical characteristics of the air inhaled. These modifications depend on the nervous system and on the action of neurotransmitters such as vasoactive intestinal peptide. Substance P, calcitonin gene-related peptide and other neuropeptides. As atrial natriuretic factor has been detected in the trachea and lung, the present immunohistochemical study was carried out to establish the presence and localisation of the atrial natriuretic factor on the inferior turbinates of the human being. The findings show atrial natriuretic factor to be present in the serous epithelial cells and in some cells of the tonaca propria near the sinusoids and the arteriovenous shunts and the acinar cells of the glands. Atrial natriuretic factor, therefore, could play a part in the stratification of mucus on the luminal surface and also regulate the blood flow of the capillaries, modifying, in this way, the physiochemical features of the air inhaled.

Immunohistochemical and biomolecular identification of orphanin FQ, eNOS, atrial natriuretic factor and oxytocin in rat seminal vesicles.

In previous studies performed on rodents, we detected the presence of adreno-cholinergic and peptidergic innervation in seminal vesicles and other organs of the male genital system, such as prostate and deferent duct, in which we also investigated the expression of NOS and NADPH-diaphorase. During this project, we focused our attention on the expression of some peptides involved in local control of smooth muscle relaxation, contractility, vasodilatation and control of blood flow in rat seminal vesicles. We investigated, through immunohistochemistry and RT-PCR, the presence of four peptides: orphanin, eNOS, ANF and oxytocin. Immunohistochemistry was used to detect the presence of the proteins, whereas RT-PCR analysis confirmed gene expression of orphanin, eNOS and ANF, but not oxytocin. In our opinion, orphanin, eNOS and ANF could have paracrine effects regulating the function of seminal vesicles, whereas oxytocin, which may reach this anatomical district through the blood flow, may have a hormonal action. This is a pilot study that, with further investigation, may allow to better clarify the role of these molecules in the control of seminal vesicle tissues' homeostasis.

Immunohistochemical research on vasopressin in the accessory hypothalamic nuclei.

Immunohistochemical studies were performed using antivasopressin on the neurons and the accessory nuclei of the anterior hypothalamic region of rat. Accessory neurons had a positive vasopressin reaction which was similar to that already found in the supraoptic and paraventricular nuclei. The accessory neurons should therefore be considered part of the neurosecretory magnocellular system because of their morphological aspect, and because of their secretory activity.

[Transmission electron microscopy observations of a homologous bone graft preserved at -196 degrees C]. / Osservazioni al MET di un innesto di osso omologo conservato a -196 gradi C.

The authors have studied the ultrastructural modifications after one year of a homologous bone grafting stored for 8 days in nitrogen liquid at -196 degrees C. It was observed that the osteocytes showed nuclear and cytoplasmic degenerations; the empty lacunae showed precipitates of mineralized matrix. In comparison with a bone autografting a homologous bone grafting lost the ability of bone synthesis.

Immunohistochemical research on oxytocin in the hypothalamic accessory nuclei.

Immunohistochemical research on the monoclonal antibody, anti-oxytocin, was carried out on hypothalamic accessory nuclei. The nuclei and the accessory neurons were strongly positive in much the same way as the supraoptic and paraventricular nuclei. These results indicate that the accessory nuclei are able to synthesize the neurohormone oxytocin. Based on the present research and on preceding papers, it is possible to affirm that the accessory nuclei synthesize both oxytocin and vasopressin. Therefore the accessory nuclei must be considered an integral part of the magnocellular hypothalamic neurosecretory system.

Immunohistochemical research on the atrial natriuretic factor (ANF) in rat atrioventricular valves.

Immunohistochemical research on atrioventricular valves in normotensive rats revealed that valvular myocardiocytes are the seat of synthesis of the atrial natriuretic factor (ANF). The endocardial cells that border the atrial and ventricular surfaces also had granules which were positive for ANF. The ANF which is also synthesized in the valvular myocardiocytes moved towards the cardiac cavity and crossed the endocardial cells in the more distal areas of the valvular edge. At the same time, the ANF was routed into the blood vessels in the areas close to implantation.