An improved histochemical technique for differentiating adrenaline- and noradrenaline-containing cells.

BACKGROUND: Sevki's histochemical technique allows specific staining of catecholamine-containing cells, yet discrimination between adrenaline-(ADR-) cells and noradrenaline-(NOR-) cells is unreliable, being based on hue differences. METHODS: In this work, histochemical differentiation of ADR- and NOR-cells in rat adrenal medulla was carried out by introducing two modifications to Sevki's technique: 1) employment of aged Giemsa solution, and 2) addition of an alkaline differentiating step. RESULTS: With these changes, ADR-cells stained brown, whereas NOR-cells were deep-green, resulting in a clear-cut differentiation. CONCLUSIONS: The modified technique permits to differentiate ADR- from NOR-cells in the adrenal medulla using only a bright field microscope without any sophisticated equipment. The present procedure is inexpensive and easy to carry out.

Effect of intraperitoneal nitroprusside and adrenergic agonists on food and water intake.

In previous works it was shown that catecholamine-induced hypodipsia is mediated by alpha1-adrenergic receptors while food intake (FI) inhibition supposes also beta-adrenergic participation. We used sodium nitroprusside (N) as a vasodilator, alone or mixed with various adrenergic agonists and measured FI and water intake (WI) in rats either deprived food and water overnight or in postprandial conditions after only 1 hour of deprivation in day time. N injected alone had no effect after overnight deprivation but diminished significantly norepinephrine (NE)-induced inhibition of both intakes, while epinephrine (E) inhibited only FI. In day time, N stimulated 30 min FI by 60% and WI by 84% in male but not in female rats. Isoproterenol (I) stimulated only WI (by 155%), while phenylephrine (P) and E inhibited it by 55%. In the presence of N, I increased WI even more (by 220%) but reduced FI. P + N and E + N increased FI by 41% and 128% as compared with P and E, respectively. Only P-induced inhibition of WI was canceled in presence of N. The results show that N, probably due to nitric oxide production, may induce hyperphagia and hyperdipsia in 1 hour-deprived male rats and also that catecholamine effects on FI and WI are differently modulated by N.

Effect of lipectomy and long-term dexamethasone on visceral fat and metabolic variables in rats.

Intraperitoneal (IP) fat accumulation in humans is a risk factor for a number of diseases. We tried to increase this particular adipose mass in rats by long-term administration of low-dose dexamethasone (Dex) and/or elimination of other fat depots. Male adult Wistar rats were lipectomized (Lip) or sham-operated (Sh). Bilateral lipectomy of retroperitoneal and inguinal fat pads was performed under anesthesia with Na pentobarbital 40 mg/kg supplemented with ether. After 8 days, half the animals of each group received Dex in their drinking water (0.1 microgram/mL) while the other half received water (W), for a total of four groups: Sh-W, Lip-W, Sh-Dex, and Lip-Dex. Body weight (BW) and food and water intake were measured throughout the treatment period. A glucose tolerance test was performed 34 days after starting Dex treatment, and then rats were killed, fat depots were weighed, and plasma and liver were obtained for metabolic determinations. Dex rats ate the same amount of food as W controls, but gained significantly less weight (2.02 +/- 0.18 v 3.82 +/- 0.10 g/d, P < .01). Mean daily W intake was approximately 40 mL/d in all groups, which means that Dex rats ingested approximately 4 micrograms/d Dex. Average glycemic values during the 180-minute glucose tolerance test were as follows: Sh-W, 162 +/- 13; Lip-W, 166 +/- 7; Sh-Dex, 118 +/- 6; and Lip-Dex, 229 +/- 27 mg/dL. These values show that glucose tolerance was improved by Dex treatment alone, but was impaired in Lip-Dex animals. The same trend was evident for the relative weights (percent of BW) of two intact adipose depots: IP and epididymal (EPI) (Sh-W, 2.08 +/- 0.13 and 1.35 +/- 0.11, respectively; Lip-W, 1.67 +/- 0.15 and 1.17 +/- 0.11; Sh-Dex, 1.66 +/- 0.10 and 1.28 +/- 0.07; Lip-Dex, 2.41 +/- 0.11 and 1.53 +/- 0.09). Average glycemia for all rats was significantly correlated with IP (r = .55, P < .01) but not with EPI; moreover it was correlated in the Sh-W control group (r = .81, P < .05), suggesting a normal relation between these variables. Liver triglycerides (LTG), which were elevated in Dex rats, were also correlated with IP (r = .51, P < .02 for all rats and r = .82, P < .05 for Sh-W rats). The results show that long-term administration of low-dose Dex has some different effects in normal versus Lip rats concerning mainly the IP fat depot, the relative mass of which seems to significantly affect glucose tolerance.

[Effect of adrenaline on food consumption and C-fos expression in the central nervous system]. / El efecto de la adrenalina sobre el consumo de alimento y la expresión de C-fos en el sistema nervioso central.

Intraperitoneal (IP) or intraportal epinephrine (E) administration produces strong hypophagia in rats whereas intravenous or intramuscular (IM) injection does not. These results suggest that E acts on liver to control food intake through vagal afferents to the brain. In the present work, immediate-early gene c-fos expression was used as an index of neuronal activity, comparing the respective effects of IP and IM E on food intake and on activation of brain areas that receive vagal information. Male Wistar rats were IP or IM injected with saline or E (100 micrograms/kg). In a first experiment, food intake was measured. In a second experiment, c-fos expression in different brain areas was assessed immunohistochemically. IP E administration reduced food intake by 75% (p < 0.01) whereas IM E had no effect. C-fos expression results showed that those solitary tract nucleus/area postrema regions receiving gastrointestinal and hepatic vagal afferents were specifically activated by IP E administration. These results support the possibility that E decreases food intake through a hepatic action involving vagal sensory neurons. However, higher integration levels of vagal information, such as lateral parabrachial nucleus or paraventricular nucleus, do not seem to be implicated in IP E effect on food intake.

[Ultrastructural identification of human immunodeficiency virus in placenta, embryonic tissue and semen]. / Identificación ultraestructural del virus de la inmunodeficiencia humana en placenta, tejidos embrionarios y semen.

The objective of this paper was to evaluate, ultrastructurally the placental site, placenta, umbilical cord, embryonal tissues, and semen from 10 patients (5 females and 5 males), seropositive for the Human Immunodeficiency Virus. The tissue samples were processed by the routine techniques for electronic microscopy, and were examined with a Zeiss EM-10C Electronic, transmission microscope. Among the decidual cells of the placental site, macrophages were found, which contained vacuoles with particles similar to a virus, inside. Similar to virus, particles were found among microvilli of syncytiotrophoblast; it presented with a thick basal membrane and with calcifications. Hyperplasia of Hofbauer cells was seen, although there were not viral particles inside. In the membrane of fetal erythrocytes there particles, electron dense, possibly from viral origin. Viral particles were identified in the nuclei of endothelial cells of the brain and lung. In the semen budding areas were seen in immature spermatozoon; and similar particles were seen y spermatozoa, probable desquamation cells, and in seminal protein, in free form. It is concluded that the HIV may be transmitted via transplacental in very early stages of gestation. The hyperplasia of Hofbauer cells can be a response of local defense. And finally, the presence of viral particles in the different components of semen favor its transmission by sexual contact.

[The morphological aspects of the placenta, embryonic tissues and semen in human immunodeficiency virus infections]. / Aspectos morfológicos de placenta, tejidos embrionarios y semen en infecciones por virus de inmunodeficiencia humana.

Tissue samples from a therapeutic curettage performed in a woman with acquired immunodeficiency syndrome and a semen sample of the husband were studied with the electron microscope. The samples were processed according to routine technique for electron microscopy. Calcifications, basement membrane thickening and hyperplasia of Hofbauer cells were seen in the placenta villi. Electron-dense particles of unknown nature, probably of viral origin, were found on the fetal red blood cell membranes, virus-like particles were identified in the endothelial cell nucleus of the brain and lung. Retrovirus-like particles were found in the protein of the seminal plasma. These results suggest that the retrovirus pass through the placenta during early pregnancy.