Archivio di scienze biologiche最新文献_第2页

Histological changes in Xenopus laevis Daudin adult specimens kept under dry conditions, then moved back to their natural aquatic environment. II. Skin, kidney and interrenal tissue. 在干燥条件下保存的非洲爪蟾成虫标本的组织学变化，然后移回其自然水生环境。2皮肤、肾脏和肾间组织。

Archivio di scienze biologiche Pub Date : 1978-01-01

E Campantico, A Guardabassi, L Torasso

{"title":"Histological changes in Xenopus laevis Daudin adult specimens kept under dry conditions, then moved back to their natural aquatic environment. II. Skin, kidney and interrenal tissue.","authors":"E Campantico, A Guardabassi, L Torasso","doi":"","DOIUrl":"","url":null,"abstract":"Some cytological and histochemical characteristics of skin, the kidney and interrenal tissue were studied in Xenopus laevis adult specimens (1) kept in their natural aquatic environment; (2) gradually exposed to dry conditions under which they were kept one week; and (3) returned from the dry environment to water for 24 hr or a week. In the skin, the most relevant changes are those exhibited by epidermal \"flask\" cells. These cells are generally rather lean, tall and PAS-positive in \"dry\" animals and in those 24 hr after replacement in water, whereas in animals placed back in water for a week \"flask\" cells are often large and faintly stainable. In \"dry\" animals, the skin mucous glands look more emptied of secretion granules than in control animals kept in water or in \"dry\" specimens returned to water. Difference in the epidermis thickness or in its histochemically evidenced alkaline phosphatase activity were not observed between different groups. In the kidney a clearcut difference between animal groups was found in the glycogen content of the proximal convoluted tubules of the nephron. Glycogen level is very low in \"dry\" animals. These variations are tentatively ascribed to different degrees of electrolyte resorption. In the interrenal cells, the sudanophil material is scanty in \"dry\" animals, while it is much more abundant in those returned to water for 24 hr. Similar, though less pronounced, effects had been obtained in previous experiments of ours, in which some of the animals were kept out of water on moist moss, that is under less severe conditions of water deficiency than in the present experiments.","PeriodicalId":8354,"journal":{"name":"Archivio di scienze biologiche","volume":"62 1-4","pages":"63-76"},"PeriodicalIF":0.0,"publicationDate":"1978-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11530956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Dopamine, catecholamine receptors, and neurohumoral regulation of renal function]. [多巴胺、儿茶酚胺受体和肾功能的神经体液调节]。

Archivio di scienze biologiche Pub Date : 1978-01-01

G C Agnoli, M Cacciari, A Cariani, C Garutti, P Lenzi

{"title":"[Dopamine, catecholamine receptors, and neurohumoral regulation of renal function].","authors":"G C Agnoli, M Cacciari, A Cariani, C Garutti, P Lenzi","doi":"","DOIUrl":"","url":null,"abstract":"Were studied in healthy human subjects under conditions of hydro-saline retention the intrarenal mechanism underlying the hydronatriuretic effect of Dopamine (DA) and the changes in DA renal effects induced by Sulpiride (S). DA was infused i.v. in a subpressor dose (0,1 microgram/kg . min) during induced hypotonic polyuria. In each experiment four clearance periods of 15 min were performed; DA was administered during the second and third clearance periods. The glomerular filtration rate and renal effective plasma flow were estimated as endogenous creatinine and PAH clearances, respectively. Tubular sodium and potassium reabsorptions were also determined. 1) In the state of hydro-saline retention, renal arteriolar (mainly preglomerular) vasodilation was produced by DA. Moreover, both sodium isosmotic reabsorption as a percentage of sodium filtered load and sodium anisosmotic reabsorption as a percentage of sodium distal load were inhibited. These tubular inhibitions were found to be correlated with the haemodynamic effects of DA. 2) Sulpiride treatment (4,4 mg/kg . day given orally for two days prior to the experiment and 100 mg i.m. 40 min before DA infusion) caused (a) an increase in the hydro-natriuretic response to hydration during control clearance and (b) a decrease in DA haemodynamic effects. An interpretation is proposed accounting for these DA effects as well as for dependence of DA renal effects on the extracellular fluid volume.","PeriodicalId":8354,"journal":{"name":"Archivio di scienze biologiche","volume":"62 1-4","pages":"83-129"},"PeriodicalIF":0.0,"publicationDate":"1978-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11759307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The effects of noradrenaline, applied by microelectrophoresis on different cells of the rabbit's atrial pacemaker. 微电泳法观察去甲肾上腺素对兔心房起搏器不同细胞的影响。

Archivio di scienze biologiche Pub Date : 1978-01-01

G L Avanzino, R Ermirio

{"title":"The effects of noradrenaline, applied by microelectrophoresis on different cells of the rabbit's atrial pacemaker.","authors":"G L Avanzino, R Ermirio","doi":"","DOIUrl":"","url":null,"abstract":"Noradrenaline has been applied by microelectrophoresis to a small portion of the atrial pacemaker area in the rabbit's heart in order to study the local effects of this chemical transmitter separately from the ones deriving from other parts of the pacemaker area. In a first group of cells, whose action potential and location assimilate them to true pacemaker cells, noradrenaline caused a reduction in cycle length and an increase in the steepness of slow diastolic depolarization. In a second group of cells similar to latent pacemaker cells, noradrenaline caused no change in cycle length, the outstanding effect being an increase in the steepness of the slow diastolic depolarization which afterwards changed into a subthreshold oscillation. A third type of cells showed intermediate characteristics between the two previous groups. These results suggest that: a) the chronotropic effect of noradrenaline on the heart atrial pacemaker seems to be due to changes in the steepness of slow diastolic depolarization which can assume, in some instances, the shape of subthreshold oscillations; the effects on the other parameters in our preparation seem to be either less constant or less significant; b) the different effects which are obtained on various kinds of cells seem to be the result of a different degree of sensitivity to noradrenaline and to the more or less premature activation of mechanisms antagonizing the action of noradrenaline. The results are discussed on the basis of a model of spontaneous atrial pacemaking which has been recently proposed.","PeriodicalId":8354,"journal":{"name":"Archivio di scienze biologiche","volume":"62 1-4","pages":"177-92"},"PeriodicalIF":0.0,"publicationDate":"1978-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11759491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Histological changes in Xenopus laevis Daudin specimens kept under dry conditions, then moved back to their natural aquatic environment. I. Pituitary, thyroid and testis. 在干燥条件下保存的非洲爪蟾标本的组织学变化，然后移回其自然水生环境。1、垂体、甲状腺和睾丸。

Archivio di scienze biologiche Pub Date : 1978-01-01

A Guardabassi, E Campantico, I Panebianco

{"title":"Histological changes in Xenopus laevis Daudin specimens kept under dry conditions, then moved back to their natural aquatic environment. I. Pituitary, thyroid and testis.","authors":"A Guardabassi, E Campantico, I Panebianco","doi":"","DOIUrl":"","url":null,"abstract":"The histofunctional picture of the hypophysis, thyroid and testis was studied in Xenopus laevis specimens 1) kept in their natural aquatic environment; 2) gradually exposed to dehydration conditions under which they were kept one week; and 3) returned from the dry environment to water for 24 hr or 7 days. Of particular interest are the changes displayed in the hypophysis by type II acidophils, i.e. presumably prolactin producing cells. In the pituitary of \"dry\" animals and of those 24 hr after their replacement in water these cells appear numerous, large-sized and heavily stained whereas they are small and slightly stainable in the pituitary of control animals or of \"dry\" ones 7 days after their replacement in water. On the basis of these results it is surmised that prolactin is continuously synthesized and released into the circulation in Xenopus specimens kept or replaced in water, thereby contributing to the animals adaptation to the aquatic environment, whereas in those kept under waterless condition prolactin synthesis is not discontinued, but its release into the bloodstream declines or is abolished. In the testis of the animals kept in dry conditions or 24 hr after replacement in water, the germ cells do not seem to have undergone substantial changes, while the sudanophilic material, which can be detected in interstitial tissues in the animals kept in water, is lacking. In all groups the thyroid histofunctional pattern suggests an intense activity, particularly in control animals or in \"dry\" specimens 7 days after replacement into water.","PeriodicalId":8354,"journal":{"name":"Archivio di scienze biologiche","volume":"62 1-4","pages":"51-61"},"PeriodicalIF":0.0,"publicationDate":"1978-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11759306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Membrane potential: which formulae do hold? 膜电位:哪些公式适用?

Archivio di scienze biologiche Pub Date : 1978-01-01

P Lenzi

引用次数: 0

The brain of the guinea pig in stereotaxic coordinates. 立体坐标下的豚鼠大脑。