Foetal haemopoiesis during the hepatic period

نویسنده

  • C. E. BOZZINI
چکیده

Serial sections of mouse foetal liver, during the 9th and 16th days of gestation, were studied. The erythropoietic process starts in the central area of the growing hepatic lobes, and subsequently spreads towards the periphery. Each lobe passes successively through an undifferentiated, proliferating and differentiating period, but does not proliferate and differentiate in a homogeneously synchronized way, since the onset of both histogenesis and erythropoiesis is delayed at the periphery, when compared with the central area. As a consequence, in sections it is possible to find three different zones, namely: marginal, which is the most undifferentiated; intermediate (transitional); and a central area, which is the most mature, since it is the first site where erythropoiesis arises. These zones are distinguishable not only by their cell distribution, but also by the biological behaviour of their elements, specially in the transitional areas between undifferentiated and proliferating zones. The hepatic lobes do not start their organogenesis at the same time; but those of them in which histogenesis is delayed, repeat courses of development similar to those previously organized. The first interstitial erythropoiesis appears in the central area, after the development of an organized network of sinuses, and in close relation to vascular channels. Dynamic images of immature blood cells, between interstitial and vascular spaces, suggesting passage through the endothelium, are often seen. These steps are followed, in a concentric form and spreading towards the periphery, by each hepatic lobe.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Growth and Function in the Foetal Liver

INTRODUCTION MANY investigators have demonstrated the decline which takes place in the relative weight of the liver during the development of the mammalian foetus; Carlyle (1945) and Wallace (1945) in the sheep, Jackson (1909) in man, Lowrey (1911) in the pig, Williamson (1948) and Addis & Gray (1950) in the rat, Latimer & Corder (1948) in the dog, and Latimer (1948) in the cat. The present wor...

متن کامل

Haemopoiesis and Siderosis in the Foetus

In 1941 Gilmour described haemopoiesis in the foetus and newly born infant. His investigations were prinarily qualitative and were undertaken as a preliminary to the study of erythroblastosis foetalis (1944). The investigations to be reported here were essentially quantitative. Their ultimate objective was the comparison of the amounts of haemopoietic tissue and stainable free iron in the organ...

متن کامل

Foetal haemopoiesis during the hepatic period. II. Topographic histology.

Serial sections of mouse foetal liver, during the 9th and 16th days of gestation, were studied. The erythropoietic process starts in the central area of the growing hepatic lobes, and subsequently spreads towards the periphery. Each lobe passes successfully through an undifferentiated, proliferating and differentiating period, but does not proliferate and differentiate in a homogeneously synchr...

متن کامل

Regulation of onset of development of UDP-glucuronosyltransferase activity towards o-aminophenol by glucocorticoids in late-foetal rat liver in utero.

1. A precocious development of UDP-glucuronosyltransferase activity (EC 2.4.1.17) towards o-aminophenol is demonstrated in 15-17 day foetal rat liver in utero after dexamethasone administration to the mother. 2. This stimulation of liver transferase activity in utero is directly proportional to the dose of dexamethasone infected. 3. Precocious development of transferase activity in utero can al...

متن کامل

Early erythropoiesis in foetal rat bone marrow: evidence for a liver-to-bone marrow relay.

Erythropoietic activity of foetal rat femoral marrow was examined during the last four days of intra-uterine life. Insignificant at day 18, it develops slowly thereafter until birth. In the non-suckled neonate (not older than two hours), it appears notably enhanced. In order to test the potential of the foetal marrow to develop precocious or increased erythropoiesis, the activity of the erythro...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2008