Biomaterial Database

[Pregnancy induced DNA synthesis in parenchymatous organs of the rat. Autoradiographic investigations following permanent infusion of 3H-thymidine (author's transl)]. 1976

O Klinge, and P C Werner

Autoradiographic investigations, after permanent infusion of 3H-thymidine during the whole course of pregnancy in 3 to 5 months old white Spraque-Dawley rats of 220-305 g body weight demonstrate an enhanced DNA synthesis in all cell systems tested. 1. In the liver the mean value of the proliferation index in the hepatocytes increases from a control value of 0.7% to 10.4%, in the epithelia of the portal ducts from 6.7% to 42.4% and in the sinus cells from 3.7% to 23.9% at the end of pregnancy. The corresponding values in the pancreas run up to 6.3% (3.4%) in the acinus parenchyma and 19.6% (8.8%) in the islet cells of Langerhans. In the duct epithelia no significant increase of labelled cells can be found. In the kidney, the number of DNA synthesizing tubular cells depends on their localization within the nephron: in the epithelia of the proximal tubulus the proliferation index amounts to 2.7% (0.6%), in that of the distal tubulus to 4.5% (1.4%). The highest percentual increase in comparison with the control animals results in the proximal tubular epithelia of pregnant rats. The cells of the glomerula are practically uninvolved. 2. The enhanced proliferation may rest on the influence of hypophysial or placental hormones--especially of somatotropins--as well as on an intensified function of the organs during pregnancy. Both hormonal and functional stimuli are closely mixed up in their significance for the pregnancy-induced DNA syntheses, accordingly their effect cannot be separated exactly. The hormones seemingly represent the inducing factor for the increased DNA syntheses during pregnancy which is realized in a variable amount within the organs depending on their different functional enhancement. 3. The increase of the proliferation indices ranges considerably from individual to individual, but within one single animal all cellular systems are afflicted in the same way. The individual ranges of the proliferation rates within the organs are directly proportional to the weight of the offsprings and indirectly proportional to the weight of the mother. The only exception of this is in the proximal tubular epithelium of the kidney. The important influence of adaptation drocesses to the enhanced function of an organ during pregnancy is emphasized by this fact.

UI	MeSH Term	Description	Entries
D007515	Islets of Langerhans	Irregular microscopic structures consisting of cords of endocrine cells that are scattered throughout the PANCREAS among the exocrine acini. Each islet is surrounded by connective tissue fibers and penetrated by a network of capillaries. There are four major cell types. The most abundant beta cells (50-80%) secrete INSULIN. Alpha cells (5-20%) secrete GLUCAGON. PP cells (10-35%) secrete PANCREATIC POLYPEPTIDE. Delta cells (~5%) secrete SOMATOSTATIN.	Islands of Langerhans,Islet Cells,Nesidioblasts,Pancreas, Endocrine,Pancreatic Islets,Cell, Islet,Cells, Islet,Endocrine Pancreas,Islet Cell,Islet, Pancreatic,Islets, Pancreatic,Langerhans Islands,Langerhans Islets,Nesidioblast,Pancreatic Islet
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D007686	Kidney Tubules, Distal	The portion of renal tubule that begins from the enlarged segment of the ascending limb of the LOOP OF HENLE. It reenters the KIDNEY CORTEX and forms the convoluted segments of the distal tubule.	Distal Kidney Tubule,Distal Renal Tubule,Distal Kidney Tubules,Distal Renal Tubules,Kidney Tubule, Distal,Renal Tubule, Distal,Renal Tubules, Distal,Tubule, Distal Kidney,Tubule, Distal Renal,Tubules, Distal Kidney,Tubules, Distal Renal
D007687	Kidney Tubules, Proximal	The renal tubule portion that extends from the BOWMAN CAPSULE in the KIDNEY CORTEX into the KIDNEY MEDULLA. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the U-shaped LOOP OF HENLE.	Proximal Kidney Tubule,Proximal Renal Tubule,Kidney Tubule, Proximal,Proximal Kidney Tubules,Proximal Renal Tubules,Renal Tubule, Proximal,Renal Tubules, Proximal,Tubule, Proximal Kidney,Tubule, Proximal Renal,Tubules, Proximal Kidney,Tubules, Proximal Renal
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D010179	Pancreas	A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011270	Pregnancy, Animal	The process of bearing developing young (EMBRYOS or FETUSES) in utero in non-human mammals, beginning from FERTILIZATION to BIRTH.	Animal Pregnancies,Animal Pregnancy,Pregnancies, Animal
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M