Neocytolysis, i.e. destruction of young red blood cells (RBC), occurs in astronauts over the spaceflight first days. Due to microgravity, a central blood pooling occurs. The consequent increased diuresis and decreased plasma volume cause haematocrit increase. Therefore, EPO synthesis is down regulated, a fact that associated to neocytolysis, leads to a fast reduction of RBC mass. We have analysed a panel of plasma and RBC parameters which can be related to young red cells destruction on blood samples drawn from four astronauts before and after a 10-11 spaceflight days. After the spaceflight, ferritin plasma levels were increased in three subjects, indicating a possible haemolytic process recently occurred. The percentage of young RBCs was decreased and a small number of those left over exposed phosphatydilserine (PS) on the outer membrane layer, thereby showing an “apoptotic-like” phenotype, able to trigger ingestion by macrophages. A decreased expression of both “protective” membrane molecules CD55 and CD47 on young RBCs was also observed.

Effects of spaceflight on erythropoiesis: a study on neocytolysis

RISSO, Angela;ANTONUTTO, Guglielmo
2008-01-01

Abstract

Neocytolysis, i.e. destruction of young red blood cells (RBC), occurs in astronauts over the spaceflight first days. Due to microgravity, a central blood pooling occurs. The consequent increased diuresis and decreased plasma volume cause haematocrit increase. Therefore, EPO synthesis is down regulated, a fact that associated to neocytolysis, leads to a fast reduction of RBC mass. We have analysed a panel of plasma and RBC parameters which can be related to young red cells destruction on blood samples drawn from four astronauts before and after a 10-11 spaceflight days. After the spaceflight, ferritin plasma levels were increased in three subjects, indicating a possible haemolytic process recently occurred. The percentage of young RBCs was decreased and a small number of those left over exposed phosphatydilserine (PS) on the outer membrane layer, thereby showing an “apoptotic-like” phenotype, able to trigger ingestion by macrophages. A decreased expression of both “protective” membrane molecules CD55 and CD47 on young RBCs was also observed.
File in questo prodotto:
File Dimensione Formato  
Space and neocytolysis.pdf

non disponibili

Tipologia: Altro materiale allegato
Licenza: Non pubblico
Dimensione 620.29 kB
Formato Adobe PDF
620.29 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11390/694437
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact