Identification of adipose tissue primordia in perirenal tissues of pig fetuses: utility of phosphatase histochemistry.
Perirenal adipose tissue samples were obtained from fetuses removed from pregnant (crossbred) sows at 3 stages of gestation (70, 90 and 110 days). Phosphatase histochemistry, succinate dehydrogenase (SDH) histochemistry and factor VIII antigen immunocytochemistry were conducted on fresh-frozen cryostat sections. Age-associated changes in nucleosidediphosphatase (NDPase) reactions in the arteriolar system were correlated with the morphological development of the medial layer of arterioles and arteries. For instance, a strong NDPase reaction in small arterioles was associated temporally with the assumption of a normal smooth-muscle cell morphology and arrangement in the medial layer. Age-associated changes in blood vessel reactions for factor VIII antigen and alkaline phosphatase activity were not correlated with morphological development. In the youngest fetuses, alkaline phosphatase activity was evident in large and small arterioles, but in the oldest fetuses, alkaline phosphatase activity was restricted to the smallest arterioles and vessels associated with them. Arteriolar differentiation was demonstrable with either adenosine triphosphatase (ATPase) or inosine diphosphatase (IDPase) reactions. Primordial stromal cells around differentiated arterioles were reactive for ATPase but not for IDPase activities. In older fetuses, there were large areas that contained ATPase-reactive stromal cells, no adipocytes, differentiated (ATPase and IDPase) arterioles and few capillaries. Positive reactions for SDH were evident in the ATPase-reactive stromal areas that contained no adipocytes. Differentiated adipocytes were SDH- and ATPase-reactive. These data illustrate the utility of differential phosphatase histochemistry to identify adipose tissue primordia.
D017766:Acid Anhydride Hydrolases; D000273:Adipose Tissue / Q000196:embryology* / Q000201:enzymology; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D005169:Factor VIII / Q000378:metabolism; D006651:Histocytochemistry; D007120:Immunochemistry; D007668:Kidney / Q000196:embryology*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D013385:Succinate Dehydrogenase / Q000378:metabolism; D013552:Swine / Q000196:embryology
D005169:Factor VIII; D013385:Succinate Dehydrogenase; D000469:Alkaline Phosphatase; D010744:Phosphoric Monoester Hydrolases; D017766:Acid Anhydride Hydrolases; C023837:nucleoside-diphosphatase