Changes in Metal Distribution of the Avian Oviduct During the Ovulation Cycle.

Summary A study was made of the metal distribution in certain functional segments (magnum, isthmus, and shell gland) of the oviduct of the domestic fowl (Gallus domesticus) in an effort to detect patterns of metal flux in these tissues which might be associated with calcium transport. Concentrations of calcium, magnesium, iron, manganese, copper, and zinc were determined by spectra] emission analysis of tissue ash from birds sacrificed at various phases of the ovulation cycle. Ash content was highest in the shell gland; calcium and copper concentrations were elevated in the isthmus and magnesium was elevated in the magnum. There appears to be a relationship between the metal concentrations and the known metabolic functions of the oviduct segment analyzed. The data also indicate that 1) the movement of trace amounts of the metals, zinc, manganese and magnesium, to the egg occurs in particular segments; 2) high copper levels are present in the isthmus; 3) the isthmus transports calcium for deposition on the shell membrane; 4) potassium and sodium are major cations of all segments analyzed.