HISTOCHEMICAL-STUDIES OF MAMMARY-GLAND PARENCHYMA IN PREGNANT NALI EWES

Mammary gland parenchyma was studied in 15 sheep, three each at Days 3 0, 60, 90, 120 and 150 of pregnancy. The epithelial tissue at Days 30 and 60 was rudimentary and contained only the Periodic acid-Schiffs (P AS) positive glycogen material and Fe. Fat and protein appeared in alv eolar cells at Day 90 of pregnancy. Glandular cells at Day 120 of preg nancy showed increase in staining intensity of all constituents. The P AS positive material at this stage was saliva resistant and concentrat ed more in intranuclear cytoplasm, it did not stain for acid mucopolys accharides, only for neutral fats. Free fatty acids could not be locat ed in the alveolar cells. Protein, Ca and Fe were mixed with other cyt oplasmic substances. Increase in their cellular concentration and rele ase into alveolar lumina by Day 150 suggested functional maturity of t he gland at this stage of pregnancy. These findings can be used in bio chemical studies on isolated mammary gland tissues to assess the quant ity and possible source of various constituents specific to milk in sh eep at different days of pregnancy.