The invention relates to a process for the production of pituitary hormones having human species specificity by propagating human pituitary cells in suspension in a culture nutrient medium to form undifferentiated cells and is characterized in that epithelial-like cells are selected and serially propagated in stationary culture, in which the passages into the successive culture stages are carried out in a non-traumatic way (defined), then epithelial-like cell lines, which exhibit hormone secretion, are selected and propagated in suspension culture, whereafter the pituitary hormone is recovered from the culture.  The hormones have no antigenity when used for human therapy.  They include ACTH, gonadotrophin and growth hormone. Altered cells capable of producing single hormones in contrast to the production of mixed hormones from the natural pituitary gland may be developed.  The main steps in the culture are (a) harvesting of starter culture tissue, transportation and processing for propagation, (b) stationary tissue culture stage, (c) suspension culture stage wherein the medium contains a greater quantity of 1-amino-acids and antibiotics than in the stationary culture stage; and (d) cell line and harvesting and preservation of cell suspensions.  The cultures are propagated and transferred by utilizing fragments of coverslips within a culture as seeding or starters for new cultures and transferring these fragments to new culture flasks. The invention also relates to the production of altered human pituitary cells having a nucleus containing from about 76 to 81 chromosomes including a small number of telocentric and acrocentric chromosomes and possessing pituitary hormone producing activity by a process comprising the steps of culturing fragments of human pituitary tissue in stationary culture in a nutrient medium containing about 10% by volume of human or animal serum and containing chiefly amino acids, vitamins, inorganic salts, a carbohydrate and antibiotics, transferring cells in a non-traumatic way into successive portions of culture medium, said culture being continued until a cell population density of about 1 - 100 cells per sq. cm. of vessel floor area is attained, selecting epithelial-like cells, propagating them and transferring said cells when a concentration of about 200,000 to 300,000 cells per ml. is obtained to a suspension culture system, repeatedly culturing said cells in said system at a cell population density of about 50,000 to 5 million or more cells per ml. in a nutrient medium containing a higher concentration of amino acids than the stationary culture medium until altered cells appear, which exhibit increased chromosome count, heteroploid characteristics and hormone producing activity.ALSO:The invention relates to a process for the production of pituitary hormones having human species specificity by propagating human pituitary cells in suspension in a culture nutrient medium to form undifferentiated cells and is characterized in that epithetial like cells are selected and serially propagated in stationary culture in which the passages into the successive culture stages are carried out in a non-traumatic way (defined), then epithetial-like cell lines, which exhibit hormone secretion, are selected and propagated in suspension culture, whereafter the pituitary hormone is recovered from the culture.  The hormones have no antigenicity when used for human therapy.  They include ACTH, gonadotrophin and growth hormone. Altered cells capable of producing single hormones in contrast to the production of mixed hormones in the pituitary from the natural pituitary gland may be developed.  Details of propagation of these pituitary cells are given in Division C6.