Prolactin alters the expression of integumental glycoconjugates in the red-spotted newt, Notophthalmus viridescens.

Prolactin (PRL)-mediated changes in the texture and secretory activity of the skin in adult red-spotted newts may involve alterations in the distribution and/or expression of structural and secretory epidermal glycoconjugates. To explore this possibility, skin samples were obtained from groups of conditioned animals that had received injections of either ovine prolactin or amphibian saline over a 14-day period. Glycoconjugates within the epidermis and cutaneous glands were examined by means of lectin histochemistry using a panel of eight HRP-labelled lectins. PRL increased levels of sialic acid and n-acetylglucosamine in the stratum corneum. In contrast, glycoconjugates containing fucose, galactose, n-acetylgalactosamine, and galactose-(1,3)-n-acetylgalactosamine were decreased by PRL within both glands and epidermis. These results suggest that the integumental effects associated with prolactin in the red-spotted newt are mediated, at least in part, through the alteration of epidermal and glandular glycoconjugates.

Lectin histochemistry of the human amnio-chorionic membrane complex.

The presence and distribution of glycoconjugates within the human amnion, chorion, and decidual tissues was examined histochemically following incubation with HRP-labelled lectins. Glycoconjugates within the cytoplasm of cells as well as the extracellular matrix of the maternal decidual layer and fetal chorio-amniotic membranes reacted selectively with OFA, LTA, WGA, PSA, UEA-I, GSAI-B4, RCA-I, LFA, VVA, PHA-E, and GSA-II. Conjugated lectins specific for L-fucose-stained components of amnion, chorion laeve, and decidua while other lectins bound glycoconjugates within decidua and at the junction between maternal decidua and fetal chorionic tissue. These observations suggest that the amnio-chorionic membrane complex may include several histochemically distinct and specialized subpopulations of glycoconjugates distributed within cells and the extracellular matrix. Although specific functions for these glycoconjugates have not been elucidated, they may mediate transport of amniotic fluid and/or facilitate maternal recognition of the developing fetus.

Prolactin secretion by human chorion-decidua in vitro: influences of mode of delivery and agents that modify prostaglandin synthesis.

Prolactin production by human decidua was examined with the use of a short-term tissue explant system. Decidua obtained after normal spontaneous vaginal deliveries produced significantly more prolactin than did tissue obtained after elective repeat cesarean section deliveries in the absence of labor (P less than 0.005). Cytosolic prolactin levels did not differ between the two delivery modes. Oxytocin (4.3 X 10(-11) M to 4.3 X 10(-6) M) and eicosatetraenoic acid (10(-7) M to 10(-4) M) had no effect on prolactin production or storage by decidual tissue. Indomethacin at 10(-4) M reduced only levels of stored prolactin but had no effect on stored or produced prolactin at lower concentrations (10(-7) M to 10(-5) M). Arachidonic acid (10(-4) M) suppressed both production and storage of prolactin (P less than 0.05). Decidual tissue from the two delivery modes did not differ in response to the above agents. Although the exact mechanism(s) remains obscure, these results indicate decidual prolactin production is altered by some aspect of labor. The possible involvement of prostaglandin precursors in mediating this production cannot be excluded.

Prolactin binding sites on human chorion-decidua tissue.

An effective procedure has been developed and utilized to demonstrate the presence of prolactin receptors on the plasma membranes of human chorion-decidua cells. Particulate fractions from human chorion-decidua sedimenting between 1,500 and 45,000 x g display optimal binding of 215I-labeled ovine prolactin when incubated at a membrane protein concentration of 200 micrograms per assay tube for 2 hours at 22 degrees C. Specific binding was increased by pretreatment of the membrane particles with 5M magnesium chloride to remove endogenous prolactin. These receptors show binding parameters (affinity, 0.92 x 10(9) L/mode; capacity, approximately 80 fmoles/mg) similar to those of lactogenic receptors in the rabbit mammary gland and, the rabbit and rat liver. The presence of prolactin receptors in human chorion-decidua suggests that may play a role in mediating local action(s) of prolactin such as involvement in the decidualization reaction or in maintaining fetal osmoregulation.

Effect of betamethasone on fetal macrophage function: depression of adherence of immunoglobulin-coated red blood cells.

In this study, betamethasone was found to significantly inhibit the binding of immunoglobulin-coated O Rh-positive red cells to fetal macrophages. At a dose of 0.15 mg%, betamethasone depressed immune rosette formation to 44% of controls (p less than 0.01); and a dose of 0.60 mg% resulted in an average depression to 22%. This in vitro effect may reflect important alterations in in vivo immune function in infants delivered from mothers who have received antenatal corticosteroids.

Hyperpigmented patches in the skin of the newt Notophthalmus viridescens.

In the integument of the red-spotted newt there occasionally appear patches of skin which are at the same time melanistic and iridescent. Such hyperpigmented patches have been found on the back, on the tail and on the dorsal surface of both fore and hind limbs. Cytological examination of several such areas revealed the presence of large numbers of chromatophores distributed throughout the dermis. The majority of the chromatophores consisted of atypically large and dendritic melanophores, which contained typical pigment granules. The iridescence resulted from a high incidence of iridophores. Xanthophores also were found in considerable abundance. This extensive and apparently random intermingling of melanophores, iridophores and xanthophores in limited areas constitutes a striking exception to the usual distributional patterns of pigment cells in this animal.

Nature of the rabbit acrosome reaction-inducing activity of follicular fluid.

Follicular fluid samples from rabbits, cats, pigs, women and cows had acrosome reaction-inducing activity (ARIA) on rabbit spermatozoa as determined by differential staining after incubation with these fluids. Activity was retained after dialysis and at least 50% was found to be labile when heated to 56 degrees C for as little as 20 min. The induction of the acrosome reaction by bovine follicular fluid showed a dependence on the concentration of follicular fluid and spermatozoa and on calcium ions, and had a pH optimum of approximately 8. Enzyme treatments showed that proteases destroyed the ARIA and this activity was completely blocked by treatment of bovine follicular fluid with goat anti-bovine antiserum. Electron microscope observations indicated the similarity of the reactions observed to that occurring in vivo. It is concluded that the rabbit acrosome reaction inducing-activity of bovine follicular fluid is a serum component(s), probably a protein(s) of high molecular weight.