Uteroglobin and the accumulation of progesterone in the uterine lumen of the rabbit

Abstract

This study was undertaken to determine whether the influx of progesterone into the uterine lumen of the rabbit, in the preimplantation period, is dependent onuteroglobin (UGL). Rabbits were ovariectomized and, three months later, treated with two defferent doses of progesterone. Purified UGL was injected into one uterine horn and, as a control,immunoglobulin G (IgG) was injected into the other. After four days, the animals were sacrificed their uteri flushed, and the progesterone content of the washes was determined by radioimmunoassay.Animals with the lower serum progesterone level (2.8 ng/ml) had a significantly different uterine horn progesterone content. The hormone accumulation in the horn containing UGL was 2.3 to 7.5 times higher than in the horn containing IgG. Animals with a higher serum progesterone level (7.2 ng/ml) showed no differences. The hormone content was equally high in both horns, presumably due to the synthesis of endogenous UGL being reactivated by the hormone treatment.The validity of these experiments as models for the events during early pregnancy and the physiological role of progesterone available inside the uterus are discussed.

Uteroglobin: a novel cytokine?

“…One of the first properties reported was its ability to enhance the growth of preimplantation blastocysts, hence the name blastokinin [1]. Subsequently, it was found that UG binds progesterone [8], and it was proposed that UG acts as a carrier and/or scavenger [138] of this steroid hormone, reducing its toxicity to the early developing embryo [139]. Several years later, binding of PCBs [14] and retinol [15] by UG was also reported.…”

Human Uteroglobin Gene: Structure, Subchromosomal Localization, and Polymorphism

“…This protein possesses varied biochemical and biological properties including phospholipase A2(PLAA)-inhibitory (Levin et al, 1986), immunomodulatory (Mukherjee et al, 1982(Mukherjee et al, , 1983)/antiinflammatory properties (Levin et al, 1984;Miele et al, 1988;Mukherjee et al, 1988;Camussi et al, 1990a,b,c;Chan et al, 1990Chan et al, , 1991Di Rosa and Ialenti, 1990;Ialenti et al, 1990;Facchiano et al, 199l;Tetta etal, 1991;Perretti etal, 1991;Cabre' et al, 1992;Moreno et al, 1995). It binds xenobiotic agents such as progesterone (Beato, 1976(Beato, , 1977Fridlansky and Milgrom, 1976;Alger etal., 1980;Bochskanl and Kirchner, 1981;Peter, 1992), polychlorinated biphenyls (Gillener et al, 1988;NordlundMoller et al, 1990), and retinol (Lopez de Haro et al, 1994). Because of its potent PLA2-inhibitory, immunomodulatory/antiinflammatory activities and its high level of constitutive expression in the pulmonary system, it has been suggested that this protein may play critical roles in controlling inflammation in the airway (Mukberjee etal., 1988).…”