Background: Insulin-like growth factors (IGF)-I and -II are present in milk of a number of mammalian species. The stability of IGF-I and -II in the intestinal lumen was investigated by measuring the proteolytic degradation of 125I-labeled IGF-I and IGF-II by rat (suckling and adult) intestinal luminal flushings in vitro.
Methods: Degradation of 125I-labeled IGF-I and IGF-II was assessed by measuring the generation of acid-soluble radioactivity and the reduction of the amounts of peak activity (gel filtration). Degradation was confirmed by measuring the loss of immunoreactivity and receptor activity.
Results: Incubation of 125I-IGF-I with midjejunal luminal flushings from 12-day-old suckling rats generated acid-soluble radioactivity in a time- and dose-(flushing) dependent manner, whereas incubation of 125I-IGF-II produced only minor amounts of acid-soluble radioactivity. Degradation activity in luminal flushings from adult rat intestine was several times greater than that in luminal flushings from suckling rats. Degradation of 125I-IGF-II was several times lower than that of 125I-IGF-I in the intestinal luminal flushings from suckling and adult rats. The rate of decrease in immunoprecipitable 125I-IGF-I was considerably lower than the rate of decrease in receptor-active radioactivity. Except for immunoreactivity, analyses of acid-precipitable, peak-A, and receptor-active radioactivities demonstrate that IGF-II is relatively more stable than IGF-I in luminal flushings of suckling rat duodenum, jejunum, and midjejunum.
Conclusions: These results show that the stability of IGF in the gastrointestinal lumen depends on the age of the animal and the segment of the gastrointestinal tract, as well as on the peptide isoform.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1097/00005176-199802000-00012 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Endometrial responsiveness to interferon-tau and its association with subsequent reproductive performance in dairy heifers.
J Dairy Sci
September 2024
Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada. Electronic address:
Our objectives were to evaluate the endometrial responsiveness of dairy heifers to an intrauterine infusion of recombinant bovine interferon-tau (rbIFN-τ) and to associate endometrial responses to rbIFN-τ with subsequent reproductive performance. In experiments 1 and 2, cyclic heifers were enrolled in a program for synchronization of the estrous cycle, and blood sampling and ultrasonography examinations were performed on d 0, 4, 7, 11, and 14 of the estrous cycle. In experiment 1, heifers were randomly assigned to receive an intrauterine infusion containing 2 µg of rbIFN-τ (rbIFN-τ = 19) or saline control (CTRL = 19) into the uterine horn ipsilateral to the corpus luteum (CL) on d 14 of the estrous cycle.
View Article and Find Full Text PDF[Comparison among different flushing media for intracoronary imaging with optical coherence tomography].
Zhonghua Xin Xue Guan Bing Za Zhi
February 2024
Department of Cardiology, the Second Hospital of Jilin University, Changchun 130000, China.
To explore the effects and safety of saline mixed 1∶1 with contrast medium (mixed medium) and pure heparinized saline as alternative media for optimal Optical Coherence Tomography (OCT) guided percutaneous coronary intervention (PCI). This single-center, prospective cohort study enrolled patients who underwent PCI with OCT guidance for chronic stable angina or acute coronary syndrome at the Department of Cardiology, the Second Hospital of Jilin University from October 2021 to August 2022. The target vessels were examined using OCT with three different flushing media at the same anatomical positions: contrast agent, mixed medium, and pure heparinized saline.
View Article and Find Full Text PDFHigh-Fidelity Perforator Visualization for Cadaver Dissection in Surgical Training.
Arch Plast Surg
November 2023
Department of Plastic Reconstructive and Aesthetic Surgery, Singapore General Hospital, Singapore, Singapore.
In the first half of the third century B.C., Herophilus and Erasistratus performed the first systematic dissection of the human body.
View Article and Find Full Text PDFMetabolomic evolution of the postpartum dairy cow uterus.
Mol Reprod Dev
December 2023
Animal Biotechnology Team, AgResearch, Hamilton, New Zealand.
High rates of early pregnancy loss are a critical issue in dairy herds, particularly in seasonal, grazing systems. Components of the uterine luminal fluid (ULF), on which the early embryo depends for sustenance and growth, partly determine early pregnancy losses. Here, changes in ULF from early to mid-postpartum in crossbred dairy cows were explored, linking them with divergent embryo development.
View Article and Find Full Text PDFRegulation of synthesis of polyamines by progesterone, estradiol, and their receptors in uteri of cyclic ewes†.
Biol Reprod
September 2023
Department of Animal Science, Texas A&M University, College Station, Texas, USA.
Progesterone (P4), estradiol (E2), and expression of their receptors (PGR and ESR1, respectively) by cells of the uterus regulate reproductive performance of mammals through effects on secretion and transport of nutrients into the uterine lumen. This study investigated the effect of changes in P4, E2, PGR, and ESR1 on expression of enzymes for the synthesis and secretion of polyamines. Suffolk ewes (n = 13) were synchronized to estrus (Day 0) and then, on either Day 1 (early metestrus), Day 9 (early diestrus), or Day 14 (late diestrus) of the estrous cycle, maternal blood samples were collected, and ewes were euthanized before obtaining uterine samples and uterine flushings.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!