Bombesin treatment enhances vasopressin receptors in Swiss 3T3 cells
| Autor: | M. Bouzyk, Enrique Rozengurt, J. Sinnett-Smith, M. M. Civan |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Receptors
Vasopressin medicine.medical_specialty Vasopressin Time Factors Physiology Neuropeptide Biology Binding Competitive Mice chemistry.chemical_compound Downregulation and upregulation Cell surface receptor Internal medicine medicine Animals Cycloheximide Receptor Vasopressin receptor Arginine vasopressin receptor 1B Bombesin 3T3 Cells Cell Biology Arginine Vasopressin Kinetics Endocrinology chemistry Calcium hormones hormone substitutes and hormone antagonists |
| Zdroj: | American Journal of Physiology-Cell Physiology. 265:C1658-C1662 |
| ISSN: | 1522-1563 0363-6143 |
| DOI: | 10.1152/ajpcell.1993.265.6.c1658 |
| Popis: | Cells possess receptors for multiple different peptides that regulate a wide spectrum of biological processes. Although examples of homologous and heterologous downregulation have been reported, relatively little is known about the interaction between different peptides in modulating cellular activities. Here we demonstrate that pretreatment of Swiss 3T3 fibroblasts with 10 nM bombesin for 48 h enhanced the 45Ca2+ efflux acutely stimulated by vasopressin. The effect was not reciprocal, since preincubation with vasopressin did not affect the bombesin-stimulated Ca2+ efflux. Measurement of displaceable [3H] vasopressin binding demonstrated that bombesin pretreatment increases the hormonal binding by 3.8 +/- 0.2-fold (SE; n = 14) measured at 37 degrees C or at 4 degrees C. Scatchard analysis at 4 degrees C indicated that the increased binding reflects an increase in the number of vasopressin receptors without any significant effect on the apparent affinity of binding. Furthermore, addition of cycloheximide completely prevented the increase in [3H] vasopressin binding induced by bombesin. We conclude that long-term bombesin pretreatment induces heterologous enhancement of vasopressin responsiveness by increasing the number of membrane receptors. |
| Databáze: | OpenAIRE |
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