Effect of PDGF and TGF‐β on the release of biogenic amines from invertebrate immunocytes and their possible role in the stress response

Abstract

PDGF-AB and TGF-ßl intervene in molluscan stress response, the former inhibiting and the latter inducing the release of norepinephrine and epinephrine from hemocytes. These amines are down-regulated even when TGF-ßl is added to hemolymph pre-incubated with PDGF-AB. The opposite behaviour is observed if the growth factors are reversed. The dopamine response is not affected in either case, even after the addition of CRH or ACTH. After pre-incubation with PDGF-AB or TGFßl in the presence of CRH or ACTH, norepinephrine and epinephrine release falls. These findings suggest that when the interaction is between growth factors, the order of combination is crucial, while in cases where the interaction is between growth factors and other peptides, such as CRH and ACTH, the order is of no importance.© 1997 Federation of European Biochemical Societies.

Stress and immune responses in abalone: Limitations in current knowledge and investigative methods based on other models

“…Similarly, preincubation with TGF caused elevation in noradrenaline that was not countered by the subsequent addition of PDGF, though the adrenaline levels were depressed. While added CRH and ACTH both caused increased release of noradrenaline and adrenaline, if added after the growth factors, adrenaline and noradrenaline levels were decreased [12]. These results show an integration of the effects of the molecules involved in the stress response.…”

“…Ottaviani & Franceschi [11] point out that a relationship exists between these three systems in various invertebrates, including gastropods and bivalves, but it is still poorly characterised. The stress response originates in the endocrine system, with corticotropin releasing hormone (CRH) stimulating the release of adrenocorticotrophic hormone (ACTH), leading to the release of biogenic amines, which then mediate secondary effects in the molluscs, annelids and insects that have been studied [3,11,12]. The secondary stress response involves metabolic changes in other organs, as the animal responds to the stressor and attempts to maintain homeostasis.…”

“…Bacterial killing assays [6][7][8][9][10] H. diversicolor Haemocyte counts [6][7][8][9][10] H. diversicolor [5] H. tuberculata Haemocyte morphology [56] H. asinina [57] H. cracherodii [72] not stated Phagocytosis assays [81] H. asinina [6][7][8][9][10] H. diversicolor [5] H. tuberculata Respiratory burst assays [4] H. cracherodii, H. rufesens [6][7][8][9][10] H. diversicolor [5] H. tuberculata Humoral Response Phenoloxidase assays [6][7][8][9][10] H. diversicolor Antimicrobial assays [112] H. cracherodii, H. corrugata, H. rufesens [24] H. diversicolor [100,102,103] H. rubra [99,104] not stated Stress Response Catecholamines in abalone [5,12,27] H. tuberculata Affect of stress on immunity [4] H. cracherodii, H. rufesens [6]…”

“…This link is based on immune function tests carried out after applying stressors such as altered salinity, shaking, decreased dissolved oxygen, increased concentrations of ammonia and nitrate and increased temperature. In abalone and other molluscs, both the stress response and the immune response appear to be centred on the haemocyte, as these blood cells produce mediators of stress and the main immune responses [3,11,12].…”

A dopamine beta hydroxylase from Chlamys farreri and its induced mRNA expression in the haemocytes after LPS stimulation

“…The transcript of CfDBH mRNA was also detected in the haemocytes of scallops, which suggested the catecholamines could modulate the immune defense of haemocytes in autocrine and paracrine manner resembling the macrophages of human [41]. The expression of CfDBH in haemocytes also provided helpful information to support the investigation that haemocytes could be induced by some cytokines to release catecholamines in mollusc [42].…”